Driver error in syslog

[2E0PGS]

Hi I have the following entry in my syslog:

Mar 17 14:20:36 raspberrypi wee_device[2077]: The driver user.wmII does not include a configuration tool: 'module' object has no attribute 'configurator_loader'

Any ideas?

[2E0PGS]

Nevermind a reboot of the system fixed that.

[jardiamj]

Hi! I am glad that the driver is working for you. I never thought someone else besides me would find it useful since this Weather Station is so old but I am glad you are using it. My system has been running with that driver without issues for a few months now, let me know if you find any bugs. FYI, I have code in the driver that allows you to enter the calibration values into the station but I haven't had the time to implement that in weewx, I might do that in the near future. That might be useful, for example, if you have a different rain bucket size that the default one in the US (0.01"). This is what the manual says: ----------------------------------------- Default CAL = 100 (for 0.01" rain collector). If you have a 0.2 mm rain collector, you must change the calibration number. First adjust the console to display rainfall in millimeters and then change CAL to 0005. (For instructions on how to change CAL, see “Changing Calibration Numbers” below). Be aware that the console will revert to its default calibration (i.e., inches) if it loses power. ------------------------------------------ Right now the rain calibration number is hard coded into the driver (100), so if your rain bucket is the metric one (0.2 mm rain collector) you would have to change that in the driver itself, on line 123: self.rncal = 100 Jardi.

…

On Sun, Mar 17, 2019 at 8:02 AM Peter Stevenson ***@***.***> wrote: Closed #1 <#1>. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#1 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABCc3MwJ1_6V93RzW5LcOOhffYR8Nf3Oks5vXlkjgaJpZM4b4a0g> .

[2E0PGS]

Thanks for the tips on calibration. I need to investigate this warning message: Mar 17 20:28:35 weewx weewx[363]: engine: 2019-03-17 20:28:34 GMT (1552854514) LOOP value 'outHumidity' 141 outside limits (0.0, 100.0). I suspect it's some simple math that needs changing in the code that converts the value into a %.

I have two of these weather stations and there is hardly any software that supports them besides the expensive and old Davis software. So it's awesome to make better use of a still very accurate peice of hardware.

Thanks for your driver.

[jardiamj]

Which Station do you have? My Weather Monitor II returns the humidity as a percentage already so I there is no calculation done in the driver, I am attaching the file with the Technical Reference that I used to write the driver. No all the stations report the same values nor in the same order, so look in the file for the structure of the LOOP packets that you station returns when you send a LOOP command. Let me know if I can be of any further assistance, and if you make modifications to support your station I would like to see if I can incorporate that in the current driver so someone else might benefit from it. Jardi.

On Sun, Mar 17, 2019 at 1:30 PM Peter Stevenson ***@***.***> wrote: Thanks for the tips on calibration. I need to investigate this warning message: Mar 17 20:28:35 weewx weewx[363]: engine: 2019-03-17 20:28:34 GMT (1552854514) LOOP value 'outHumidity' 141 outside limits (0.0, 100.0). I suspect it's some simple math that needs changing in the code that converts the value into a %. I have two of these weather stations and there is hardly any software that supports them besides the expensive and old Davis software. So it's awesome to make better use of a still very accurate peice of hardware. Thanks for your driver. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#1 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABCc3GVEAYzTlY-DwCW79WJeouuwIsdxks5vXqYBgaJpZM4b4a0g> .

