hello, i need help with Blynk app here, I connect my two sensors which is temperature and ph sensor to esp32 dev board. the problem is my blynk app keeps telling me the value is 1 until 999 and so on for both sensor. but when i click on serial monitor at arduino ide the reading is ok. what is the problem? is it because of coding?
here the coding:
#define BLYNK_PRINT Serial
#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>
// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "MXTXejFHbSqqRltFZA4kPbV1FT-Tk5Cp";
// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "Huawei Nova 5T";
char pass[] = "breakdance12345";
#include "DFRobot_ESP_PH.h"
#include "EEPROM.h"
#include <OneWire.h>
#include <DallasTemperature.h>
#define ONE_WIRE_BUS 4
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
DeviceAddress insideThermometer;
DFRobot_ESP_PH ph;
#define ESPADC 4096.0 //the esp Analog Digital Convertion value
#define ESPVOLTAGE 3300 //the esp voltage supply value
#define PH_PIN 35 //the esp gpio data pin number
float voltage, phValue, temperature = 25;
BlynkTimer timer;
// This function sends Arduino's up time every second to Virtual Pin (5).
// In the app, Widget's reading frequency should be set to PUSH. This means
// that you define how often to send data to Blynk App.
void myTimerEvent()
{
//add your code here to get the temperature from your temperature sensor
// call sensors.requestTemperatures() to issue a global temperature
// request to all devices on the bus
Serial.print("Requesting temperatures...");
sensors.requestTemperatures(); // Send the command to get temperatures
Serial.println("DONE");
// After we got the temperatures, we can print them here.
// We use the function ByIndex, and as an example get the temperature from the first sensor only.
Serial.print("Temperature is: ");
Serial.println(sensors.getTempCByIndex(0));
Blynk.virtualWrite(V5, millis() / 1000);
}
void myTimerEvent2()
{
static unsigned long timepoint = millis();
if (millis() - timepoint > 1000U) //time interval: 1s
{
timepoint = millis();
//voltage = rawPinValue / esp32ADC * esp32Vin
voltage = analogRead(PH_PIN) / ESPADC * ESPVOLTAGE; // read the voltage
//temperature = readTemperature(); // read your temperature sensor to execute temperature compensation
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
Blynk.virtualWrite(V6, millis() / 1000);
}
void setup()
{
// Debug console
Serial.begin(115200);
EEPROM.begin(32);//needed to permit storage of calibration value in eeprom
ph.begin();
sensors.begin();
Blynk.begin(auth, ssid, pass);
// You can also specify server:
//Blynk.begin(auth, ssid, pass, "blynk-cloud.com", 80);
//Blynk.begin(auth, ssid, pass, IPAddress(192,168,1,100), 8080);
// Setup a function to be called every second
timer.setInterval(1000L, myTimerEvent);
timer.setInterval(1000L, myTimerEvent2);
}
void loop()
{
Blynk.run();
timer.run(); // Initiates BlynkTimer
}
The only data that you are sending to Blynk is the number of milliseconds that have elapsed since the device booted, divided by 1000.
Where you do a serial print of phValue you should follow this with a Blynk.virtualWrite of phValue to your chosen virtual pin.
You’re handling the temperature side of things slightly differently, and would be better to do the same thing that you do with PH. This means storing the reading in the temperature variable that you’ve already declared, then use this when you do your serial print and Blynk.virtualWrite.
Thanks you so much. i appreciate it. now my pH is working in the app.
now i change my temp coding and it didnt work. it keep getting -127. any solution?
{
// Send the command to get temperatures
sensors.requestTemperatures();
//print the temperature in Celsius
Serial.print("Temperature: ");
Serial.print(sensors.getTempCByIndex(0));
Serial.print((char)176);//shows degrees character
Serial.print("C | ");
//print the temperature in Fahrenheit
Serial.print((sensors.getTempCByIndex(0) * 9.0) / 5.0 + 32.0);
Serial.print((char)176);//shows degrees character
Serial.println("F");
Blynk.virtualWrite(V5, sensors.getTempCByIndex(0));
}
Okay, this was your original code for taking temperature readings, after removing the comments:
void myTimerEvent()
{
Serial.print("Requesting temperatures...");
sensors.requestTemperatures(); // Send the command to get temperatures
Serial.println("DONE");
Serial.print("Temperature is: ");
Serial.println(sensors.getTempCByIndex(0));
Blynk.virtualWrite(V5, millis() / 1000);
}
The bit of code inside the serial print statement that says sensors.getTempCByIndex(0) is where the temperature value is obtained.
