i2cscanner.go

// NUCLEO-L432KC
// GND to GND
// SCL to D5
// SDA to D4
package main

import (
	"fmt"
	"machine"
	"time"
)

func main() {
	machine.I2C0.Configure(machine.I2CConfig{})

	led := machine.LED
	led.Configure(machine.PinConfig{Mode: machine.PinOutput})
	if true {
		for {
			fmt.Printf("\r\n    0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F")
			fmt.Printf("\r\n")
			for y := uint16(0); y < 0x8; y++ {
				led.Low()
				time.Sleep(time.Millisecond * 200)
				fmt.Printf("\r%02x", y*0x10)
				for x := uint16(0); x < 0x10; x++ {
					i2caddr := y*0x10 + x
					err := machine.I2C0.Tx(i2caddr, []byte{0}, nil)
					if err == nil {
						fmt.Printf(" %02x", i2caddr)
					} else {
						fmt.Print(" --")
					}
					led.High()
					time.Sleep(100 * time.Millisecond)
				}
				fmt.Println("")
			}
			fmt.Println("")
		}
	}
}

Modularized i2cscanner:

func i2cScan(bus drivers.I2C) {
	const wait = 10 * time.Millisecond
	fmt.Printf("\r\n    0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F")
	fmt.Printf("\r\n")
	for y := uint16(0); y < 0x8; y++ {
		time.Sleep(2 * wait)
		fmt.Printf("\r%02x", y*0x10)
		for x := uint16(0); x < 0x10; x++ {
			i2caddr := y*0x10 + x
			err := bus.Tx(i2caddr, []byte{0}, nil)
			if err == nil {
				fmt.Printf(" %02x", i2caddr)
			} else {
				fmt.Print(" --")
			}
			time.Sleep(wait)
		}
		fmt.Println("")
	}
	fmt.Println("")
}