Porting from Arduino: Wire.h

Software Development
8

I thought I understood everything based on your comments, Stephen, but I’m having no success. I wonder if you’d have a look at my code?

Here’s the i2cScanner code from Arduino that I’m porting:

#include <Wire.h>
 
void setup()
{
  Wire.begin();
  Serial.begin(9600);
}
 
 
void loop()
{
  Serial.println("Scanning...");
 
  int nDevices = 0;
  for(byte address = 1; address < 127; address++ )
  {
    Wire.beginTransmission(address);
    byte 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++;
    }
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");
 
  delay(5000);           // wait 5 seconds for next scan
}

And the output (connected via A4/A5 to 3 daisy-chained (!) GPIO boards:

Scanning...
I2C device found at address 0x25  !
I2C device found at address 0x26  !
I2C device found at address 0x27  !
done

Here’s my libdaisy version:

#include "daisy_seed.h"

using namespace daisy;

int main(void)
{
    static DaisySeed seed;

    seed.Configure();
    seed.Init();

    seed.StartLog(false);
    System::Delay(5000);

    static constexpr I2CHandle::Config _i2c_config
        = {I2CHandle::Config::Peripheral::I2C_1,
           {{DSY_GPIOB, 8},  // SCL
            {DSY_GPIOB, 9}}, // SDA
           I2CHandle::Config::Speed::I2C_1MHZ};

    I2CHandle _i2c;
    _i2c.Init(_i2c_config);

    seed.PrintLine("Scanning...");

    int      nDevices = 0;
    for(unsigned char address = 1; address < 127; address++)
    {
        uint8_t           testData = 0;
        I2CHandle::Result i2cResult
            = _i2c.TransmitBlocking(address, &testData, 1, 500);

        if(i2cResult == I2CHandle::Result::OK)
        {
            int prAddress = (address < 16) ? 0 : address;
            seed.PrintLine("I2C device found at address %x !", prAddress);
            nDevices++;
        }
    }
    if(nDevices == 0)
        seed.PrintLine("No I2C devices found");
    else
        seed.PrintLine("done");


    while(1) {}
}

And the output when the Seed is connected (pins 12/13 on the pinout):

Daisy is online
===============
Scanning...
No I2C devices found

I’ve tried it at 100KHz, 400KHz, 1MHz with the same result. I can tell that something is happening, because the code completes in 3-4 seconds; with no pin connections, it takes a bit over 60 seconds (as expected to scan 127 addresses with a 1/2 second timeout). I’m probably doing something dumb, but I’m not seeing it. Can you help? Thanks.