ESP32 and MQTT Setup/Questions - PH Data

[jaysal]

Hello, I was wondering if someone can help me out publishing data to my MQTT broker running in HA. I have other Tasmota devices communicating with the broker so I know that side is setup correctly. I now have an ESP32 that is running code (Using Arduino IDE) to read data from a DFRobot PH Sensor. I just need help adding the code for the MQTT connecting and publishing the PH Values every 5 seconds or so. Here is what I have so far. I attempted to send "Hello" at the bottom of the code as a test but nothing seems to come over to HA. Any help would be greatly appreciated.

I can see the ph data come across in the serial monitor.

Code: Select all

#include <Arduino.h>
#include "DFRobot_ESP_PH_WITH_ADC.h"
#include "OneWire.h"
#include "DallasTemperature.h"
#include "Adafruit_ADS1015.h"
#include "EEPROM.h"
#include "WiFi.h"
#include <PubSubClient.h>




const char* ssid = "SSID"; //Enter SSID
const char* password = "PASSWORD"; //Enter Password
const char* mqtt_server = "192.168.1.70";
const int mqtt_port = 1883;
const char* mqttUser = "USER";
const char* mqttPassword = "PASS";

WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;
#define MSG_BUFFER_SIZE  (50)
char msg[MSG_BUFFER_SIZE];
int value = 0;


#define ONE_WIRE_BUS 15
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);



DFRobot_ESP_PH_WITH_ADC ph;
Adafruit_ADS1115 ads;

float voltage, phValue, temperature = 25;

float readTemperature()
{
  //add your code here to get the temperature from your temperature sensor
  sensors.requestTemperatures();
  return sensors.getTempCByIndex(0);
}

void setup()
{
  Serial.begin(115200);
  EEPROM.begin(32);//needed EEPROM.begin to store calibration k in eeprom
  ph.begin();
  sensors.begin();
  ads.setGain(GAIN_ONE);
  ads.begin();
  WiFi.begin(ssid, password);
  Serial.println("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println();


}

void loop()
{
  static unsigned long timepoint = millis();
  if (millis() - timepoint > 1000U) //time interval: 1s
  {
    timepoint = millis();
    /**
     * index 0 for adc's pin A0
     * index 1 for adc's pin A1
     * index 2 for adc's pin A2
     * index 3 for adc's pin A3
    */
    voltage = ads.readADC_SingleEnded(1) / 10; // read the voltage
    Serial.print("voltage:");
    Serial.println(voltage, 4);

    temperature = readTemperature(); // read your temperature sensor to execute temperature compensation
    Serial.print("temperature:");
    Serial.print(temperature, 1);
    Serial.println("^C");

    phValue = ph.readPH(voltage, temperature); // convert voltage to pH with temperature compensation
    Serial.print("pH:");
    Serial.println(phValue, 4);
  }
  ph.calibration(voltage, temperature); // calibration process by Serail CMD
  
  client.publish("ESP32", "Hello");
  client.subscribe("ESP32");
  delay(5000);
  
}

[Shimbob]

Looks like you're not setting up mqtt before using it.
There's some stuff that goes into setup(), pick apart my sketch for the mqtt bits.

[jaysal]

Looks like you're not setting up mqtt before using it.
There's some stuff that goes into setup(), pick apart my sketch for the mqtt bits.

Hey Shimbob,yes you are correct. I think I am getting closer now, I can publish a static text to Node-Red every 5 seconds but now when I try to send over a float value I get an error while trying to complie.
Here is the updated code.

Code: Select all

#include <Arduino.h>
#include "DFRobot_ESP_PH_WITH_ADC.h"
#include "OneWire.h"
#include "DallasTemperature.h"
#include "Adafruit_ADS1015.h"
#include "EEPROM.h"
#include "WiFi.h"
#include <PubSubClient.h>

const char* ssid = "SSID";
const char* password = "PASS";
const char* mqttServer = "192.168.1.70";
const int mqttPort = 1883;
const char* mqttUser = "user";
const char* mqttPassword = "pass";

WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;

//GPIO where the DS18B20 is connected to
#define ONE_WIRE_BUS 15
//Setup a onWire instance to communicate with any OneWire devices
OneWire oneWire(ONE_WIRE_BUS);
//Password onewire to Dallas Temperature sensor
DallasTemperature sensors(&oneWire);



DFRobot_ESP_PH_WITH_ADC ph;
Adafruit_ADS1115 ads;

float voltage, phValue, temperature = 25;

float readTemperature()
{
  //add your code here to get the temperature from your temperature sensor
  sensors.requestTemperatures();
  return sensors.getTempCByIndex(0);
}

void setup()
{
  Serial.begin(115200);
  EEPROM.begin(32);//needed EEPROM.begin to store calibration k in eeprom
  ph.begin();
  sensors.begin();
  ads.setGain(GAIN_ONE);
  ads.begin();
  
//Connect to WiFi
WiFi.begin(ssid, password);
Serial.println("Connecting to WiFi");
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.println("Connecting to WiFi..");
}
 
Serial.println("Connected to the WiFi network");
    Serial.println("IP address: ");
    Serial.println(WiFi.localIP());
 
client.setServer(mqttServer, mqttPort);
 
while (!client.connected()) {
Serial.println("Connecting to MQTT...");
 
if (client.connect("ESP32Client", mqttUser, mqttPassword )) {
 
Serial.println("connected");
 