Rather than outputting it directly to the serial monitor as your original code does, we want to store it in the variable called temperature that you declared earlier…
float voltage, phValue, temperature = 25;
void myTimerEvent()
{
Serial.print("Requesting temperatures...");
sensors.requestTemperatures(); // Send the command to get temperatures
Serial.println("DONE");
temperature = sensors.getTempCByIndex(0); // Save the reading to use later
Serial.print("Temperature is: ");
Serial.println(temperature); // print the reading that we just took
Blynk.virtualWrite(V5, temperature); // and send the same reading to virtual pin 5
}
Does this make sense?
By the way, you are assigning a value of 25 to your temperature variable when you initialise it. If you don’t specify a value - as is the case with the voltage (not sure what you’re using this for) and phValue variables - then they will initialise with a value of zero.
I think a value of zero is more useful in this situation, because you aren’t likely to mistake it for an actual reading (unless the probe is in a freezer), should the process of reading the temperature probe fail to work correctly.
it’s your code. here temp code that i am using latest
{
Serial.print("Requesting temperatures...");
sensors.requestTemperatures(); // Send the command to get temperatures
Serial.println("DONE");
temperature = sensors.getTempCByIndex(0); // Save the reading to use later
Serial.print("Temperature is: ");
Serial.println(temperature); // print the reading that we just took
Blynk.virtualWrite(V5, temperature); // and send the same reading to virtual pin 5
}
do you mean my board? if you mean by board, then i am connecting to esp32 dev board. and i attached my 4.7k ohm resistor because dallas temperature need it. i guess.
-127 is the generic “device not working” message provided by the sensor library. Basically, if there is a physical or electrical issue with your sensor or hookup, any code will provide the same “error” message of -127 for that sensor type.
actually after i tried coding with this code, then i get error -127. but if i revert back to basic code which is no blynk code it work perfectly.
{
// Send the command to get temperatures
sensors.requestTemperatures();
//print the temperature in Celsius
Serial.print("Temperature: ");
Serial.print(sensors.getTempCByIndex(0));
Serial.print((char)176);//shows degrees character
Serial.print("C | ");
//print the temperature in Fahrenheit
Serial.print((sensors.getTempCByIndex(0) * 9.0) / 5.0 + 32.0);
Serial.print((char)176);//shows degrees character
Serial.println("F");
Blynk.virtualWrite(V5, sensors.getTempCByIndex(0));
}
#define BLYNK_PRINT Serial
#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>
// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "MXTXejFHbSqqRltFZA4kPbV1FT-Tk5Cp";
// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "Huawei Nova 5T";
char pass[] = "breakdance12345";
#include "DFRobot_ESP_PH.h"
#include "EEPROM.h"
#include <OneWire.h>
#include <DallasTemperature.h>
#define ONE_WIRE_BUS 4
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
DeviceAddress insideThermometer;
DFRobot_ESP_PH ph;
#define ESPADC 4096.0 //the esp Analog Digital Convertion value
#define ESPVOLTAGE 3300 //the esp voltage supply value
#define PH_PIN 35 //the esp gpio data pin number
float voltage, phValue, temperature = 25;
BlynkTimer timer;
// This function sends Arduino's up time every second to Virtual Pin (5).
// In the app, Widget's reading frequency should be set to PUSH. This means
// that you define how often to send data to Blynk App.