2/11/98 4:52 PM 48 Monitor, Wizard, Perception GroWeather, Energy, & Health WeatherLink Protocol 02-11-98 Rev 3.3 Table of Contents: I. Introduction II. Definitions III. Pseudo code description of WeatherLink command processing loop. IV. Code illustration of the Communication functions used in the examples. V. Link Types and Revision Levels VI. Command Description VII. Command Summary VIII. Illustrated Examples A. Reading Calibrated Data 1. Temperature CAL 2. Humidity CAL 3. Barometer 4. Rain 5. Wind Speed 6. Rain Rate 7. UV MED's B. Using the LOOP command C. Using MDMP command D. Invalid Data values E. Calculated Data values 1. Wind Chill 2. Dew Point 3. Temperature-Humidity Index 4. THSWI 5. Wind Run 6. Degree-Days 7. Solar Energy 8. UV Dose 9. Rain Rate F. CRC Checking G. Reading Hi/Low Times and Dates IX. Memory addresses. A. Monitor, Wizard, and Perception Station B. Monitor, Wizard, and Perception Link C. GroWeather Station D. GroWeather Link E. Energy Station F. Energy Link G. Health Station H. Health Link Appendices (Contained in "appendix.txt") A Bar/Power Bit definitions B Control Module communication status codes (AOM Status) C Model Numbers D Power Voltage Codes E THSWI Latitude Codes F Wind Direction Sector Codes G1 GroWeather Alarm Bits G2 ET Status bits G3 Leaf Wetness Data/Status byte in the LOOP packet. E1 Energy Alarm Bits H1 Health Alarm Bits I. Introduction This document is a technical description of the software interface to both the Standard WeatherLink, which can connect to the Monitor, Wizard, and Perception models, and the GroWeather WeatherLink, the Energy WeatherLink, and the Health WeatherLink. The WeatherLink interprets commands sent by a PC over an RS232C serial link (8 bits, 1 stop bit, no parity). The commands are a combination of ASCII and binary data. The command structure and format are almost identical for the 4 kinds of WeatherLink, but the available data and their locations are different. The diagram below illustrates the relationship between the PC, WeatherLink, and Weather Station. The sensor image, archive image, and the archive memory belong to the WeatherLink. As shown in the diagram the PC sends commands and receives data from the WeatherLink. The WeatherLink sends commands and receives data from the Weather Station. Data is contained in both the WeatherLink and the Weather Station. You will notice you can read data from the WeatherLink faster than the Weather Station. Therefore, if the data exists in the WeatherLink and is being updated fast enough for your purposes, read it from the WeatherLink. Study the "Command Processing Loop" carefully to understand what is in the WeatherLink and when it is updated. "RRD" commands read from the WeatherLink. "WRD" commands read from the Weather Station. The addresses of the data available in the WeatherLink and the Weather Station are given in section IX. cmds cmds (Monitor Station) PC -> Weather -> Weather Station (Wizard Station) Link (Perception Station) data data (GroWeather) <- . <- (Energy Station) . (Health Station) . sensor image archive image archive memory The Appendices, in the separate file "appendix.txt", contain descriptions of coded numerical values and Bit definitions. Please note Davis Instruments is not responsible for any damages your use of this information may cause. Furthermore, we reserve the right to modify our designs without notice. II. Definitions station processor memory - 256 bytes of memory directly accessible by the station processor, organized into 2 banks of 256 nibbles. link processor memory - 256 bytes of memory directly accessible by the link processor, organized into 2 banks of 256 nibbles. archive memory - 32K of memory where weather data is stored before downloading to PC. sensor image - Memory containing the latest data from the weather station. Part of the link processor memory archive image - Memory where archive entries are assembled before being written to the archive memory. Part of the link processor memory III. Pseudo code description of WeatherLink command processing loop. All references to Inside temperature apply to Soil temperature on the GroWeather station. Items marked (G) are only applicable to the GroWeather station (E) are only applicable to the Energy Station (H) are only applicable to the Health Station (O) are only applicable to the Monitor, Wizard, & Perception (N) are only applicable to the GroWeather, Energy, & Health // Initialize the Link chip memory Set archive interval to be 30 minutes. Set sample interval to be 20 seconds. Test archive memory. If (memory test passes) Do a beep on the weather station. /* Wind speed and wind direction are read and stored in the sensor image each time around the loop. Temperature is read once for every ten wind speed readings. Humidity, Barometer, and Rain are updated every time the sensor image is updated. */ while (1) // beginning of command processing loop GetWindSpeed (); Test for new Gust Value; GetWindDirection (); For every 10 wind speed reads { read Inside and Outside temperature; Read Rain Rate (N) read Solar Rad (N) read UV Intensity (H) read Alarm and Control-Module communication status (N) Check current Outside Temp for new Hi/Low in this period And record in archive image. Check for new Hi Rain Rate (N) Check for new Hi Solar Rad (H) Check for new Hi UV Intensity (H) } if (in loop mode) Transmit copy of sensor image. if (time to sample sensor image) Sample sensor image: Add current data values for variables that are averaged: Inside & Outside Temperature Wind Speed Solar Radiation (N) UV Intensity (H) If wind speed is > wind threshold (0), then add one to the direction bin corresponding to the current wind direction Read other values not read in above: (GetRBH) read Rain read Barometer read outside Humidity read inside Humidity (H) (O) read Wind Run (G) (E) read Total ET (G) read Total Growing Degree-Days (G) read Total Heating, Chill, Cooling, & THI Degree-Days (E) read Total Solar Energy (G) (E) read Bar and Power status bits (N) read Leaf Wetness value (G) read Rain Cal (N) Every 18 seconds collect data from the ET Sensors to calculate hourly ET (G) if ( Time to check archive clock ) // Every 16 seconds. { Call GetRBH as above (N) if (it is time to calculate ET) (G) calculate ET and store in archive Image (G) if (lastArchiveTime - currentTime >= archiveInterval) { // Make sure the sensor image is up to date. Call GetRBH as above (O) // Fill in the archive image before archiving // Hi and Low Outside temps are already set (see above) // The following reads are stored in the sensor image. Read current barometric pressure. Read current outside humidity. Read the current Leaf Wetness Value (G) Read current inside humidity. (H) (O) // The following are incremental values derived from the difference between the current value and the previous value Calculate rain in period. Calculate Wind Run in Period (G) (E) Calculate Growing Degree Days in period (G) Calculate Heating Degree Days in period (E) Calculate Wind Chill Degree Days in period (E) Calculate Cooling Degree Days in period (E) Calculate Temp-Hum-Index Degree Days in period (E) Calculate Solar energy in Period (G) (E) Calculate UV Dose in period (H) // The following are average values are derived by dividing an accumulator by the number of samples taken Calculate average Inside temperature for period. Calculate average Outside temperature for period. Calculate average wind speed for period. Calculate Average Solar Rad for period. (N) Calculate Average UV Intensity (H) Calculate dominant wind direction for period Finally, read the primary power voltage code from the station (G) (E) Write data to archive memory. Update last archive time: (O) Set the "last time" to the current station time (N) set the "last time" so that the next archive happens on the hour Clear Hi/Low entries in Archive image Clear Accumulators and sample count Set the "Previous" registers to the current values Reset ET data to FFFF (G) } // create archive record } // 16 second polling if (A command is available) Process the command. } // End while (1)... IV. Code illustration of the Communication functions used in the examples. The functions "put_serial_char()", "put_serial_string()", "send_unsigned()", "get_serial_char()" "get_acknowledge()", "fill_buffer()", and "fill_crc_buffer()" are used in the examples in the next sections to send commands and data to the WeatherLink. You must provide these functions. The illustrations given here are for reference. All of the example code included with this programmer's reference disk assumes that the "int" data type is a 16 bit (2 byte) signed number. On some machines you may be required to use the "short int" data type. In most cases, the "char" data type is explicitly stated as being unsigned. In a few places (i.e. Hum Cal on GroWeather, etc.) a one byte number needs to be treated as a signed value. "receive_buffer" is an external (global) array of unsigned char that is at least 32K in length (the size of the SRAM). /* +----------------------------------------------------------+ Output a character to current serial port. */ int put_serial_char (unsigned char c) { // write character c to the current serial port } /* +-------------------------------------------------------------+ Output a string to current serial port. */ int put_serial_string (char *s) { int i; for (i = 0; s [i] != '\0'; i++) put_serial_char (s [i]); } /* +-------------------------------------------------------------+ Outputs the unsigned integer (16 bits) to the current serial port. assumes "Intel" least significant byte first. */ int send_unsigned (unsigned d) { unsigned char *cp; cp = (unsigned char *) &d; put_serial_char (*cp); // Low order byte put_serial_char (*(cp+1)); // Hi order byte } /* +-------------------------------------------------------------+ Read a character from the current serial port. */ int get_serial_char () { int c // read a character from the current serial port and assign it to c // If there has been a timeout or some other error, set c to a negative // value that indicates the type of error return c; } /* +-------------------------------------------------------------+ anticipates an ACK to verify that the link has understood the command it has just received. If the character received is not ACK, or there has been some serial error (i.e. timeout), return an error value, otherwise return OK */ int get_ acknowledge () { int c c = get_serial_char(); if (c == ACK) return OK; else if (c < 0) // serial error return serial_error_code; else // did not receive ACK return c } /* +------------------------------------------------------------------+ Read a series of bytes from the current serial port and store them in the receive buffer. */ int fill_buffer (int n) { int i; for (i=0; i<n; i++) { c = get_serial_char(); if (c >= 0) recieve_buffer[i] = c; else // there has been an error getting the next character return serial_error_code; } return OK; // we have read in n bytes } /* +------------------------------------------------------------------+ Read a series of bytes from the current serial port, perform a CRC check on the data, and store them in the receive buffer. */ int fill_crc_buffer (int n) // n includes the CRC bytes { int i; int crc = 0; // initialize the CRC checksum to 0 for (i=0; i<n; i++) { c = get_serial_char(); if (c >= 0) { recieve_buffer[i] = c; // Store the data crc = crc_table [(crc >> 8) ^ c] ^ (crc << 8); } else // there has been an error getting the next character return serial_error_code; } if (crc == 0) return OK; // we have read in n bytes and the CRC is OK else return CRC_ERROR; // The CRC check failed. } V. Link Types and Revision Levels WeatherLink hardware modules can be classified by the station model they are intended for, and by revision level. There is one link type for the Monitor, Wizard, and Perception stations. The WeatherLink logs all the sensors for each of these stations, Any sensor or calculated value that the station does not support will be filled with the appropriate Invalid Data value (see below). The GroWeather, Energy, and Health stations are substatialy different from each other, both in the sensors supported, and in the types of calculated values. The corresponding Links are therefore also different. The primary difference, from the programmer's viewpoint, is the memory locations of the desired data which can be found in the corresponding memory address table below. There are 3 different revision levels of WeatherLink modules. These represent changes and upgrades made over the life of the product. The Rev C (and earlier) level is only used for Monitor/Wizard/ Perception Links. This version does not support the use of SR modems for communicating with the PC at distances greater than 50 feet The only difference between Monitor Links made at Rev D and Rev C is that the Rev D WeatherLinks support the use of SR modems. The GroWeather, Energy, and Health Links are also manufactured at the Rev D level. The Rev E Link implements a slightly different communication protocol between it and the PC to provide greater communication reliability. This consists, primarily, of extra CRC information that must be provided by the PC so that the WeatherLink can verify every command. Also, ALL data returned by the WeatherLink has a CRC code included, not just LOOP, MDMP, and SRD data. This means that the Rev E link is software incompatible with previous versions. The actual commands used to program a Rev E link, however, are the same as the corresponding Rev D link. Two additional commands are added to allow Rev E links to operate with the Rev D communication protocol ("Rev D Emulation Mode"). In addition, the GroWeather and Energy versions of the Rev E link implements a simple powersavings procedure with the AOM for use with solar powered radio installations. At this time only the GroWeather link is available in Rev E versions. Contact Davis' technical support at support@davisnet.com for information on getting Energy or Health versions of the Rev E link if required. Most of the included software examples assume you are NOT using a Rev E WeatherLink. Please read the "CRC Checking" (section VIII-F) for information on how to generate the necessary CRC codes. Or, read the description of the "CRC0" command for how to disable CRC command checking. VI. Command Description Commands must be in upper case and terminated with a carriage return (0dh). Do not insert spaces between binary data arguments. If an argument description uses the character '|' then one byte of data is to be formed from the 4 bit values on either side. For example: "bank | n-1" becomes the single byte "0x13" where bank = 1 and n = 4 Rev E links must also include a two byte CRC code with each command so that the WeatherLink can verify correct transmission. The CRC code is transmitted BEFORE the command. It is possible to program Rev E links to use the Rev D communication protocol, if desired. If a command is understood, an ASCII 6 (0x06) (ACK) is returned (before any returned data). If the command was not understood, an ASCII 33 (0x21) (!) is returned. Note that this implies that the command passed its CRC check sum if the link is a Rev E. For Rev E links, if the command does not pass its CRC check sum, then an ASCII 24 (0x18) (CAN) is returned. Some commands return a data stream and a CRC check sum. The generator polynomial for the check sum is x^16 + x^12 + x^5 + 1 (CRC-CCITT backward). All binary data is transferred in "Intel" format: least significant byte first. In addition, multi-nibble data values on the station are stored least significant nibble first. This does not make a difference when you look at byte sized pieces of memory, since the Link will correctly align the nibbles when sending byte data. Use the appropriate table in section IX to determine the memory locations and sizes for the data you would like to operate on. If you read data with an odd length, the upper nibble of the last (most significant) byte will be set to 0, not sign extended. If you write data with an odd length, the upper nibble of the last byte will be ignored. Sign extension is taken care of for data in the sensor image and archive image on the link. The commands "RRD" and "RWR" operate on the link processor memory. These commands execute faster than the "WRD" and "WWR" commands which operate on the station processor memory. The MDMP command is only available on the GroWeather, Energy, and Health Links. The CRC0 and CRC1 commands are only available on Rev E links. DMP Transfer the contents of the archive memory beginning at address 0 using the XMODEM CRC protocol. This command can be used with any standard communication package (i.e. Procomm). The archive memory is organized as a set of equal sized archive records. The appropriate link memory addresses section contains a description of the size and structure of an archive image, which is the same as the format of the archive records. i.e. put_serial_string ("DMP"); put_serial_char (0x0d); MDMP Dumps an image of the current contents of the Station processor memory to the serial port. This typically takes around 6 seconds and is much faster than requesting lots of pieces separately. 