} else {
 
Serial.print("failed with state ");
Serial.print(client.state());
delay(2000);


}

void loop() {
  
  static unsigned long timepoint = millis();
  if (millis() - timepoint > 1000U) //time interval: 1s
  {
    timepoint = millis();
    /**
     * index 0 for adc's pin A0
     * index 1 for adc's pin A1
     * index 2 for adc's pin A2
     * index 3 for adc's pin A3
    */
    voltage = ads.readADC_SingleEnded(1) / 10; // read the voltage
    Serial.print("voltage:");
    Serial.println(voltage, 4);

    temperature = readTemperature(); // read your temperature sensor to execute temperature compensation
    Serial.print("temperature:");
    Serial.print(temperature, 1);
    Serial.println("^C");

    phValue = ph.readPH(voltage, temperature); // convert voltage to pH with temperature compensation
    Serial.print("pH:");
    Serial.println(phValue, 4);
  }
  ph.calibration(voltage, temperature); // calibration process by Serail CMD
//Send data to Node-Red every 5 seconds  
client.publish("esp32/esp32ph", phValue);
delay(5000);
  
}

[Shimbob]

You're missing two closing curly brackets in your setup(), try this:

Code: Select all

void setup()
{
  Serial.begin(115200);
  EEPROM.begin(32);//needed EEPROM.begin to store calibration k in eeprom
  ph.begin();
  sensors.begin();
  ads.setGain(GAIN_ONE);
  ads.begin();
  
  //Connect to WiFi
  WiFi.begin(ssid, password);
  Serial.println("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.println("Connecting to WiFi..");
  }
 
  Serial.println("Connected to the WiFi network");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
 
  client.setServer(mqttServer, mqttPort);
 
  while (!client.connected()) {
    Serial.println("Connecting to MQTT...");
    if (client.connect("ESP32Client", mqttUser, mqttPassword )) {
      Serial.println("connected");
    } else {
      Serial.print("failed with state ");
      Serial.print(client.state());
      delay(2000);
    }
  }
}

I'm assuming you set up your mtqq broker to have a login&password correctly?

[jaysal]

You're missing two closing curly brackets in your setup(), try this:

Code: Select all

void setup()
{
  Serial.begin(115200);
  EEPROM.begin(32);//needed EEPROM.begin to store calibration k in eeprom
  ph.begin();
  sensors.begin();
  ads.setGain(GAIN_ONE);
  ads.begin();
  
  //Connect to WiFi
  WiFi.begin(ssid, password);
  Serial.println("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.println("Connecting to WiFi..");
  }
 
  Serial.println("Connected to the WiFi network");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
 
  client.setServer(mqttServer, mqttPort);
 
  while (!client.connected()) {
    Serial.println("Connecting to MQTT...");
    if (client.connect("ESP32Client", mqttUser, mqttPassword )) {
      Serial.println("connected");
    } else {
      Serial.print("failed with state ");
      Serial.print(client.state());
      delay(2000);
    }
  }
}

I'm assuming you set up your mtqq broker to have a login&password correctly?

Thank you! That did it, I added another curly bracket at the end of setup and it verified straight away. This is my first time working with Arduino IDE code so I have so much to learn. Yes, my MQTT broker has a login and password requirement which I did place in my code.

I am almost there, I just need to publish the phValue every 5 seconds. Here is my next error message, I think I am missing a const char ? or maybe need to convert the value into a string?

[Shimbob]

Instead of

Code: Select all

//Send data to Node-Red every 5 seconds  
client.publish("esp32/esp32ph", phValue);

something like:

Code: Select all

//Send data to Node-Red every 5 seconds  
char tempString[8];
dtostrf(phValue, 5, 3, tempString);
client.publish("esp32/esp32ph", tempString);

[jaysal]

Instead of

Code: Select all

//Send data to Node-Red every 5 seconds  
client.publish("esp32/esp32ph", phValue);

something like:

Code: Select all

//Send data to Node-Red every 5 seconds  
char tempString[8];
dtostrf(phValue, 5, 3, tempString);
client.publish("esp32/esp32ph", tempString);

Wow thank you my friend! Works like a charm. Thank you very much shimbob, I was up for hours yesterday trying to figure this out.

MQTT_PH.PNG (3.42 KiB) Viewed 1904 times

Here is my a pic of the hardware setup. The connections are soldered on the back of the board. I would like to implement an EC probe in the future however DFRobot currently does not offer an industrial version.

[Baylos]

Looks great!

They have a guide on the webpage. If you have a look at it, look at the EC probe It is from ATLAS.

https://www.dfrobot.com/blog-733.html


Greetings

[jaysal]

Looks great!

They have a guide on the webpage. If you have a look at it, look at the EC probe It is from ATLAS.

https://www.dfrobot.com/blog-733.html


Greetings

Thanks! haha, it is from Atlas, I just cant bring myself to pay $250 for a single EC probe. Someone else here mentioned ufire ec and ph probes, I can get an EC interface and probe from them for $100. I wonder if anyone has gone through the setup on one of those.

[Baylos]

My DFRobot EC Probe will come soon. Let's see how long the durability is.

By the way, I found a cheaper solution to make an EC probe

https://hackaday.io/project/7008-fly-wa ... er-arduino