Fix farenheit conversion

[mfalkvidd]

When temperature in C was below 0, the conversion to F was wrong due to
treating the C value as unsigned integer instead of signed integer.

See http://bit.ly/3ckRfxp for more information.

Thanks to hoggin for reporting this problem.

[Yveaux]

Nice catch! You could also use auto instead of int or include it in the return statement to leave the type up to the compiler

[my-bam]

Hi. This isn't working for me. Any ideas?

[mfalkvidd]

@my-bam could you be a bit more specific?

What version of MySensors are you using?
What result did you expect?
Can you post your sketch and the debug output?

[my-bam]

1. VER=2.3.2
2. Temp 128.86C Hum 118.99
   3.1.-------------------------------------------------------------------------------

/**
 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 *
 * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2015 Sensnology AB
 * Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 *******************************
 *
 * REVISION HISTORY
 * Version 1.0: Yveaux
 * 
 * DESCRIPTION
 * This sketch provides an example of how to implement a humidity/temperature
 * sensor using a Si7021 sensor.
 *  
 * For more information, please visit:
 * http://www.mysensors.org/build/humiditySi7021
 * 
 */

// Enable debug prints
#define MY_DEBUG

// Enable REPORT_BATTERY_LEVEL to measure battery level and send changes to gateway
#define REPORT_BATTERY_LEVEL

// Enable and select radio type attached 
#define MY_RADIO_RF24
//#define MY_RADIO_RFM69
//#define MY_RS485

#include <MySensors.h>  
#include <DallasTemperature.h>
#include <OneWire.h>

#define CHILD_ID_HUM  0
#define CHILD_ID_TEMP 1

//#define COMPARE_TEMP 1 // Send temperature only if changed? 1 = Yes 0 = No

#define ONE_WIRE_BUS 3 // Pin where dallase sensor is connected 
#define MAX_ATTACHED_DS18B20 16
unsigned long SLEEP_TIME = 30000; // Sleep time between reads (in milliseconds)
OneWire oneWire(ONE_WIRE_BUS); // Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
DallasTemperature sensors(&oneWire); // Pass the oneWire reference to Dallas Temperature. 
float lastTemperature[MAX_ATTACHED_DS18B20];
int numSensors=0;
bool receivedConfig = false;
MyMessage msg(0,V_TEMP);

static bool metric = true;

// Sleep time between sensor updates (in milliseconds)
static const uint64_t UPDATE_INTERVAL = 10000;

#include <SI7021.h>
static SI7021 sensor;

#ifdef REPORT_BATTERY_LEVEL
#include <Vcc.h>
static uint8_t oldBatteryPcnt = 200;  // Initialize to 200 to assure first time value will be sent.
const float VccMin        = 1.8;      // Minimum expected Vcc level, in Volts: Brownout at 1.8V    -> 0%
//const float VccMax        = 2.0*1.6;  // Maximum expected Vcc level, in Volts: 2xAA fresh Alkaline -> 100%
const float VccMax        = 3.0;  // Maximum expected Vcc level, in Volts: 2xAA fresh Alkaline -> 100%
const float VccCorrection = 1.0;      // Measured Vcc by multimeter divided by reported Vcc
static Vcc vcc(VccCorrection); 
#endif

void before()
{
  // Startup up the OneWire library
  sensors.begin();
}

void presentation()  
{ 
  // Send the sketch info to the gateway
  sendSketchInfo("Sensor s101", "1.0");

  // Present sensors as children to gateway
  present(CHILD_ID_HUM, S_HUM,   "Humidity");
  present(CHILD_ID_TEMP, S_TEMP, "Temperature");

  numSensors = sensors.getDeviceCount();

  // Present all sensors to controller
  for (int i=2; i<(2+numSensors) && i<MAX_ATTACHED_DS18B20; i++) {   
     present(i, S_TEMP, "DS18B20");
  }

  metric = getControllerConfig().isMetric;
}

void setup()
{
  while (not sensor.begin())
  {
    Serial.println(F("Sensor not detected!"));
    delay(5000);
  }
  // requestTemperatures() will not block current thread
  sensors.setWaitForConversion(false);  
}


void loop()      
{  
  // Read temperature & humidity from sensor.
  const float temperature = float( metric ? sensor.getCelsiusHundredths() : sensor.getFahrenheitHundredths() ) / 100.0;
  const float humidity    = float( sensor.getHumidityBasisPoints() ) / 100.0;

#ifdef MY_DEBUG
  Serial.print(F("Temp "));
  Serial.print(temperature);
  Serial.print(metric ? 'C' : 'F');
  Serial.print(F("\tHum "));
  Serial.println(humidity);
#endif

  static MyMessage msgHum( CHILD_ID_HUM,  V_HUM );
  static MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP);

  send(msgTemp.set(temperature, 2));
  send(msgHum.set(humidity, 2));

  sensors.requestTemperatures();

  // query conversion time and sleep until conversion completed
  int16_t conversionTime = sensors.millisToWaitForConversion(sensors.getResolution());
  // sleep() call can be replaced by wait() call if node need to process incoming messages (or if node is repeater)
  sleep(conversionTime);

  // Read temperatures and send them to controller 
  for (int i=0; i<numSensors && i<MAX_ATTACHED_DS18B20; i++) {
 
    // Fetch and round temperature to one decimal
    float temperature_dallas = static_cast<float>(static_cast<int>((getControllerConfig().isMetric?sensors.getTempCByIndex(i):sensors.getTempFByIndex(i)) * 10.)) / 10.;
 