256 bytes are sent along with a 2 byte CRC check sum in a similar fashion to the SRD command below. The memory tables below show how this data is organized. See "Using the MDMP command" (section VIII-C) below for how to do the appropriate bit masking and shifting to extract data from the received data. NOTE: MDMP uses archive memory 7F00-7FFF to record the memory image from the station before sending it on the computer. This archive memory is not available for normal archive purposes, but the last MDMP can be read by using the SRD command, or the DMP command. The MDMP command is only available on the GroWeather, Energy, and Health Links. put_serial_string ("MDMP"); put_serial_char (0x0d); LOOP 65536-n Send 'n' packets of weather data (sensor image) from the WeatherLink. The first byte (01) signals the start of a new block. This is followed by binary data (15 bytes for the Monitor/Wizard/Perception, 33 bytes for the GroWeather, 27 bytes for the Energy, or 25 bytes for the Health) and a 2 byte CRC check sum. The CRC check sum is calculated on the data only. The "start of block" byte is not included in the CRC calculation. See "CRC Checking" (section VIII-F) below for how to use the CRC information. Monitor, Wizard, and Perception Sensor Image: start of block 1 byte inside temperature 2 bytes outside temperature 2 bytes wind speed 1 byte wind direction 2 bytes barometer 2 bytes inside humidity 1 byte outside humidity 1 byte total rain 2 bytes not used 2 bytes CRC checksum 2 bytes -------- 18 bytes GroWeather Sensor Image: start of block 1 byte Archive memory address of the next Archive record 2 bytes Bar/Power status bits 1 byte See Appendix A Soil temperature 2 bytes Air temperature 2 bytes wind speed 1 byte wind direction 2 bytes barometer 2 bytes Rain Rate 1 byte outside humidity 1 byte total rain 2 bytes Solar Radiation 2 bytes Total Wind Run 3 bytes Total ET 2 bytes Total Degree-Days 3 bytes Total Solar Energy 3 bytes Alarm Bits and AOM status 3 bytes See Appendices G1 & B Leaf Wetness Data and status 1 byte See Appendix G3 CRC checksum 2 bytes -------- 36 bytes Energy Sensor Image: start of block 1 byte Archive memory address of the next Archive record 2 bytes Bar/Power status bits 1 byte See Appendix A Inside temperature 2 bytes Outside temperature 2 bytes wind speed 1 byte wind direction 2 bytes barometer 2 bytes Rain Rate 1 byte outside humidity 1 byte total rain 2 bytes Solar Radiation 2 bytes Total Wind Run 3 bytes Total Solar Energy 3 bytes Alarm Bits and AOM status 3 bytes See Appendices E1 & B CRC checksum 2 bytes -------- 30 bytes Health Sensor Image: start of block 1 byte Archive memory address of the next Archive record 2 bytes Bar/Power status bits 1 byte See Appendix A Inside temperature 2 bytes Outside temperature 2 bytes wind speed 1 byte wind direction 2 bytes barometer 2 bytes Rain Rate 1 byte total rain 2 bytes Solar Radiation 2 bytes Inside humidity 1 byte outside humidity 1 byte UV Intensity 1 bytes UV Dose 2 bytes Alarm Bits and AOM status 3 bytes See Appendices H1 & B CRC checksum 2 bytes -------- 28 bytes Example: put_serial_string ("LOOP"); send_unsigned ((unsigned) (65536 - n)); put_serial_char (0x0d); See "Using the LOOP command" (section VIII-B) for examples of how to extract data from a Loop image RRD bank address n-1 Read 'n' nibbles from the link processor memory from 'address' in bank 'bank'. n = 1...8 On Rev E links, the data returned will also include a 2 byte CRC code. See "CRC Checking" (section VIII-F) for how to use the CRC information. put_serial_string ("RRD"); // Send the command. put_serial_char (bank); // bank = 0 or 1. put_serial_char (address); // address = 0..FF put_serial_char (n - 1); // Get n nibbles.. put_serial_char (0x0d); // Send CR... RWR bank | n-1 address data Write 'n' nibbles of 'data' into the link processor memory beginning at 'address' in bank 'bank.' n = 1..8 put_serial_string("RWR"); // Send the command. put_serial_char(0x13); // bank = 1 n = 4 put_serial_char(0x54); // address = 54h (Last Archive Time) send_unsigned (0); // write 0. put_serial_char(0x0D); // Send CR... SRD address n-1 Read 'n' bytes of archive memory beginning at 'address.' Both 'address' and 'n-1' are 16 bit numbers between 0 and 0x7FFF. A two byte CRC checksum is sent at the end of the data stream. See "CRC Checking" (section VIII-F) for how to use the CRC information. put_serial_string ("SRD"); // Send the command. send_unsigned (address); // Start sending from address. send_unsigned (n-1); // Send n bytes. put_serial_char (0x0d); // Send CR... SWR address data Write 'data' (one byte) to 'address' in archive memory. 'address' is a 16 bit number between 0 and 0x7FFF. put_serial_string ("SWR"); // Send the command. send_unsigned (address); // Send two byte address. put_serial_char (data); // Send byte of data. put_serial_char (0x0d); // Send CR... WRD n | bank address Read 'n' nibbles of data from the station processor memory starting at 'address' in bank 'bank'. For bank 0 use 'bank' = 2 for bank 1 use 'bank' = 4. A maximum of 8 nibbles can be read. On Rev E links, the data returned will also include a 2 byte CRC code. See "CRC Checking" (section VIII-F) for how to use the CRC information. put_serial_string ("WRD"); // Send read command. put_serial_char (0x44); // read 4 nibbles from bank 1. put_serial_char (0xB0); // Read beginning at B0h. // (Period Length on GroWeather) put_serial_char (0x0D); // Send CR... WWR n | bank address data Write 'n' nibbles of data to the station processor memory starting at 'address' in bank 'bank'. For bank 0 use 'bank' = 1 for bank 1 use 'bank' = 3. A maximum of 8 nibbles can be written. put_serial_string ("WWR"); // Send write command. put_serial_char (0x31); // n = 3, writing to bank 0. put_serial_char (0x34); // Write to AAh.= // Daily ET Alarm Threshold on GroWeather send_unsigned (0x0FFF); // Send 4095 or 0FFFh. put_serial_char (0x0D); // Send CR... SAP n Set the archive interval to 'n' minutes. 'n' is one byte. put_serial_string ("SAP"); // Send the command. put_serial_char (n); // Set interval to 'n' minutes. put_serial_char (0x0D); // Send CR... SSP 256-n Set the time interval between samples of the sensor image in the WeatherLink to 'n' seconds. 'n' is one byte. At each sampling instant the sensor image is sampled and variables that are "averaged" are accumulated. The maximum number of samples in an interval is 255. put_serial_string ("SSP"); // Send the command... put_serial_char ((unsigned char) (256 - newSamplePeriod)); put_serial_char (0x0D); // Send CR... STOP Tell the WeatherLink to stop it's constant updating of weather information from the weather station. The command also disables the archive timer on the WeatherLink. Stopping weather station reads allows the WeatherLink to process commands more quickly. put_serial_string ("STOP"); put_serial_char (0x0d); START Tell the WeatherLink to begin "reading" the weather station and archiving weather information. This command is only needed if you have previously sent a STOP command. put_serial_string ("START"); put_serial_char (0x0d); ARC Force a write to archive memory. put_serial_string ("ARC"); put_serial_char (0x0d); IMG Force a sampling of the sensor image. put_serial_string ("IMG"); put_serial_char (0x0d); DBT Disable the archive timer. put_serial_string ("DBT"); put_serial_char (0x0d); EBT Enable the archive timer. put_serial_string ("EBT"); put_serial_char (0x0d); CRC0 Disable CRC command checking for Rev E links. This command will set a Rev E WeatherLink into Rev D emulation mode. This means that CRC check sums are not required (not allowed either!) for commands sent to the WeatherLink. Also, only LOOP, MDMP, and SRD data from the WeatherLink include CRC check sums. If CRC command checking is enabled when you issue this command, you MUST include the CRC code. CRC command checking is only disabled AFTER the command is received and validated. The CRC code is given below. CRC0 command is only available on Rev E Links. Note, the last character of the command is an ASCII zero character. put_serial_char (44); // CRC code first byte (decimal) put_serial_char (247); // CRC code second byte (decimal) put_serial_string ("CRC0"); // The fourth character is a zero put_serial_char (0x0d); CRC1 Enable CRC command checking for Rev E links. This command will return a Rev E WeatherLink to normal operation. This means that CRC check sums ARE required for commands sent to the WeatherLink. Also, ALL data from the WeatherLink includes CRC check sums. If CRC command checking is disabled when you issue this command, you MUST NOT include the CRC code. CRC command checking is only enabled AFTER the command is received. CRC1 command is only available on Rev E Links. put_serial_string ("CRC1"); put_serial_char (0x0d); VII. Command Summary DMP Transfer the contents of the archive memory using the XMODEM CRC protocol. MDMP Dumps an image of Station processor memory to the serial port. This command is only available on the GroWeather, Energy, and Health Links. LOOP 65536-n Send 'n' packets of weather data (sensor image) from the WeatherLink. RRD bank address n-1 Read 'n' (1-8) nibbles from the link memory from 'address' in 'bank'. RWR bank | n-1 address data Write 'n' (1-8) nibbles of 'data' into the link memory at 'address' in 'bank.' SRD address n-1 Read 'n' bytes of archive memory beginning at 'address.' Both 'address' and 'n-1' are 16 bit numbers. SWR address data Write 'data' (one byte) to 'address' (2 bytes) in archive memory. WRD n | bank address Read 'n' (1-8) nibbles of data from the station memory starting at 'address' For a bank 0 use 'bank' = 2, for a bank 1 use 'bank' = 4. WWR n | bank address data Write 'n' (1-8) nibbles of data to the station memory starting at 'address' For bank 0 use 'bank' = 1, for bank 1 use 'bank' = 3. SAP n Set the archive interval to 'n' minutes. 