DRWI Sites with a Mayfly 1.x and EnviroDIY ESP32 WiFi Bee

Example sketch for using the EnviroDIY ESP32 WiFi cellular module with an EnviroDIY Mayfly Data Logger.

The exact hardware configuration used in this example:

Mayfly v1.1 board
EnviroDIY ESP32 WiFi module
Hydros21 CTD sensor

An EnviroDIY ESP32 WiFi module can also be used with the older Mayfly v0.5b boards if you change line 95 (for modemVccPin) from 18 to -1. This is because the Mayfly v1.x board has a separate 3.3v regulator to power the Bee socket and is controlled by turning pin 18 on or off. Mayfly v0.5b has the Bee socket constantly powered, therefore using "-1" is the proper setting for that line of code. Leave the modemVccPin as 18 for Mayfly version 1.0 and 1.1.

The WiFi antenna is built into the ESP32 Bee - no external antenna is needed

Be sure to edit lines 101 and 102 to enter your Wifi access point name and password, and edit the UUID section beginning at line 200 with the correct UUIDs from your specific site on MonitorMyWatershed.

Unique Features of the DRWI Mayfly 1.x WiFi Example

Specifically for sites within the Delaware River Watershed Initiative.
Uses a EnviroDIY WiFi Bee based on the Espressif ESP32-WROOM-32

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 intended for DRWI users with CTD and a EnviroDIY ESP32 Bee

[env:mayfly]
monitor_speed = 57600
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
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

/** =========================================================================
 * @example{lineno} DRWI_Mayfly1_WiFi.ino
 * @copyright Stroud Water Research Center
 * @license This example is published under the BSD-3 license.
 * @author Sara Geleskie Damiano <sdamiano@stroudcenter.org>
 *
 * @brief Example for DRWI CitSci LTE sites.
 *
 * This example shows proper settings for the following configuration:
 *
 * Mayfly v1.x board
 * EnviroDIY ESP32 Wifi Bee module
 * Hydros21 CTD sensor
 *
 * @m_examplenavigation{example_drwi_mayfly1_wifi,}
 * ======================================================================= */

// ==========================================================================
//  Defines for TinyGSM
// ==========================================================================
/** Start [defines] */
#ifndef TINY_GSM_RX_BUFFER
#define TINY_GSM_RX_BUFFER 256
#endif
#ifndef TINY_GSM_YIELD_MS
#define TINY_GSM_YIELD_MS 2
#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>

// 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 = "DRWI_Mayfly1_WiFi.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 = 57600;  // 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, 1.x D31 = A7
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_esp32] */
#include <modems/EspressifESP32.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 the Mayfly.  We'll slow it down in the
// setup.

// Modem Pins - Describe the physical pin connection of your modem to your board
// NOTE:  Use -1 for pins that do not apply
// Example pins here are for a EnviroDIY ESP32 Bluetooth/Wifi Bee with
// Mayfly 1.1
const int8_t modemVccPin   = 18;      // MCU pin controlling modem power
const int8_t modemResetPin = -1;      // 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";  // WiFi access point name
const char* wifiPwd = "xxxxx";  // WiFi password (WPA2)

// Create the modem object
EspressifESP32 modemESP(&modemSerial, modemVccPin, modemResetPin, wifiId,
                        wifiPwd);
// Create an extra reference to the modem by a generic name
EspressifESP32 modem = modemESP;
/** End [espressif_esp32] */


// ==========================================================================
//  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)
//  Built in on all versions of the Mayfly
// ==========================================================================
/** Start [ds3231] */
#include <sensors/MaximDS3231.h>

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


// ==========================================================================
//  Sensirion SHT4X Digital Humidity and Temperature Sensor
//  Built in on Mayfly 1.x
// ==========================================================================
/** Start [sensirion_sht4x] */
#include <sensors/SensirionSHT4x.h>

// NOTE: Use -1 for any pins that don't apply or aren't being used.
const int8_t SHT4xPower     = sensorPowerPin;  // Power pin
const bool   SHT4xUseHeater = true;

// Create an Sensirion SHT4X sensor object
SensirionSHT4x sht4x(SHT4xPower, SHT4xUseHeater);
/** End [sensirion_sht4x] */


