Sending data to ThingSpeak

Unique Features of the ThingSpeak Example

• A single logger publishes data to ThingSpeak.
• Uses an Espressif ESP8266 to publish data.

To Use this Example

const char *thingSpeakMQTTKey = "XXXXXXXXXXXXXXXX";  // Your MQTT API Key from Account > MyProfile.
const char *thingSpeakChannelID = "######";  // The numeric channel id for your channel
const char *thingSpeakChannelKey = "XXXXXXXXXXXXXXXX";  // The Write API Key for your channel

PlatformIO Configuration

; PlatformIO Project Configuration File
;
;   Build options: build flags, source filter
;   Upload options: custom upload port, speed and extra flags
;   Library options: dependencies, extra library storages
;   Advanced options: extra scripting
;
; Please visit documentation for the other options and examples
; http://docs.platformio.org/page/projectconf.html

[platformio]
description = ModularSensors example sending data to ThingSpeak

[env:mayfly]
monitor_speed = 115200
board = mayfly
platform = atmelavr
framework = arduino
lib_ldf_mode = deep+
lib_ignore =
    RTCZero
    Adafruit NeoPixel
    Adafruit GFX Library
    Adafruit SSD1306
    Adafruit ADXL343
    Adafruit STMPE610
    Adafruit TouchScreen
    Adafruit ILI9341
build_flags =
    -DSDI12_EXTERNAL_PCINT
    -DNEOSWSERIAL_EXTERNAL_PCINT
    -DMQTT_MAX_PACKET_SIZE=240
    -DTINY_GSM_RX_BUFFER=64
    -DTINY_GSM_YIELD_MS=2
lib_deps =
    envirodiy/EnviroDIY_ModularSensors
;  ^^ Use this when working from an official release of the library
;    https://github.com/EnviroDIY/ModularSensors.git#develop
;  ^^ Use this when if you want to pull from the develop branch

The Complete Code

/** =========================================================================
 * @file logging_to_ThingSpeak.ino
 * @brief Example logging data and publishing to ThingSpeak.
 *
 * @author Sara Geleskie Damiano <sdamiano@stroudcenter.org>
 * @copyright (c) 2017-2022 Stroud Water Research Center (SWRC)
 *                          and the EnviroDIY Development Team
 *            This example is published under the BSD-3 license.
 *
 * Build Environment: Visual Studios Code with PlatformIO
 * Hardware Platform: EnviroDIY Mayfly Arduino Datalogger
 *
 * DISCLAIMER:
 * THIS CODE IS PROVIDED "AS IS" - NO WARRANTY IS GIVEN.
 * ======================================================================= */

// ==========================================================================
//  Defines for TinyGSM
// ==========================================================================
/** Start [defines] */
#ifndef TINY_GSM_RX_BUFFER
#define TINY_GSM_RX_BUFFER 64
#endif
#ifndef TINY_GSM_YIELD_MS
#define TINY_GSM_YIELD_MS 2
#endif
#ifndef MQTT_MAX_PACKET_SIZE
#define MQTT_MAX_PACKET_SIZE 240
#endif
/** End [defines] */

// ==========================================================================
//  Include the libraries required for any data logger
// ==========================================================================
/** Start [includes] */
// The Arduino library is needed for every Arduino program.
#include <Arduino.h>

// EnableInterrupt is used by ModularSensors for external and pin change
// interrupts and must be explicitly included in the main program.
#include <EnableInterrupt.h>

// Include the main header for ModularSensors
#include <ModularSensors.h>
/** End [includes] */


// ==========================================================================
//  Data Logging Options
// ==========================================================================
/** Start [logging_options] */
// The name of this program file
const char* sketchName = "logging_to_ThingSpeak.ino";
// Logger ID, also becomes the prefix for the name of the data file on SD card
const char* LoggerID = "XXXXX";
// How frequently (in minutes) to log data
const uint8_t loggingInterval = 15;
// Your logger's timezone.
const int8_t timeZone = -5;  // Eastern Standard Time
// NOTE:  Daylight savings time will not be applied!  Please use standard time!