'n' is one byte. SSP 256-n Set the time interval between samples of the sensor image to 'n' seconds. 'n' is one byte. The maximum number of samples in an interval is 255. STOP Tell the WeatherLink to stop updating the sensor image and archiving. START Tell the WeatherLink to begin updating the sensor image and archiving data. This command is only needed if you have previously sent a stop command. ARC Force a write to archive memory. IMG Force a sampling of the sensor image. DBT Disable the archive timer. EBT Enable the archive timer. CRC0 Disable CRC command checking for Rev E links. CRC1 Enable CRC command checking for Rev E links. VIII. Illustrated Examples A. Reading Calibrated Data Most of the data values displayed on the Station's LCD have been calibrated. The term "calibrated" here means a user supplied offset has been added to the "raw" number read by the weather station. The data stored in "XxxxDta" memory locations (i.e. Tp1Dta, SpdDta, etc. See Section IX) are uncalibrated. This goes for LOOP data, and archived data as well. Thus, you may have to calibrate the data you read off the station (or link). You should take the time to read the station's user manual to familiarize yourself with some of the Cal number basics. There are several approaches to how to implement Cal numbers. 1: Your program takes input from the user and records the Cal numbers in a configuration file on the PC. Optionally the program could set the station's Cal numbers at the same time so they agree. 2. Or, the user could set the Cal number on the station (either manually or with another program) and your program reads the required Cal numbers off the station. Always check sensor values for invalid data BEFORE applying calibration numbers. Do not apply a calibration number to an invalid data value. See "Invalid Data values" below for more information. The rest of this section will explain how to use the second approach. The following Cal Numbers are explained: 1 Temperature, 2 Humidity, 3 Barometer, 4 Rain, 5 Wind Speed, 6 Rain Rate, and 7 UV MED's. 1. Temperature CAL Each of the two temperature sensors has a separate Cal number. Only the current station data and all Link data--including the sensor image (LOOP) and archived data--needs to be calibrated. Hi/Low data on the station and "derived" data (i.e. Dewpoint, Wind chill, and THI) already have the Cal number taken into account. The value at the Cal number location is an offset (in Degrees F*10) to be added to the data. Note: this value is a signed data value. Reading Inside Temp on the Monitor (or Wizard or Perception): put_serial_string ("WRD"); // Send read command. put_serial_char (0x44); // read 4 nibbles from bank 1. put_serial_char (0x52); // Read beginning at 52h. // (Inside Temp Cal on Monitor) put_serial_char (0x0D); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(2); // get the returned data (in bytes) InTempCAL = *((int *) receive_buffer) // read the Cal number out of the buffer put_serial_string ("WRD"); // Send read command. put_serial_char (0x44); // read 4 nibbles from bank 1. put_serial_char (0x30); // Read beginning at 30h. // (Inside Temp Data on Monitor) put_serial_char (0xd); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(2); // get the returned data (in bytes) InTemp = *((int *) receive_buffer) // read the Raw Temperature out of the buffer // Verify that the Raw Temperature is not an invalid data value before // applying the cal number. See "Invalid Data values" below for // more information. InTemp = InTemp + InTempCal // InTemp is now Calibrated Reading Outside Temp on the Energy Station: put_serial_string ("WRD"); // Send read command. put_serial_char (0x34); // read 3 nibbles from bank 1. put_serial_char (0x45); // Read beginning at 45h. // (Outside Temp Cal on Energy) put_serial_char (0xd); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(2); // get the returned data (in bytes) // Note that the upper nibble of the last byte will be set // to 0 Also, even though the address was odd, the nibbles // are aligned so that the addressed nibble is the least // significant nibble of the first byte OutTempCAL = *((int *) receive_buffer) // read the Cal number out of the buffer if(OutTempCAL > 2048) // Check for negative numbers { OutTempCAL = OutTempCAL - 4096; // convert a 3 nibble 2's complement negative // number into a "real" negative number } put_serial_string ("WRD"); // Send read command. put_serial_char (0x34); // read 3 nibbles from bank 1. put_serial_char (0x36); // Read beginning at 36h. // (Outside Temp Data on Energy) put_serial_char (0xd); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(2); // get the returned data (in bytes) OutTemp = *((int *) receive_buffer) // read the Raw Temperature out of the buffer if(OutTemp > 2048) // Check for negative numbers { OutTemp = OutTemp - 4096; // convert a 3 nibble 2's complement negative // number into a "real" negative number } // Verify that the Raw Temperature is not an invalid data value // before applying the cal number. See "Invalid Data values" // below for more information. OutTemp = OutTemp + OutTempCAL // OutTemp is now Calibrated 2. Humidity CAL Only Outside Humidity on the GroWeather, Energy, Health, and on the Monitor Rev C or later have a CAL number. It consists of either a signed 2-byte number (on the Monitor) or a signed 1- byte number (on the other stations) to be added to the current station data and Link data including the sensor image (LOOP) and archived data. Hi/Low and "Derived" values (dewpoint, THI, etc.) already take the Cal number into account. After adding the Cal number to the data, you will need to make sure that the result is in the range 1 to 100. If not, then clip the data at these boundaries. Reading Outside Hum on the Monitor: put_serial_string ("WRD"); // Send read command. put_serial_char (0x44); // read 4 nibbles from bank 1. put_serial_char (0xDA); // Read beginning at DAh. // (Outside Hum Cal on Monitor) put_serial_char (0xd); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(2); // get the returned data (in bytes) OutHumCAL = *((int *) receive_buffer) // read the Cal number out of the buffer put_serial_string ("WRD"); // Send read command. put_serial_char (0x24); // read 2 nibbles from bank 1. put_serial_char (0x98); // Read beginning at 98h. // (Outside Hum Data on Monitor) put_serial_char (0xd); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(1); // get the returned data (in bytes) OutHum = *((unsigned char *) receive_buffer) // read the Raw Humidity out of the buffer if (OutHum == 128) // if the raw sensor value is 128,then either the return HUM_ERROR_VALUE // hum sensor is not working or not attached. OutHum = OutHum + OutHumCal // OutHum is now Calibrated, but possibly out of range if (OutHum >100) OutHum = 100; else if (OutHum < 1) OutHum = 1; // OutHum has been clipped to the range 1 - 100. 3. Barometer The weather station measures the absolute atmospheric pressure. In order to convert this to a Standard Barometric pressure, the station subtracts a calibration offset value. This is determined by having the user enter the desired Barometric reading (derived from some other source i.e. airport, newspaper etc.). The station stores the difference between the desired reading and the actual reading in the "StnDrd" memory register. This calibration number must be subtracted from the current Station data and Link data including the sensor interface (LOOP) and archived data. Note: since at higher elevations the absolute pressure decreases, the barometric pressure is generally larger than the atmospheric pressure and since the calibration number is subtracted from the data, it is generally a negative number. It is 2 bytes long Reading Barometer on the Monitor (or Perception): put_serial_string ("WRD"); // Send read command. put_serial_char (0x44); // read 4 nibbles from bank 1. put_serial_char (0x2C); // Read beginning at 2Ch. // (Barometer Standard on Monitor) put_serial_char (0xd); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(2); // get the returned data (in bytes) BarCAL = *((int *) receive_buffer) // read the Cal number out of the buffer put_serial_string ("WRD"); // Send read command. put_serial_char (0x44); // read 4 nibbles from bank 1. put_serial_char (0x00); // Read beginning at 00h. // (Barometer Data on Monitor) put_serial_char (0xd); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(2); // get the returned data (in bytes) Barometer = *((int *) receive_buffer) // read the Raw Barometer out of the buffer Barometer = Barometer - BarCal // Barometer is now Calibrated 4. Rain Rain data on all stations and links are stored in "unit- less" clicks. The RainCal number tells how many clicks are in an inch of rain. The most common numbers are: 10 for the 0.1" rain collector, 100 for the 0.01" rain collector, and 127 for the 0.2mm rain collector. Reading Yearly Rain on the Monitor (or