CryoSkills Datalogger - Libraries

This repository contains libraries for the CryoSkills datalogger which are described below.

For the most part, these libraries provide 'wrapping' functions around existing functionality to make the firmware easier to follow.

Library - cryo_system

The cryo_system library implements debugging and error functionality for the CryoSkills datalogger.

Debug Messages

Modifying the CRYO_DEBUG level in the datalogger firmware sets whether debug messages (sent using CRYO_DEBUG_MESSAGE) are disabled, written to the USB Debug port and/or written to the SD card.

Debug Mode	Description
DISABLED	Debug messages disabled.
DEBUG_SERIAL	Debug messages forwarded to the USB debug port.
DEBUG_SD	Debug messages written to DEBUG.TXT on the SD card.
DEBUG_SERIAL_AND_SD	Debug messages forward to USB debug port and written to SD card.

You can implement additional debug messages in the code using the CRYO_DEBUG_MESSAGE function as below:

CRYO_DEBUG_MESSAGE("Something happened!");

Error Messages

The cyro_error function is used to help identify the cause of crashes in the firmware by blinking a 'morse-style' binary code. All error messages are 8-bits long and consist of ;longer blinks of 400ms (corresponding to a binary 1) and shorter blinks (corresponding to a binary 0).

Currently implemented error codes are listed below, however custom error codes can be added by calling cryo_error with the appropriate numeric value.

Error Code	Value	Description
CRYO_ERROR_RADIO_INIT	0b10000000	The radio module has failed to initialise - is the datalogger board powered (and not just the Adalogger)?
CRYO_ERROR_DS18B20_INIT	0b01000000	No DS18B20 sensor could be found.
CRYO_ERROR_SD_INIT	0b00100000	The SD card failed to initialise - is there an SD card present? Is it formatted to FAT32?
CRYO_ERROR_INA3221_INIT	0b00010000	The INA3221 module failed to initialise - is the datalogger board powered (and not just the Adalogger)?

Library - cryo_sleep

The cryo_sleep library keeps track of the time (using the integrated real-time clock) and conserves power by setting the microcontroller to a low-power sleep module between measurements.

The software pattern for programs using the cryo_sleep library is shown below

#include "cryo_sleep.h"

void my_function();

void setup() {
    // Do setup activities
    SerialDebug.begin(9600);
    // ...

    // Configure the real-time clock
    cryo_configure_clock(__DATE__, __TIME__);
    
    // Configure a function to be called every 30 seconds 
    cryo_add_alarm_every(30, my_function);
}

void loop() {
    // Wakeup and reconfigure the clock speed
    cryo_wakeup();
    // Run any functions that need to be called
    cryo_raise_alarms();
    // Go back to sleep!
    cryo_sleep();
}

void my_function() {
    SerialDebug.println("Hello, world!");
}

Library - cryo_adc

The cryo_adc library configures the analogue-to-digital converter (ADC) in the SAMD21 microcontroller to be used in its 'differential input' mode. This allows for improved sensitivity and precision when using the PT1000 temperature sensor through gain and averaging.

Library - cryo_radio

The cryo_radio library controls the RFM96W radio module on the datalogger PCB to send temperature data and housekeeping information on a 433 MHz LoRa radio link.

Library - cryo_power

The cryo_power library uses the integrated INA3221 power meter on the datalogger PCB to give us information about the power consumption of different components of the sensor kit (solar panel, battery, circuit board). This is useful for debugging and monitoring the battery level.

Requirements

The CryoSkills datalogger libraries depend on the following third-party libraries:

Library Name	Description	URL
CryoSkills	Auxiliary libraries for the CryoSkills datalogger	https://github.com/cryoskills/sensor-kit-libraries
INA3221	CryoSkills modification of INA3221 library	https://github.com/cryoskills/INA3221
ZeroPowerManager	Required to compile CryoSkills library	https://github.com/ee-quipment/ZeroPowerManager
RadioHead	Required to control the RFM96W radio module	https://github.com/PaulStoffregen/RadioHead/