Hello there,
Currently I am doing a school project about water quality.
I have connected many sensors such as DF Robot's 5v pH sensor, 5v Turbidity sensor and a TDS sensor to a Ardunio Uno. I've also connected a I2C Lcd to the Arduino UNO to display what the sensors are showing. All of that works.
The ESP32 microcontroller is compatible with Arduino IOT cloud dashboard and has WiFi and Bluetooth built in.
My idea is to connect the ESP32 to the Arduino Uno via a Logic Converter (Converts the Uno's 5v to 3.3v) so the UNO can transfer the data outputted by the sensors to the ESP32 so it can upload it to the Arduino Dashboard. Any ideas on the communication between the two?
p.s I cant directly hook up the sensors to the ESP because it consumes 5v and the ESP outputs mainly 3.3v
The Arduino UNO is not compatible with the IOT dashboard.
can be done - what communications are you planning to use? serial, I2C, ???
if serial you can use a potential divider on the UNO Tx to ESP32 Rx pin
e.g. see arduino-mega-2560-serial-communication-to-esp8266
if I2C you require a full level converter
you can transmit serial data as binary or text parsing it and assigning results to variables
e.g. you could transmit comma seperated values
12,456,-78,2.3,567.7,-78.9
have a look at serial-input-basics-updated
give an example of what your data transfer would look like
It might be simpler and more chance of success if you remove the Uno and connect the sensors and LCD directly to the ESP32.
You will need to adapt the 5V LCD and sensors to work with the 3.3V ESP, but that should be simpler than getting 2 Arduino to communicate with each other, which is always much more difficult than beginners realise.
You can use a logic level adaptor between the LCD and the ESP.
Post details of your sensors and we can suggest ways to adapt those to work with the ESP.
When I run a i2c scanner on the UNO it shows that the ESP32 has 32 addresses, however if I choose one address and use the uno to send a msg, on the esp it does not show up.
Modify the project guidelines and omit the UNO. For your 5V Sensors you can use the level shifter you would also need in the case when you connect the ESP32 and UNO.
// Wire Master Writer
// by Nicholas Zambetti <http://www.zambetti.com>
// Demonstrates use of the Wire library
// Writes data to an I2C/TWI Peripheral device
// Refer to the "Wire Peripheral Receiver" example for use with this
// Created 29 March 2006
// This example code is in the public domain.
#include <Wire.h>
void setup()
{
Wire.begin(); // join i2c bus (address optional for master)
}
byte x = 0;
void loop()
{
Wire.beginTransmission(1); // transmit to device #4
Wire.write("hi"); // sends five bytes
Wire.write(x); // sends one byte
Wire.endTransmission(); // stop transmitting
x++;
delay(500);
}
Code for ESP32
// Wire Peripheral Receiver
// by Nicholas Zambetti <http://www.zambetti.com>
// Demonstrates use of the Wire library
// Receives data as an I2C/TWI Peripheral device
// Refer to the "Wire Master Writer" example for use with this
// Created 29 March 2006
// This example code is in the public domain.
#include <Wire.h>
void setup()
{
Wire.begin(1); // join i2c bus with address #4
Wire.onReceive(receiveEvent); // register event
Serial.begin(115200); // start serial for output
}
void loop()
{
delay(100);
}
// function that executes whenever data is received from master
// this function is registered as an event, see setup()
void receiveEvent(int howMany)
{
while(1 < Wire.available()) // loop through all but the last
{
char c = Wire.read(); // receive byte as a character
Serial.print(c); // print the character
}
int x = Wire.read(); // receive byte as an integer
Serial.println(x); // print the integer
}
here are also the I2C ports read by the ESP32 using a scanner:
I have problem to configure ESP32 as I2C-Slave. So, I have configured ESP32 as I2C-Master and UNO as I2C-Slave. The working sketches are given below ; where, ESP32 recognizes UNO as I2-Slave at slaveAddress 0x23. Connect your all 5V sensors with UNO and collect data from UNO by the ESP32 using I2C protocol.
ESP32-I2CMaster Sketch:
#include<Wire.h>
void setup()
{
Serial.begin(9600);
Wire.begin(21, 22); //SDA, SCL
//--------------
}
void loop()
{
Wire.beginTransmission(0x23);
byte busStatus = Wire.endTransmission();
if (busStatus != 0)
{
Serial.print("UNO is not found!");
while (1); //wait for ever
}
Serial.println("UNO is found.");
delay(1000);
}
Well, when in the future it comes your turn to write some project guidelines, I hope you will remember back to this project and take care not to write stupid guidelines! Project guidelines should describe what is to be done, not how it is to be done or which components must or must not be used.
