RE: Writing Register problem on Thingy91

Bergmann — Mon, 30 Dec 2019 15:26:56 GMT

I solved it by my own with the help of the timing diagram:

I have a working code for the read area of the diagram and I need a code that works for the write area of the diagram. I need to expand the buffer and send 3 bytes instead of 2. The working code is:

void spi_write_reg(void)
{
  u8_t cmd =      0x0A;
  u8_t reg_addr = 0x20; // register, that you want to write
  u8_t value = 0x46; // value, that you want to set
  void *data = &value;
  int length = 1;
	u8_t access[3] = { cmd, reg_addr, value };

  gpio_pin_write(cs_gpio, cd_pin, 0);

	const struct spi_buf buf[2] = {
		{
			.buf = access,
			.len = 3
		},
		{
			.buf = data,
			.len = length
		}
	};
	struct spi_buf_set tx = {
		.buffers = buf,
	};


	const struct spi_buf_set rx = {
		.buffers = buf,
		.count = 2
	};

	tx.count = 1;

	int spi_result = spi_transceive(spi_dev, &spi_cfg, &tx, &rx);

 // printk("SPI result: %d\n",spi_result);
  printk("Value: 0x%02X\n", value);

  gpio_pin_write(cs_gpio, cd_pin, 1);

}