// Set the input and output pins for the logger
// NOTE:  Use -1 for pins that do not apply
const int32_t serialBaud = 115200;  // Baud rate for debugging
const int8_t  greenLED   = 8;       // Pin for the green LED
const int8_t  redLED     = 9;       // Pin for the red LED
const int8_t  buttonPin  = 21;      // Pin for debugging mode (ie, button pin)
const int8_t  wakePin    = 31;  // MCU interrupt/alarm pin to wake from sleep
// Mayfly 0.x D31 = A7
// Set the wake pin to -1 if you do not want the main processor to sleep.
// In a SAMD system where you are using the built-in rtc, set wakePin to 1
const int8_t sdCardPwrPin   = -1;  // MCU SD card power pin
const int8_t sdCardSSPin    = 12;  // SD card chip select/slave select pin
const int8_t sensorPowerPin = 22;  // MCU pin controlling main sensor power
/** End [logging_options] */


// ==========================================================================
//  Wifi/Cellular Modem Options
// ==========================================================================
/** Start [espressif_esp8266] */
// For almost anything based on the Espressif ESP8266 using the AT command
// firmware
#include <modems/EspressifESP8266.h>
// Create a reference to the serial port for the modem
HardwareSerial& modemSerial = Serial1;  // Use hardware serial if possible
const int32_t   modemBaud   = 115200;   // Communication speed of the modem
// NOTE:  This baud rate too fast for an 8MHz board, like the Mayfly!  The
// module should be programmed to a slower baud rate or set to auto-baud using
// the AT+UART_CUR or AT+UART_DEF command.

// Modem Pins - Describe the physical pin connection of your modem to your board
// NOTE:  Use -1 for pins that do not apply
const int8_t modemVccPin   = -2;  // MCU pin controlling modem power
const int8_t modemResetPin = 20;  // MCU pin connected to modem reset pin
const int8_t modemLEDPin =
    redLED;  // MCU pin connected an LED to show modem status

// Network connection information
const char* wifiId  = "xxxxx";  // The WiFi access point
const char* wifiPwd = "xxxxx";  // The password for connecting to WiFi

// Create the loggerModem object
EspressifESP8266 modemESP(&modemSerial, modemVccPin, modemResetPin, wifiId,
                          wifiPwd);
// Create an extra reference to the modem by a generic name
EspressifESP8266 modem = modemESP;
/** End [espressif_esp8266] */


// ==========================================================================
//  Using the Processor as a Sensor
// ==========================================================================
/** Start [processor_sensor] */
#include <sensors/ProcessorStats.h>

// Create the main processor chip "sensor" - for general metadata
const char*    mcuBoardVersion = "v1.1";
ProcessorStats mcuBoard(mcuBoardVersion);
/** End [processor_sensor] */


// ==========================================================================
//  Maxim DS3231 RTC (Real Time Clock)
// ==========================================================================
/** Start [ds3231] */
#include <sensors/MaximDS3231.h>

// Create a DS3231 sensor object
MaximDS3231 ds3231(1);
/** End [ds3231] */


// ==========================================================================
//  Campbell OBS 3 / OBS 3+ Analog Turbidity Sensor
// ==========================================================================
/** Start [obs3] */
#include <sensors/CampbellOBS3.h>

const int8_t  OBS3Power = sensorPowerPin;  // Power pin (-1 if unconnected)
const uint8_t OBS3NumberReadings = 10;
const uint8_t ADSi2c_addr        = 0x48;  // The I2C address of the ADS1115 ADC
// Campbell OBS 3+ *Low* Range Calibration in Volts
const int8_t OBSLowADSChannel = 0;  // ADS channel for *low* range output
const float  OBSLow_A         = 0.000E+00;  // "A" value (X^2) [*low* range]
const float  OBSLow_B         = 1.000E+00;  // "B" value (X) [*low* range]
const float  OBSLow_C         = 0.000E+00;  // "C" value [*low* range]

// Create a Campbell OBS3+ *low* range sensor object
CampbellOBS3 osb3low(OBS3Power, OBSLowADSChannel, OBSLow_A, OBSLow_B, OBSLow_C,
                     ADSi2c_addr, OBS3NumberReadings);