Wizard): put_serial_string ("WRD"); // Send read command. put_serial_char (0x44); // read 4 nibbles from bank 1. put_serial_char (0xD6); // Read beginning at D6h. // (Rain Cal on Monitor) put_serial_char (0xd); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(2); // get the returned data (in bytes) RainCAL = *((int *) receive_buffer) // read the Cal number out of the buffer put_serial_string ("WRD"); // Send read command. put_serial_char (0x44); // read 4 nibbles from bank 1. put_serial_char (0xCE); // Read beginning at CEh. // (Yearly Rain Data on Monitor) put_serial_char (0xd); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(2); // get the returned data (in bytes) RainClicks = *((int *) receive_buffer) // read the Raw Rain out of the buffer YearRain = (float) RainClicks / (float) RainCal // Make sure this is a floating point calculation // YearRain is now Calibrated in Inches Reading Daily Rain on the GroWeather Station: put_serial_string ("WRD"); // Send read command. put_serial_char (0x44); // read 4 nibbles from bank 1. put_serial_char (0xCF); // Read beginning at CFh. // (Rain Cal on GroWeather) put_serial_char (0xd); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(2); // get the returned data (in bytes) RainCAL = *((int *) receive_buffer) // read the Cal number out of the buffer put_serial_string ("WRD"); // Send read command. put_serial_char (0x34); // read 3 nibbles from bank 1. put_serial_char (0xC9); // Read beginning at C9h. // (Daily Rain Data on GroWeather) put_serial_char (0xd); // Send CR... get_acknowledge(); // verify that the command was received and got ACK fill_buffer(2); // get the returned data (in bytes) // Note that the upper nibble of the last byte will be set // to 0 Also, even though the address was odd, the nibbles // are aligned so that the addressed nibble is the least // significant nibble of the first byte RainClicks = *((int *) receive_buffer) // read the Raw Rain out // of the buffer. Since Rain is unsigned, we do not need to // Check for negative numbers DailyRain = (float) RainClicks / (float) RainCal // Make sure this is a floating point calculation // YearRain is now Calibrated in Inches 5. Wind Speed While all of the stations have a Wind Speed cal number, there are very few situations where it is useful. Primarily if you do not attach a Davis anemometer, or if you are not measuring wind speed. The formula for Wind Speed in MPH is "SpdDta" * 1600 / "SpdCal". Since, the default Cal number is 1600, you can just read "SpdDta" in MPH directly without any further calculation. The Speed Cal only effects the LCD display of the current and Hi wind speed. It is not used in any "Derived" calculations (i.e. Wind Chill, THSWI, or ET). Setting the Cal Number to 3600 will cause the display to be in Hz. That is it will show the number of anemometer revolutions per second. 6. Rain Rate Rain Rate is only available on the GroWeather, Energy, and Health stations. There are two different ways that the Rain Rate data is stored. On the Links (both Sensor Image and archived data), the rate is stored in inches per hour times 10. The current station rain cal is used to calculate this value. See Below. On the Station, the current rain rate (and the Hi rate on the Health station) is stored as "The number of half-seconds between the last rain click and the previous rain click. Given the information above about the station's rain Cal number, the formula for converting raw rate data is: Rate(in/hr) = 7200(1/2 sec/hr) / ("RateDta"(1/2sec/clicks)* "RainCal"(clicks/In)) 7. UV MED's The UV MED's Cal number is designed to allow the UV MED's displays to be adjusted for different skin types. UV Intensity data is stored in tenths of an Index, but can be displayed in both Index and MED's per Hour. UV Doses are stored as "Standard" MED's and always displayed in MED's. The UV MED's Cal number is a number between 1 and 14 which represents a multiplication factor of 0.1 to 1.4. The "Standard" Cal number is 10, representing a multiplication factor of 1.0. The formula for converting UV Index to "Standard" MED's is: UV_MEDs = (3/7) * UV_Index The formula to convert "Standard" MED's to calibrated MED's is: Caled_MEDs = Standard_MEDs * "UVCal" / 10 Note: Make sure that you perform both of the above conversions using floating point arithmetic! B. Using the LOOP command The LOOP command is the preferred way to acquire real time updates of weather data. The data sent in a LOOP packet is the data from the Link's Sensor interface. The pseudo-code description of the link processing loop above describes how often this data is updated from the station. The answer to the question "How often is the data updated?" in the FAQ contains some useful approximate timing figures. LOOP data is also CRC checked (See below for how to implement CRC Checking). Assuming that you want a virtually continuous stream of loop packets, one approach is to ask for a large number (say 1000) of packets in one LOOP command, another approach is to ask for a few packets (5-10) in one LOOP command and repeat the request when they have arrived. In either case there is the possibility that missed characters or other communication difficulties may cause the receiver to become unsynchronized with the link as to where the data packets begin. If this happens you should first stop the stream of LOOP data by sending another valid command (like a read of Link memory). Then clear your receive buffer and send the LOOP command again. Another feature of the LOOP command, only available on the GroWeather, Energy, and Health stations, is the ability to monitor the archiving of data. On these stations, one of the data fields is the "NewPtr" that indicates the SRAM address where the next archive record is to be written. If this number changes during the course of reading LOOP packets, you know that the station has created a new archive record. This feature is used in the "Strip Charts" in the GroWeather, Energy, and Health software to keep the PC database current with the archive memory. The following examples show how to extract data from a data buffer filled with LOOP data. See above for a description of fill_crc_buffer() and see below for how CRC checking is done. Example of reading a Monitor Sensor Image. (reading a Wizard or a Perception is the same only omitting the fields of non- existing sensors). put_serial_string ("LOOP"); send_unsigned ((unsigned) (65535)); // request 1 LOOP packet put_serial_char (0x0d); get_acknowledge(); // verify that the command was received and got ACK header = get_serial_char(); // This should be the block header byte if (header != 1) { error = 1;} // If the header byte is not 1 then there is an error // assuming there is no error ... CRC_Error = fill_crc_buffer(17); // 15 data bytes + 2 CRC bytes. // Header Byte is not included in CRC check // assuming there is no CRC error, the data is stored in recieve_buffer ... inside_temperature = *((int *)(receive_buffer+0)); outside_temperature = *((int *)(receive_buffer+2)); wind_speed = *((unsigned char *)(receive_buffer+4)); wind_direction = *((int *)(receive_buffer+5)); barometer = *((int *)(receive_buffer+7)); inside_humidity = *((unsigned char *)(receive_buffer+9)); outside_humidity = *((unsigned char*)(receive_buffer+10)); rain = *((unsigned *)(receive_buffer+11)); Example of reading a GroWeather sensor image put_serial_string ("LOOP"); send_unsigned ((unsigned) (65535)); // request 1 LOOP packet put_serial_char (0x0d); get_acknowledge(); // verify that the command was received and got ACK header = get_serial_char(); // This should be the block header byte if (header != 1) { error = 1;} // If the header byte is not 1 then there is an error // assuming there is no error ... CRC_Error = fill_crc_buffer(34); // 32 data bytes + 2 CRC bytes. // Header Byte is not included in CRC check // assuming there is no CRC error, the data is stored in receive_buffer ... New_pointer = *((unsigned int *)(receive_buffer)); bar_power_flag = *(( unsigned char *)(receive_buffer+2)); soil_temperature = *((int *)(receive_buffer+3)); air_temperature = *((int *)(receive_buffer+5)); wind_speed = *((unsigned char *)(receive_buffer+7)); wind_dir = *((int *)(receive_buffer+8)); barometer = *((int *)(receive_buffer+10)); rain_rate = *((unsigned char *)(receive_buffer+12)); outside_humidity = *((unsigned char*)(receive_buffer+13)); rain = *((unsigned *)(receive_buffer+14)); solar_rad = *((int *)(receive_buffer+16)); wind_run = *((unsigned char *) (recieve_buffer+18)) + *((unsigned char *) (recieve_buffer+19))*256 + *((unsigned char *) (recieve_buffer+20))*65536 ET = *((unsigned char *) (recieve_buffer+21)) ET_Flags = *((unsigned char *) (recieve_buffer+22)) Deg_Days = *((unsigned char *) (recieve_buffer+23)) + *((unsigned char *) (recieve_buffer+24))*256 + *((unsigned char *) (recieve_buffer+25))*65536 Energy = *((unsigned char *) (recieve_buffer+26)) + *((unsigned char *) (recieve_buffer+27))*256 + *((unsigned char *) (recieve_buffer+28))*65536 