void myTimerEvent()
{
Serial.print("Requesting temperatures...");
sensors.requestTemperatures(); // Send the command to get temperatures
Serial.println("DONE");
temperature = sensors.getTempCByIndex(0); // Save the reading to use later
Serial.print("Temperature is: ");
Serial.println(temperature); // print the reading that we just took
Blynk.virtualWrite(V5, temperature); // and send the same reading to virtual pin 5
}
void myTimerEvent2()
{
static unsigned long timepoint = millis();
if (millis() - timepoint > 1000U) //time interval: 1s
{
timepoint = millis();
//voltage = rawPinValue / esp32ADC * esp32Vin
voltage = analogRead(PH_PIN) / ESPADC * ESPVOLTAGE; // read the voltage
phValue = ph.readPH(voltage, temperature); // convert voltage to pH with temperature compensation
Serial.print("pH:");
Serial.println(phValue, 4);
Blynk.virtualWrite(V6, phValue);
}
ph.calibration(voltage, temperature); // calibration process by Serail CMD
}
void setup()
{
// Debug console
Serial.begin(115200);
EEPROM.begin(32);//needed to permit storage of calibration value in eeprom
ph.begin();
sensors.begin();
Blynk.begin(auth, ssid, pass);
// You can also specify server:
//Blynk.begin(auth, ssid, pass, "blynk-cloud.com", 80);
//Blynk.begin(auth, ssid, pass, IPAddress(192,168,1,100), 8080);
// Setup a function to be called every second
timer.setInterval(1000L, myTimerEvent);
timer.setInterval(1000L, myTimerEvent2);
}
void loop()
{
Blynk.run();
timer.run(); // Initiates BlynkTimer
}
Okay, so previously you said that the correct temperature and humidity readings were shown in the serial monitor.
With this revised code, does the serial monitor show -127, or does it show the correct value?
If you revert to your original code then does it show the correct temperature reading in the serial monitor?
Have you double-checked the connections to your temperature probe?
i tried rerun with this code and it actually working. the temp and ph sensor now is reading in serial and blynk app.
#define BLYNK_PRINT Serial
#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>
// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "MXTXejFHbSqqRltFZA4kPbV1FT-Tk5Cp";
// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "Huawei Nova 5T";
char pass[] = "breakdance12345";
#include "DFRobot_ESP_PH.h"
#include "EEPROM.h"
#include <OneWire.h>
#include <DallasTemperature.h>
#define ONE_WIRE_BUS 4
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
DeviceAddress insideThermometer;
DFRobot_ESP_PH ph;
#define ESPADC 4096.0 //the esp Analog Digital Convertion value
#define ESPVOLTAGE 3300 //the esp voltage supply value
#define PH_PIN 35 //the esp gpio data pin number
float voltage, phValue, temperature = 25;
BlynkTimer timer;
// This function sends Arduino's up time every second to Virtual Pin (5).
// In the app, Widget's reading frequency should be set to PUSH. This means
// that you define how often to send data to Blynk App.
void myTimerEvent()
{
Serial.print("Requesting temperatures...");
sensors.requestTemperatures(); // Send the command to get temperatures
Serial.println("DONE");
temperature = sensors.getTempCByIndex(0); // Save the reading to use later
Serial.print("Temperature is: ");
Serial.println(temperature); // print the reading that we just took
Blynk.virtualWrite(V5, temperature); // and send the same reading to virtual pin 5
}
void myTimerEvent2()
{
static unsigned long timepoint = millis();
if (millis() - timepoint > 1000U) //time interval: 1s
{
timepoint = millis();
//voltage = rawPinValue / esp32ADC * esp32Vin
voltage = analogRead(PH_PIN) / ESPADC * ESPVOLTAGE; // read the voltage
phValue = ph.readPH(voltage, temperature); // convert voltage to pH with temperature compensation
Serial.print("pH:");
Serial.println(phValue, 4);
Blynk.virtualWrite(V6, phValue);
}
ph.calibration(voltage, temperature); // calibration process by Serail CMD
}
void setup()
{
// Debug console
Serial.begin(115200);
EEPROM.begin(32);//needed to permit storage of calibration value in eeprom
ph.begin();
sensors.begin();
Blynk.begin(auth, ssid, pass);
// You can also specify server:
//Blynk.begin(auth, ssid, pass, "blynk-cloud.com", 80);
//Blynk.begin(auth, ssid, pass, IPAddress(192,168,1,100), 8080);
// Setup a function to be called every second
timer.setInterval(1000L, myTimerEvent);
timer.setInterval(1000L, myTimerEvent2);
}
void loop()
{
Blynk.run();
timer.run(); // Initiates BlynkTimer
}
now my new problem is ph sensor keep giving me negative value.