// Campbell OBS 3+ *High* Range Calibration in Volts
const int8_t OBSHighADSChannel = 1;  // ADS channel for *high* range output
const float  OBSHigh_A         = 0.000E+00;  // "A" value (X^2) [*high* range]
const float  OBSHigh_B         = 1.000E+00;  // "B" value (X) [*high* range]
const float  OBSHigh_C         = 0.000E+00;  // "C" value [*high* range]

// Create a Campbell OBS3+ *high* range sensor object
CampbellOBS3 osb3high(OBS3Power, OBSHighADSChannel, OBSHigh_A, OBSHigh_B,
                      OBSHigh_C, ADSi2c_addr, OBS3NumberReadings);
/** End [obs3] */


// ==========================================================================
//  Meter Hydros 21 Conductivity, Temperature, and Depth Sensor
// ==========================================================================
/** Start [hydros21] */
#include <sensors/MeterHydros21.h>

const char*   hydrosSDI12address = "1";  // The SDI-12 Address of the Hydros 21
const uint8_t hydrosNumberReadings = 6;  // The number of readings to average
const int8_t  SDI12Power = sensorPowerPin;  // Power pin (-1 if unconnected)
const int8_t  SDI12Data  = 7;               // The SDI12 data pin

// Create a Meter Hydros 21 sensor object
MeterHydros21 hydros21(*hydrosSDI12address, SDI12Power, SDI12Data,
                       hydrosNumberReadings);
/** End [hydros21] */


// ==========================================================================
//  Creating the Variable Array[s] and Filling with Variable Objects
// ==========================================================================
/** Start [variable_arrays] */
Variable* variableList[] = {
    new MeterHydros21_Cond(&hydros21, "12345678-abcd-1234-ef00-1234567890ab"),
    new MeterHydros21_Temp(&hydros21, "12345678-abcd-1234-ef00-1234567890ab"),
    new MeterHydros21_Depth(&hydros21, "12345678-abcd-1234-ef00-1234567890ab"),
    new CampbellOBS3_Turbidity(&osb3low, "12345678-abcd-1234-ef00-1234567890ab",
                               "TurbLow"),
    new CampbellOBS3_Turbidity(
        &osb3high, "12345678-abcd-1234-ef00-1234567890ab", "TurbHigh"),
    new ProcessorStats_Battery(&mcuBoard,
                               "12345678-abcd-1234-ef00-1234567890ab"),
    new MaximDS3231_Temp(&ds3231, "12345678-abcd-1234-ef00-1234567890ab"),
    new Modem_RSSI(&modem, "12345678-abcd-1234-ef00-1234567890ab")};
// Count up the number of pointers in the array
int variableCount = sizeof(variableList) / sizeof(variableList[0]);

// Create the VariableArray object
VariableArray varArray;
/** End [variable_arrays] */


// ==========================================================================
//  The Logger Object[s]
// ==========================================================================
/** Start [loggers] */
// Create a logger instance
Logger dataLogger;
/** End [loggers] */


// ==========================================================================
//  Creating Data Publisher[s]
// ==========================================================================
// Create a channel with fields on ThingSpeak in advance
// The fields will be sent in exactly the order they are in the variable array.
// Any custom name or identifier given to the field on ThingSpeak is irrelevant.
// No more than 8 fields of data can go to any one channel.  Any fields beyond
// the eighth in the array will be ignored.
const char* thingSpeakMQTTKey =
    "XXXXXXXXXXXXXXXX";  // Your MQTT API Key from Account > MyProfile.
const char* thingSpeakChannelID =
    "######";  // The numeric channel id for your channel
const char* thingSpeakChannelKey =
    "XXXXXXXXXXXXXXXX";  // The Write API Key for your channel

// Create a data publisher for ThingSpeak
#include <publishers/ThingSpeakPublisher.h>
ThingSpeakPublisher TsMqtt;
/** End [loggers] */


// ==========================================================================
//  Working Functions
// ==========================================================================
/** Start [working_functions] */
// Flashes the LED's on the primary board
void greenredflash(uint8_t numFlash = 4, uint8_t rate = 75) {
    for (uint8_t i = 0; i < numFlash; i++) {
        digitalWrite(greenLED, HIGH);
        digitalWrite(redLED, LOW);
        delay(rate);
        digitalWrite(greenLED, LOW);
        digitalWrite(redLED, HIGH);
        delay(rate);
    }
    digitalWrite(redLED, LOW);
}