// ==========================================================================
//  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 hydros(*hydrosSDI12address, SDI12Power, SDI12Data,
                     hydrosNumberReadings);
/** End [hydros21] */


/* clang-format off */
// ==========================================================================
//  Creating the Variable Array[s] and Filling with Variable Objects
// ==========================================================================
/** Start [variable_arrays] */
Variable* variableList[] = {
    new MeterHydros21_Cond(&hydros),             // Specific conductance (Meter_Hydros21_Cond)
    new MeterHydros21_Depth(&hydros),            // Water depth (Meter_Hydros21_Depth)
    new MeterHydros21_Temp(&hydros),             // Temperature (Meter_Hydros21_Temp)
    new SensirionSHT4x_Humidity(&sht4x),         // Relative humidity (Sensirion_SHT40_Humidity)
    new SensirionSHT4x_Temp(&sht4x),             // Temperature (Sensirion_SHT40_Temperature)
    new ProcessorStats_Battery(&mcuBoard),       // Battery voltage (EnviroDIY_Mayfly_Batt)
    new Modem_SignalPercent(&modem),             // Percent full scale (EnviroDIY_LTEB_SignalPercent)
};

// All UUID's, device registration, and sampling feature information can be
// pasted directly from Monitor My Watershed.
// To get the list, click the "View  token UUID list" button on the upper right
// of the site page.

// *** CAUTION --- CAUTION --- CAUTION --- CAUTION --- CAUTION ***
// Check the order of your variables in the variable list!!!
// Be VERY certain that they match the order of your UUID's!
// Rearrange the variables in the variable list ABOVE if necessary to match!
// Do not change the order of the variables in the section below.
// *** CAUTION --- CAUTION --- CAUTION --- CAUTION --- CAUTION ***

// Replace all of the text in the following section with the UUID array from
// MonitorMyWatershed
// ---------------------   Beginning of Token UUID List   ---------------------


const char* UUIDs[] =  // UUID array for device sensors
    {
        "12345678-abcd-1234-ef00-1234567890ab",  // Specific conductance (Meter_Hydros21_Cond)
        "12345678-abcd-1234-ef00-1234567890ab",  // Water depth (Meter_Hydros21_Depth)
        "12345678-abcd-1234-ef00-1234567890ab",  // Temperature (Meter_Hydros21_Temp)
        "12345678-abcd-1234-ef00-1234567890ab",  // Relative humidity (Sensirion_SHT40_Humidity)
        "12345678-abcd-1234-ef00-1234567890ab",  // Temperature (Sensirion_SHT40_Temperature)
        "12345678-abcd-1234-ef00-1234567890ab",  // Battery voltage (EnviroDIY_Mayfly_Batt)
        "12345678-abcd-1234-ef00-1234567890ab",  // Percent full scale (EnviroDIY_LTEB_SignalPercent)
};
const char* registrationToken = "12345678-abcd-1234-ef00-1234567890ab";  // Device registration token
const char* samplingFeature = "12345678-abcd-1234-ef00-1234567890ab";  // Sampling feature UUID


// -----------------------   End of Token UUID List  -----------------------
/* clang-format on */

// Count up the number of pointers in the array
int variableCount = sizeof(variableList) / sizeof(variableList[0]);

// Create the VariableArray object
VariableArray varArray(variableCount, variableList, UUIDs);
/** 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] */
// 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);
        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];
}


// ==========================================================================
// 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();

    pinMode(20, OUTPUT);  // for proper operation of the onboard flash memory
                          // chip's ChipSelect (Mayfly v1.0 and later)

    // 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 logger
    dataLogger.begin();
    EnviroDIYPOST.begin(dataLogger, &modem.gsmClient, registrationToken,
                        samplingFeature);

    // 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();
    }

    /** Start [setup_esp] */
    for (int8_t ntries = 5; ntries; ntries--) {
        // This will also verify communication and set up the modem
        if (modem.modemWake()) break;
        // if that didn't work, try changing baud rate
        modemSerial.begin(115200);
        modem.gsmModem.sendAT(GF("+UART_DEF=9600,8,1,0,0"));
        modem.gsmModem.waitResponse();
        modemSerial.end();
        modemSerial.begin(9600);
    }
    /** End [setup_esp] */


    // 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\n"));
    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] */

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