    // Only send data if temperature has changed and no error
    #if COMPARE_TEMP == 1
    if (lastTemperature[i] != temperature_dallas && temperature_dallas != -127.00 && temperature_dallas != 85.00) {
    #else
    if (temperature_dallas != -127.00 && temperature_dallas != 85.00) {
    #endif
 

      // Send in the new temperature
      send(msg.setSensor(i+2).set(temperature_dallas,1));
      // Save new temperatures for next compare
      lastTemperature[i]=temperature_dallas;
    }
  }

#ifdef REPORT_BATTERY_LEVEL
  const uint8_t batteryPcnt = static_cast<uint8_t>(0.5 + vcc.Read_Perc(VccMin, VccMax));

#ifdef MY_DEBUG
  Serial.print(F("Vbat "));
  Serial.print(vcc.Read_Volts());
  Serial.print(F("\tPerc "));
  Serial.println(batteryPcnt);
#endif

  // Battery readout should only go down. So report only when new value is smaller than previous one.
  if ( batteryPcnt < oldBatteryPcnt )
  {
      sendBatteryLevel(batteryPcnt);
      oldBatteryPcnt = batteryPcnt;
  }
#endif

  // Sleep until next update to save energy
  sleep(UPDATE_INTERVAL); 
}

3.2.----------------------------------------------------------------------------------------------

16 MCO:BGN:INIT NODE,CP=RNNNA---,FQ=8,REL=255,VER=2.3.2
28 MCO:BGN:BFR
65 TSM:INIT
65 TSF:WUR:MS=0
73 TSM:INIT:TSP OK
75 TSF:SID:OK,ID=101
77 TSM:FPAR
81 ?TSF:MSG:SEND,101-101-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
866 TSF:MSG:READ,0-0-101,s=255,c=3,t=8,pt=1,l=1,sg=0:0
872 TSF:MSG:FPAR OK,ID=0,D=1
2091 TSM:FPAR:OK
2091 TSM:ID
2093 TSM:ID:OK
2095 TSM:UPL
2099 TSF:MSG:SEND,101-101-0-0,s=255,c=3,t=24,pt=1,l=1,sg=0,ft=0,st=OK:1
2107 TSF:MSG:READ,0-0-101,s=255,c=3,t=25,pt=1,l=1,sg=0:1
2113 TSF:MSG:PONG RECV,HP=1
2115 TSM:UPL:OK
2117 TSM:READY:ID=101,PAR=0,DIS=1
2123 TSF:MSG:SEND,101-101-0-0,s=255,c=3,t=15,pt=6,l=2,sg=0,ft=0,st=OK:0100
2131 TSF:MSG:READ,0-0-101,s=255,c=3,t=15,pt=6,l=2,sg=0:0100
2140 TSF:MSG:SEND,101-101-0-0,s=255,c=0,t=17,pt=0,l=5,sg=0,ft=0,st=OK:2.3.2
2150 TSF:MSG:SEND,101-101-0-0,s=255,c=3,t=6,pt=1,l=1,sg=0,ft=0,st=OK:0
4161 TSF:MSG:SEND,101-101-0-0,s=255,c=3,t=11,pt=0,l=11,sg=0,ft=0,st=OK:Sensor s101
4171 TSF:MSG:SEND,101-101-0-0,s=255,c=3,t=12,pt=0,l=3,sg=0,ft=0,st=OK:1.0
4182 TSF:MSG:SEND,101-101-0-0,s=0,c=0,t=7,pt=0,l=8,sg=0,ft=0,st=OK:Humidity
4196 TSF:MSG:SEND,101-101-0-0,s=1,c=0,t=6,pt=0,l=11,sg=0,ft=0,st=OK:Temperature
4208 TSF:MSG:SEND,101-101-0-0,s=2,c=0,t=6,pt=0,l=7,sg=0,ft=0,st=OK:DS18B20
4216 MCO:REG:REQ
4220 TSF:MSG:SEND,101-101-0-0,s=255,c=3,t=26,pt=1,l=1,sg=0,ft=0,st=OK:2
4229 TSF:MSG:READ,0-0-101,s=255,c=3,t=27,pt=1,l=1,sg=0:1
4235 MCO:PIM:NODE REG=1
4237 MCO:BGN:STP
4239 MCO:BGN:INIT OK,TSP=1
Temp 128.86C Hum 118.99
4247 TSF:MSG:SEND,101-101-0-0,s=1,c=1,t=0,pt=7,l=5,sg=0,ft=0,st=OK:128.86
4257 TSF:MSG:SEND,101-101-0-0,s=0,c=1,t=1,pt=7,l=5,sg=0,ft=0,st=OK:118.99
4268 MCO:SLP:MS=750,SMS=0,I1=255,M1=255,I2=255,M2=255
4274 TSF:TDI:TSL
4278 MCO:SLP:WUP=-1
4280 TSF:TRI:TSB
4315 TSF:MSG:SEND,101-101-0-0,s=2,c=1,t=0,pt=7,l=5,sg=0,ft=0,st=OK:26.3
Vbat 3.35 Perc 100
4327 TSF:MSG:SEND,101-101-0-0,s=255,c=3,t=0,pt=1,l=1,sg=0,ft=0,st=OK:100
4335 MCO:SLP:MS=10000,SMS=0,I1=255,M1=255,I2=255,M2=255
4341 TSF:TDI:TSL
4343 MCO:SLP:WUP=-1
4345 TSF:TRI:TSB
Temp 128.86CHum 118.99