what means errno -16 for nrf52832?

[hans_mueller]

Hello,

I am using an I2C sensor with my nrf52832 board and if I do the sensor_sample_fetch(dev), I get an error code of -16.

What does that mean?

Is there a table to look up the error codes?

My code looks as follows:

void main(void)
{
	const char *const devname = DT_LABEL(DT_INST(0, microchip_mcp9808));
	const struct device *dev = device_get_binding(devname);
	int rc;

	if (dev == NULL) {
		printf("Device %s not found.\n", devname);
		return;
	}
	
	while (1) {
		struct sensor_value temp;

		rc = sensor_sample_fetch(dev);
		if (rc != 0) {
			printf("sensor_sample_fetch error: %d\n", rc);
			break;
		}

		rc = sensor_channel_get(dev, SENSOR_CHAN_AMBIENT_TEMP, &temp);
		if (rc != 0) {
			printf("sensor_channel_get error: %d\n", rc);
			break;
		}

		printf("%s: %g C\n", now_str(),
		       sensor_value_to_double(&temp));

		k_sleep(K_SECONDS(2));
	}
}

Thank you for your help!

[Simon]

I'll just expand on the answer given by Luis Ubieda. At the highest abstraction layer, the error -16 is EBUSY. However, sometimes, it's useful to dig a little deeper to get a better understanding of the error.

I think the error comes from here  If you do some debugging inside nrfx_twim_xfer(), you'll get a better understanding of it.

---

I'll just provide you the whole call stack below, which may give you a better understanding of the different abstraction layers, how to debug and find errors on a deeper layer

sensor_sample_fetch()-->

api->sample_fetch()-->

.sample_fetch = mcp9808_sample_fetch-->

mcp9808_sample_fetch()-->

mcp9808_reg_read()-->

i2c_write_read()-->

i2c_transfer()-->

.transfer = i2c_nrfx_twim_transfer-->

i2c_nrfx_twim_transfer()-->

nrfx_twim_xfer()

---

Best regards,

Simon