IC2 scanner reports no IC2 devices on ESP32-S3 + XIAO Expansion base

What am I doing wrong?

I can’t connect to any IC2 devices?

I’ve ESP32-S3 plugged into an XIAO Grove Shield Expansion Base, with any of:

Attached to the either of the 2 plugs marked (Gnd, 3v3, SDA 4, SCL 5). I’ve tried one or two devices connected to either or both ports.

I’m running code straight from

as shown below

// --------------------------------------
// i2c_scanner
//
// Version 1
//    This program (or code that looks like it)
//    can be found in many places.
//    For example on the Arduino.cc forum.
//    The original author is not know.
// Version 2, Juni 2012, Using Arduino 1.0.1
//     Adapted to be as simple as possible by Arduino.cc user Krodal
// Version 3, Feb 26  2013
//    V3 by louarnold
// Version 4, March 3, 2013, Using Arduino 1.0.3
//    by Arduino.cc user Krodal.
//    Changes by louarnold removed.
//    Scanning addresses changed from 0...127 to 1...119,
//    according to the i2c scanner by Nick Gammon
//    https://www.gammon.com.au/forum/?id=10896
// Version 5, March 28, 2013
//    As version 4, but address scans now to 127.
//    A sensor seems to use address 120.
// Version 6, November 27, 2015.
//    Added waiting for the Leonardo serial communication.
//
//
// This sketch tests the standard 7-bit addresses
// Devices with higher bit address might not be seen properly.
//

#include <Wire.h>

void setup()
{
    Wire.begin();

    Serial.begin(9600);
    while (!Serial)
        ; // Leonardo: wait for serial monitor
    Serial.println("\nI2C Scanner");
}

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

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

    nDevices = 0;
    for (address = 1; address < 127; address++)
    {
        // The i2c_scanner uses the return value of
        // the Write.endTransmisstion to see if
        // a device did acknowledge to the address.
        Wire.beginTransmission(address);
        error = Wire.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); // wait 5 seconds for next scan
}

The code compiles & uploads & runs fine using Arduino IDE with latest libraries & boards, on Win10 Pro. The Serial monitor indicates it runs but finds no devices.

I’ve a bunch of other Seeed controllers & sensors to try if needed. I presume the Grove connecters that came with the sensors are fine to use. I presume the ESP32-S3 handles pull-up voltage on the IC2 pins OK. What else to check:

  • voltage form the ESP32-S3 matches that expected by the sensors
  • I need to remap the pin numbers somehow?
  • I need to use another library, not the standard WIRE one?

Any suggestions appreciated!

Enjoy your solstice…

Neither Grove board appears to have an I2C interface.

1 Like

Huh. I guess I assumed the Grove connector meant it did. I’ll go back to the documentation again…

MUCH APPRECIATED!

I just plugged in a Grove High Precision RTC which is labeled as using IC2 … and it DID show up. Arrrg. Thanks for that very astute observation!