Alarm_Flags = *((unsigned char *) (recieve_buffer+29)) + *((unsigned char *) (recieve_buffer+30))*256 + (*((unsigned char *) (recieve_buffer+31)) & 0x0F)*65536 AOM_status = (*((unsigned char *)(recieve_buffer+31)) & 0xF0) >> 4 LeafWetnessData = (*((unsigned char *)(recieve_buffer+32)) & 0xF); LeafWetnessEnabled = (*((unsigned char *)(recieve_buffer+32)) & 0x40) == 0x40; // Check the value of bit 6 C. Using MDMP command While the MDMP command is only available on the GroWeather, Energy, and Health stations, it is very useful any time you want to examine several station memory locations at once. For instance, looking at all the Hi/Lows or all the Alarm thresholds. You could, in principal, use MDMP as an alternative to the LOOP command to provide real time data, but it imposes a greater burden on the Station, Link, and PC processing power and bandwidth. It is therefore not recommend for continuous use. There are 2 difficulties that must be addressed when extracting MDMP data. First, locating the desired data in the data buffer. Second, making sure that the number is sign extended if the value is supposed to be a negative number. Assuming that the MDMP data is stored in a continuous byte sized buffer starting with byte 0, Bank 0 data from the station will be found in Bytes 0-127. Bank 1 data from the station will be found in Bytes 128-255. Remembering that the addresses in the tables below are in nibbles, even addresses are stored in the Least-Significant-Nibble of their corresponding byte, and odd addresses are in the Most-Significant-Nibble. To request and store a memory dump: put_serial_string ("MDMP"); // Request Memory Dump put_serial_char (0x0d); get_acknowledge(); // verify that the command was // received and got ACK CRC_Error = fill_crc_buffer(258); // 256 data bytes + 2 CRC bytes. // receive_buffer has memory dump data. Some examples of reading data out of this buffer: Wind speed on the GroWeather is located at address 0x060 = 96. This corresponds to byte 48 in the buffer. Since the data starts on an even address and is only 2 nibbles long and unsigned, byte 48 is the Wind Speed without any further processing. WindSpeed = receive_buffer(48); Daily ET on the GroWeather is located at address 0x0A7 = 167. This corresponds to the upper nibble of byte 83 in the buffer. Since the data value is 3 nibbles long, the whole of byte 84 is also part of this data field. The data is unsigned so we do not have to worry about sign extension. // Mask and shift nibble 1 nibble1 = (receive_buffer[83] & 0xF0) >> 4; // Add in the upper 2 nibbles DayET = nibble1 + (receive_buffer[84] * 16); Hi Air Temp on the GroWeather is located at address 0x145 = 325 (69 in Bank 1). This corresponds to the upper nibble of byte 162 (128 + 34.5). The data field also includes all of byte 163. After extracting the data, we must check for a negative value. // Mask and shift nibble 1 nibble1 = (receive_buffer[162] & 0xF0) >> 4; // Add in the upper 2 nibbles HiAirTemp = nibble1 + (receive_buffer[163] * 16); // Check the sign bit of a 3-nibble 2's complement number if (HiAirTemp > 2048) HiAirTemp = HiAirTemp - 4096; // If negative, make it so And finally, Soil Temp Low Alarm Threshold on the GroWeather is located at address 0x13C = 316 (60 in Bank 1). This corresponds to byte 158. The data also extends into the lower nibble of byte 159. Again the data needs to be sign extended if necessary // Mask out the Hi nibble nibble3 = (receive_buffer[159] & 0x0F) * 256; // add lower byte to nibble3 SoilLowAlarm = receive_buffer[158] + nibble3; // Check the sign bit of a 3-nibble number if (SoilLowAlarm > 2048) // If negative, make it so SoilLowAlarm = SoilLowAlarm - 4096; D. Invalid Data values In general there are 2 different ways that numerical data is stored on the weather station: Signed and Unsigned. These two methods use different values to indicate that the sensor is not attached (or not working). Signed data can use either the largest positive or smallest negative number that fits into it's data size. Unsigned data uses the largest value. You must keep in mind the size (in nibbles) of the data field you are examine since this will affect the numerical values to be checked for. These Data values are also used in Alarm Thresholds to indicate that no threshold has been set and therefore not to test for that particular alarm condition. Always check sensor values for invalid data BEFORE applying calibration numbers. Do not apply a calibration number to an invalid data value. Rain Rate is a special case dealt with below. Data that accumulates over time (i.e. Rain, ET, Degree-Days, Wind Run, Solar Energy, and UV Dose) is unsigned data. The error value is used only for inactive alarm thresholds. Signed Data Values: Temperature: All temperatures, Hi/Lows, Alarm thresholds, and Cal numbers are Signed data. On the Monitor, the Wizard, and the Perception, these values are stored in 4 nibble fields. Therefore the error values are 0x7FFF = 32767 and 0x8000 = - 32768. On the GroWeather, Energy, and Health stations, these values are stored in 3 nibble fields. And the error values are 0x7FF = 2047 and 0x800 = -2048. Barometer: The current and stored barometer data is stored in 4 nibble fields on all stations. The barometer alarm is stored in 2 nibbles, and uses the value 0x7F = 127 or 0x80 = -128 for invalid data. Wind Direction: On the Monitor, and Wizard stations, the wind direction is stored in a 4 nibble field and uses the values 0x7FFF or 0x8000 to indicate an invalid wind direction. On the GroWeather, Energy, and Health stations, wind direction is stored in a 3 nibble field and uses the values 0x7FF or 0x800 to indicate an invalid wind direction. This information only applies to the current wind direction on the station, or in the sensor image on the link (i.e. LOOP data packet). The data stored in the archive memory is an unsigned byte with the compass direction of the prevailing wind from 0-15. The value 255 is used to indicate that there was either no wind or no wind direction data during the archive period. In addition, the GroWeather, Energy, and Health stations also have 1 nibble fields that record both the current wind direction and the wind direction at the time of the hi wind speed. All 16 values of a 1 nibble number are needed to represent the 16 different compass points. You will need to check the value of the appropriate status bit in order to determine if the data is valid. Humidity: Since valid Humidity values only range from 1% to 100%, it does not make much difference whether humidity is considered a signed or unsigned value. An illegal Humidity reading is represented by the value 0x80 which can either be thought of as 128 or -128 depending upon whether the data is signed or unsigned. The weather station treats the data as signed for the purposes of clearing Hi/Low values. Unsigned Data Values: Wind Speed: Except for Rev A Monitors, and Wizards, wind speed data on all stations is 2 nibbles long and unsigned. On the Rev A Monitors and Wizards, the data is signed. The wind speed hi alarm threshold on all Monitors and Wizards is a 4 nibble signed number using 0x7FFF or 0x8000 to indicate an invalid alarm. On the GroWeather, Energy, and Health stations, the wind speed hi alarm is a 2 nibble unsigned number which uses 0xFF = 255 to indicate an invalid alarm. Note that this means that while the current (and Hi) data can display the value of 255, the alarm can not be set to this value, since that value is used to indicate the absence of a wind speed alarm. Solar Rad: Solar rad is a 3 nibble unsigned number that uses 0xFFF = 4095 to indicate invalid data. UV Intensity: UV Intensity is stored as a 2 nibble unsigned number. The current value, hi value, and hi alarm use the value 0xFF = 255 to indicate invalid data. Rain Rate Data The rain rate data is stored as a 3 nibble unsigned number. Because of the way that rain rate is measured and calculated, larger data values correspond to smaller rain rates. Setting the hi rain rate to zero, for instance, results in an infinite rain rate that is displayed with dashes. These dashes will not go away until the hi rain rate is cleared. When a rain rate value is cleared, it is set to 0xFFF = 4095, the display will read 0.0 inches per hour. In some cases, the station treats this value as a signed number and uses the value 0x7FF = 2047 to indicate a cleared rain rate. E. Calculated Data values Here are some formulas and code examples for how to calculate some of the "Derived" data values found on the station: 1. Wind Chill Wind chill represents how cold the temperature feels in the presence of wind. It is based on the current wind speed (calibration is ignored) and the current outside temperature (calibration is used). The following C code shows how this is done. Note that if the temperature is above 91, the wind has no effect on the wind chill. /* Chill Factor (cf) at 5 MPH intervals */ unsigned char chillTableOne [] = { 156, 151, 146, 141, 133, 123, 11