// Reads the battery voltage
// NOTE: This will actually return the battery level from the previous update!
float getBatteryVoltage() {
    if (mcuBoard.sensorValues[0] == -9999) mcuBoard.update();
    return mcuBoard.sensorValues[0];
}
/** End [working_functions] */


// ==========================================================================
//  Arduino Setup Function
// ==========================================================================
/** Start [setup] */
void setup() {
    // Start the primary serial connection
    Serial.begin(serialBaud);

    // Print a start-up note to the first serial port
    Serial.print(F("Now running "));
    Serial.print(sketchName);
    Serial.print(F(" on Logger "));
    Serial.println(LoggerID);
    Serial.println();

    Serial.print(F("Using ModularSensors Library version "));
    Serial.println(MODULAR_SENSORS_VERSION);
    Serial.print(F("TinyGSM Library version "));
    Serial.println(TINYGSM_VERSION);
    Serial.println();

    // Start the serial connection with the modem
    modemSerial.begin(modemBaud);

    // Set up pins for the LED's
    pinMode(greenLED, OUTPUT);
    digitalWrite(greenLED, LOW);
    pinMode(redLED, OUTPUT);
    digitalWrite(redLED, LOW);
    // Blink the LEDs to show the board is on and starting up
    greenredflash();

    // Set the timezones for the logger/data and the RTC
    // Logging in the given time zone
    Logger::setLoggerTimeZone(timeZone);
    // It is STRONGLY RECOMMENDED that you set the RTC to be in UTC (UTC+0)
    Logger::setRTCTimeZone(0);

    // Attach the modem and information pins to the logger
    dataLogger.attachModem(modem);
    modem.setModemLED(modemLEDPin);
    dataLogger.setLoggerPins(wakePin, sdCardSSPin, sdCardPwrPin, buttonPin,
                             greenLED);

    // Begin the variable array[s], logger[s], and publisher[s]
    varArray.begin(variableCount, variableList);
    dataLogger.begin(LoggerID, loggingInterval, &varArray);
    TsMqtt.begin(dataLogger, &modem.gsmClient, thingSpeakMQTTKey,
                 thingSpeakChannelID, thingSpeakChannelKey);

    // Note:  Please change these battery voltages to match your battery
    // Set up the sensors, except at lowest battery level
    if (getBatteryVoltage() > 3.4) {
        Serial.println(F("Setting up sensors..."));
        varArray.setupSensors();
    }

    // Sync the clock if it isn't valid or we have battery to spare
    if (getBatteryVoltage() > 3.55 || !dataLogger.isRTCSane()) {
        // Synchronize the RTC with NIST
        // This will also set up the modem
        dataLogger.syncRTC();
    }

    // Create the log file, adding the default header to it
    // Do this last so we have the best chance of getting the time correct and
    // all sensor names correct
    // Writing to the SD card can be power intensive, so if we're skipping
    // the sensor setup we'll skip this too.
    if (getBatteryVoltage() > 3.4) {
        Serial.println(F("Setting up file on SD card"));
        dataLogger.turnOnSDcard(
            true);  // true = wait for card to settle after power up
        dataLogger.createLogFile(true);  // true = write a new header
        dataLogger.turnOffSDcard(
            true);  // true = wait for internal housekeeping after write
    }

    // Call the processor sleep
    Serial.println(F("Putting processor to sleep"));
    dataLogger.systemSleep();
}
/** End [setup] */


// ==========================================================================
//  Arduino Loop Function
// ==========================================================================
/** Start [loop] */
// Use this short loop for simple data logging and sending
void loop() {
    // Note:  Please change these battery voltages to match your battery
    // At very low battery, just go back to sleep
    if (getBatteryVoltage() < 3.4) {
        dataLogger.systemSleep();
    }
    // At moderate voltage, log data but don't send it over the modem
    else if (getBatteryVoltage() < 3.55) {
        dataLogger.logData();
    }
    // If the battery is good, send the data to the world
    else {
        dataLogger.logDataAndPublish();
    }
}
/** End [loop] */