generic_data_logger

A generic approach to using data loggers to store sensor data. It supports also status and error output over led blinking patterns.

The program retrieves data at a specified interval from attached sensors (sensor initialisation and data retrieval has to be added to arduino-generic-data-logger.ino). This data gets written to an attached sd card data logger.

I can now claim, that this sketch works reliably on a high altitude balloon in > 30,000 m height at around -20 degrees Celsius :).

LED Debugging

Also you can add an led (pin is specified in src/led.cpp), on which debugging information will be shown in form of blinking patterns.

To display one of those patterns you can call

executePattern(int length, unsigned long int pattern);

from src/led.h. The pattern is specified as a bitsequence, the length parameter specifies the number of bits to be included in that bitsequence.

So for example calling

executePattern(8, 0b11001010);

would make the LED flash for two base intervals (base interval is specified in led.h), then wait for two intervals and then blink twice for one base interval.

Signals

The predefined signals include

• SETUP_COMPLETE, which is called if the setup completed successfully (LED-Pattern 0b101010001010)
• IN_LOOP, which is called at the start of every loop cycle (LED-Pattern 0b101000)
• DATA_COMPLETE, which is called if the data retrieved from the sensors complies with certain validity checks (which have to be implemented) (LED-Pattern 0b111010)
• WRITE_COMPLETE, which is called if the write to the SD-Card was successful (LED-Pattern 0b100101010100)

These patterns are defined in src/signals.cpp.

You can call a signal with function

signal(Signal);

Errors

The predefined errors include

• NO_ERROR, no led pattern
• ERR_SETUP_FAILED, called, if setup fails (LED-Pattern 0b11001010001010)
• ERR_DATA_CORRUPT, called if data fails in data integrity checks (LED-Pattern, 0b1100101000101010)
• ERR_DATA_WRITE_FAILED, called, if write to SD card failed, (LED-Pattern 0b11001010001010111010)
• ERR_INVALID_SIGNAL, called, if signal-function is called with invalid signal code (LED-Pattern 0b110010100011101110)
• ERR_INVALID_ERROR_CODE, called, if error-function is called with invalid error code (LED-Pattern 0b1100101000111011101110)

These patterns are defined in src/error.cpp.

There is a certain error prefix for every error code for making it easier spotting them: 0b1100101000. This pattern is present for all error codes, following an individual pattern each code.

You can call an error with function

error(ErrorCode);