[2E0PGS]

Is there a command which I can run to see the response of the station before it gets processed by weewx? I tried looking around but didn't find such a debug command. It appears in syslog the humidty is showing 162. I will try locate the exact model of station however from memory it's a Weather Monitor 2 and I didnt recall seeing any other indications without writing down its serial number.

[2E0PGS]

I wonder if I need to adjust the stations calibration manually on the panel or something.

[2E0PGS]

On the front panel it says low humidity is 1% and high is 100% under the recal button. It also says current reading is 65% outside. That is also what weewx is reporting as current. I wonder why its creaping above 100% then.

[2E0PGS]

Oh and thanks for the specification you sent too. I may just have to see if pressing that recal did reset it to 100% or if it already was set to 100% as high. I can't recall how all the interface works since I haven't used it for a while.

[jardiamj]

If you run weewx directly from the command line it will print the packets directly to the screen as they come in. You'll probably see the humidity there going above 100% because that's how it is being parsed by the driver, I will probably need a little more information about your station in order to figure out why it's parsing it that way. I am attaching my Python script where I originally developed the methods for reading the data from the station, it's called wmTest.py, you can use it as follows (I generally use iPython for these sort of debugging): From wmTest import Station my_station = Station('/dev/ttyUSB0') # whatever your stations port is. my_station.open() readings = my_station.get_readings() data = my_station.parse_readings(readings) print(data) The variable [readings] will hold the packet returned by the station for our sent LOOP command and for the Weather Monitor II stations it has the following structure: 1 byte = header ---> 0x01 (checked and removed by get_readings) 2 bytes = inTemp 2 bytes = outTemp 1 byte = windSpeed 2 bytes = windDir 2 bytes = pressure 1 byte = inHumidity 1 byte = outHumidity 2 bytes = rain_total 2 bytes = not_used 2 bytes = CRC_checksum Notice that they are all in little-endian byte packs, so the parse_readings() function unpacks it using python's struct.unpack module. You could do the same with the [readings] variable like this: buf = struct.unpack('<hhBhhBBhhh', readings) The header byte gets removed from the packet by the get_readings function so the struct.unpack starts with the inTemp data, your variable [buf] will be a list of the data in the described order. If you can send me what that looks like with the corresponding data on the screen of you Weather Station we might be able to figure out what's going on. Thanks, Jardi.

…

On Sun, Mar 24, 2019, 11:39 AM Peter Stevenson ***@***.***> wrote: Oh and thanks for the specification you sent too. I may just have to see if pressing that recal did reset it to 100% or if it already was set to 100% as high. I can't recall how all the interface works since I haven't used it for a while. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#1 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABCc3CR-BNOiCPf9zAa2tu_xrKp2yZY2ks5vZ8Z7gaJpZM4b4a0g> .

[jardiamj]

Also. Can you open a new issue? since all this is unrelated to the original one.