ModularSensors > Examples > logging_to_MMW.ino

logging_to_MMW.ino example

Monitor My Watershed Example

This sketch reduces menu_a_la_carte.ino to provide an example of how to log to from two sensors, the BME280 and DS18. To complete the set up for logging to the web portal, the UUIDs for the site and each variable would need to be added to the sketch.

The settings for other data portals were removed from the example.

The modem settings were left unchanged because the sketch will test successfully without modem connection (wait patiently, it takes a few minutes).

This is the example you should use to deploy a logger with a modem to stream live data to the Monitor My Watershed data portal.

Unique Features of the Monitor My Watershed Example

  • A single logger publishes data to the Monitor My Watershed data portal.
  • Uses a cellular Digi XBee or XBee3

To Use this Example:

Prepare and set up PlatformIO

  • Register a site and sensors at the Monitor My Watershed/EnviroDIY data portal (
  • Create a new PlatformIO project
  • Replace the contents of the platformio.ini for your new project with the platformio.ini file in the examples/logging_to_MMW folder on GitHub.
    • It is important that your PlatformIO configuration has the lib_ldf_mode and build flags set as they are in the example.
    • Without this, the program won't compile.
  • Open logging_to_MMW.ino and save it to your computer.
    • After opening the link, you should be able to right click anywhere on the page and select "Save Page As".
    • Move it into the src directory of your project.
    • Delete main.cpp in that folder.

Set the logger ID

  • Change the "XXXX" in this section of code to the loggerID assigned by Stroud:
// Logger ID, also becomes the prefix for the name of the data file on SD card
const char *LoggerID = "XXXX";

Set the universally universal identifiers (UUID) for each variable

  • Go back to the web page for your site at the Monitor My Watershed/EnviroDIY data portal (
  • For each variable, find the dummy UUID ("12345678-abcd-1234-ef00-1234567890ab") and replace it with the real UUID for the variable.


  • Test everything at home before deploying out in the wild!

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

description = ModularSensors example menu_a_la_carte with two external sensors logging to Monitor My Watershed

monitor_speed = 115200
board = mayfly
platform = atmelavr
framework = arduino
lib_ldf_mode = deep+
lib_ignore =
    Adafruit NeoPixel
    Adafruit GFX Library
    Adafruit SSD1306
    Adafruit ADXL343
    Adafruit STMPE610
    Adafruit TouchScreen
    Adafruit ILI9341
build_flags =
lib_deps =
;  ^^ Use this when working from an official release of the library
;  ^^ Use this when if you want to pull from the develop branch

The Complete Code

/** =========================================================================
 * @file logging_to_MMW.ino
 * @brief Example logging data and publishing to Monitor My Watershed.
 * @author Sara Geleskie Damiano <>
 * @copyright (c) 2017-2020 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
 * ======================================================================= */

// ==========================================================================
//  Defines for the Arduino IDE
//  NOTE:  These are ONLY needed to compile with the Arduino IDE.
//         If you use PlatformIO, you should set these build flags in your
//         platformio.ini
// ==========================================================================
/** Start [defines] */
/** 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 MMW.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 = 5;
// 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 [xbee_cell_transparent] */
// For any Digi Cellular XBee's
// NOTE:  The u-blox based Digi XBee's (3G global and LTE-M global) can be used
// in either bypass or transparent mode, each with pros and cons
// The Telit based Digi XBees (LTE Cat1) can only use this mode.
#include <modems/DigiXBeeCellularTransparent.h>

// Create a reference to the serial port for the modem
HardwareSerial& modemSerial = Serial1;  // Use hardware serial if possible
const int32_t   modemBaud   = 9600;     // All XBee's use 9600 by default

// 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 modemStatusPin = 19;     // MCU pin used to read modem status
const bool useCTSforStatus  = false;  // Flag to use the XBee CTS pin for status
const int8_t modemResetPin  = 20;     // MCU pin connected to modem reset pin
const int8_t modemSleepRqPin = 23;    // MCU pin for modem sleep/wake request
const int8_t modemLEDPin = redLED;    // MCU pin connected an LED to show modem
                                      // status (-1 if unconnected)

// Network connection information
const char* apn = "xxxxx";  // The APN for the gprs connection

// NOTE:  If possible, use the `STATUS/SLEEP_not` (XBee pin 13) for status, but
// the `CTS` pin can also be used if necessary
DigiXBeeCellularTransparent modemXBCT(&modemSerial, modemVccPin, modemStatusPin,
                                      useCTSforStatus, modemResetPin,
                                      modemSleepRqPin, apn);
// Create an extra reference to the modem by a generic name
DigiXBeeCellularTransparent modem = modemXBCT;
/** End [xbee_cell_transparent] */

// ==========================================================================
//  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 = "v0.5b";
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] */

