Wifi kit 32 V3 I2C

#1

How can I make use of the I2C bus in this version?

With V2 I had no problem but this one does not have SDA SCL pins, how can I connect a device through this bus to V3?

I would appreciate it if someone could help me with this. Thanks

#2

Maybe check this post:

Wifi Kit ESP3S3 OLED SCL and SDA?
#3

17/18 on the bottom, they’re little pads. Seems to be the only ones useable on this device.

#4

You should be able to use any two available GPIOs, they just need to be identified/defined through an appropriate Wire1 or TwoWire initialisation (as described in my previous comment above and the various posts in the linked thread). I have used pins 19 (SDA) & 20 (SCL) in my own application.

#5

oled_scl: 18
oled_sda: 17
oled_rst: 21

can be found on the schematic diagram.

I made a little hello world on the pins for the V3.

#6

I have a question more about the I2C bus on a v2 board.
Has anyone managed to use this to connect to the axp192 charge control circuit on these boards.

I have read these boards use the axp192, so should be able to get battery charge status etc from this.
If anyone has an example code of how to access this that would help.
Thanks,
Mark

#7

Sorry to bother you but i could not be able to read any I2C sensor on this Heltec WiFi LoRa V3 board. this is the sketch that i tried:

#include "Arduino.h"
#include "heltec.h"
void setup()
{
  Heltec.begin(true, false, true);
  Wire1.begin(19, 20);  // If there have other device on I2C1, scan the device address via I2C1
}

void loop()
{
  byte error, address;
  int nDevices;

  Serial.println("Scanning...");

  nDevices = 0;
  for (address = 1; address < 127; address++)
  {
    		Wire1.beginTransmission(address);
    		error = Wire1.endTransmission();

    if (error == 0)
    {
      Serial.print("I2C device found at address 0x");
      if (address < 16)
        Serial.print("0");
      Serial.print(address, HEX);
      Serial.println("  !");

      nDevices++;
    }
    else if (error == 4)
    {
      Serial.print("Unknown error at address 0x");
      if (address < 16)
        Serial.print("0");
      Serial.println(address, HEX);
    }
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");

  delay(5000);
}

i have of course a sensor connected to SDA=19 e SCL=20 but no devices is found, do you have some ideas?

#8

Well, first up, get rid of that “heltec.h” help file—I don’t know whether or not there might be something in there getting in the way but, basically, it’s not compatible with the V3 set-up. You’ll then need to add an include for “Wire.h” (or <Wire.h>). See how you go with that.