How to set up nfr9160 feather as an I2C Master with Zephyr

Voxorin

I’m having trouble setting up a basic I2C configuration to write a string to a Adafruit Feather set up as a slave device. I’m using the pins labeled SCL and SCA on the nrf9160 feather.

Could someone provide me with a simple example config, overlay, and I2C write C code?

Thanks!

jaredwolff

Voxorin I’ll be going over the topic at 2P EST on the Live Session: https://youtu.be/qizd2Rk3GNE

Voxorin

Awesome, thank you so much for all the support!

Voxorin

I did finally get a sample working using the nordic nrf-twim driver. For posterity I’ll post it here.

<prj.conf>
# Enable I2C
CONFIG_I2C=y
CONFIG_I2C_NRFX=y

<main.c>
#include <zephyr.h>
#include <stdlib.h>
#include <device.h>
#include <devicetree.h>
#include <drivers/i2c.h>
#include <sys/printk.h>

// 1000 msec = 1 sec
#define SLEEP_TIME_MS 1000

#define MY_I2C "I2C_1"
const struct device *i2c_dev;

void main(void) {
  k_msleep(SLEEP_TIME_MS);
  
  i2c_dev = device_get_binding(MY_I2C);
  if (i2c_dev == NULL) {
    printk("Can't bind I2C device %s\n", MY_I2C);
    return;
  }

  // Write to i2c
  uint8_t i2c_addr = 0x41;
  unsigned char i2c_tx_buffer[] = {'3', '0'};
  i2c_write(i2c_dev, &i2c_tx_buffer, sizeof(i2c_tx_buffer), i2c_addr);
}