// ==========================================================================
//  Bosch BME280 Environmental Sensor
// ==========================================================================
/** Start [bme280] */
#include <sensors/BoschBME280.h>

const int8_t I2CPower    = sensorPowerPin;  // Power pin (-1 if unconnected)
uint8_t      BMEi2c_addr = 0x76;
// The BME280 can be addressed either as 0x77 (Adafruit default) or 0x76 (Grove
// default) Either can be physically mofidied for the other address

// Create a Bosch BME280 sensor object
BoschBME280 bme280(I2CPower, BMEi2c_addr);
/** End [bme280] */

// ==========================================================================
//  Maxim DS18 One Wire Temperature Sensor
// ==========================================================================
/** Start [ds18] */
#include <sensors/MaximDS18.h>

// OneWire Address [array of 8 hex characters]
// If only using a single sensor on the OneWire bus, you may omit the address
// DeviceAddress OneWireAddress1 = {0x28, 0xFF, 0xBD, 0xBA, 0x81, 0x16, 0x03,
// 0x0C};
const int8_t OneWirePower = sensorPowerPin;  // Power pin (-1 if unconnected)
const int8_t OneWireBus   = 6;  // OneWire Bus Pin (-1 if unconnected)

// Create a Maxim DS18 sensor objects (use this form for a known address)
// MaximDS18 ds18(OneWireAddress1, OneWirePower, OneWireBus);

// Create a Maxim DS18 sensor object (use this form for a single sensor on bus
// with an unknown address)
MaximDS18 ds18(OneWirePower, OneWireBus);
/** End [ds18] */

// ==========================================================================
//  Creating the Variable Array[s] and Filling with Variable Objects
// ==========================================================================
/** Start [variable_arrays] */
Variable* variableList[] = {
    new ProcessorStats_SampleNumber(&mcuBoard,
    new BoschBME280_Temp(&bme280, "12345678-abcd-1234-ef00-1234567890ab"),
    new BoschBME280_Humidity(&bme280, "12345678-abcd-1234-ef00-1234567890ab"),
    new BoschBME280_Pressure(&bme280, "12345678-abcd-1234-ef00-1234567890ab"),
    new BoschBME280_Altitude(&bme280, "12345678-abcd-1234-ef00-1234567890ab"),
    new MaximDS18_Temp(&ds18, "12345678-abcd-1234-ef00-1234567890ab"),
    new ProcessorStats_Battery(&mcuBoard,
    new MaximDS3231_Temp(&ds3231, "12345678-abcd-1234-ef00-1234567890ab"),
    new Modem_RSSI(&modem, "12345678-abcd-1234-ef00-1234567890ab"),
    new Modem_SignalPercent(&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(variableCount, variableList);
/** End [variable_arrays] */

// ==========================================================================
//  The Logger Object[s]
// ==========================================================================
/** Start [loggers] */
// Create a new logger instance
Logger dataLogger(LoggerID, loggingInterval, &varArray);
/** End [loggers] */

// ==========================================================================
//  Creating Data Publisher[s]
// ==========================================================================
/** Start [publishers] */
// A Publisher to Monitor My Watershed / EnviroDIY Data Sharing Portal
// Device registration and sampling feature information can be obtained after
// registration at or
const char* registrationToken =
    "12345678-abcd-1234-ef00-1234567890ab";  // Device registration token
const char* samplingFeature =
    "12345678-abcd-1234-ef00-1234567890ab";  // Sampling feature UUID

// Create a data publisher for the Monitor My Watershed/EnviroDIY POST endpoint
#include <publishers/EnviroDIYPublisher.h>
EnviroDIYPublisher EnviroDIYPOST(dataLogger, &modem.gsmClient,
                                 registrationToken, samplingFeature);
/** End [publishers] */

// ==========================================================================
//  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);
        digitalWrite(greenLED, LOW);
        digitalWrite(redLED, HIGH);
    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() {
// Wait for USB connection to be established by PC
// NOTE:  Only use this when debugging - if not connected to a PC, this
// could prevent the script from starting
    while (!SERIAL_PORT_USBVIRTUAL && (millis() < 10000)) {}

    // Start the primary serial connection

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

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

// Allow interrupts for software serial
#if defined SoftwareSerial_ExtInts_h
    enableInterrupt(softSerialRx, SoftwareSerial_ExtInts::handle_interrupt,
#if defined NeoSWSerial_h
    enableInterrupt(neoSSerial1Rx, neoSSerial1ISR, CHANGE);

    // Start the serial connection with the modem

    // 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

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

    // Attach the modem and information pins to the logger
    dataLogger.setLoggerPins(wakePin, sdCardSSPin, sdCardPwrPin, buttonPin,

    // Begin the logger

    // 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..."));

    // 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

    // 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"));
            true);  // true = wait for card to settle after power up
        dataLogger.createLogFile(true);  // true = write a new header
            true);  // true = wait for internal housekeeping after write

    // Call the processor sleep
    Serial.println(F("Putting processor to sleep\n"));
/** 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) {
    // At moderate voltage, log data but don't send it over the modem
    else if (getBatteryVoltage() < 3.55) {
    // If the battery is good, send the data to the world
    else {
/** End [loop] */