How to get accelerometer value of Thingy:91?

[Yusuke]

I want to tranceive data to ADXL362 through SPI and refer to this program.

https://github.com/Rallare/fw-nrfconnect-nrf/tree/nrf9160_samples/samples/nrf9160/spi

However, I can't get data.

I only modified tx_buffer value.

void spi_test_send(void)
{
	int err;
	u8_t tx_buffer[1] = {0x00}; // Modified here
	u8_t rx_buffer[1];

	const struct spi_buf tx_buf = {
		.buf = tx_buffer,
		.len = sizeof(tx_buffer)
	};
	const struct spi_buf_set tx = {
		.buffers = &tx_buf,
		.count = 1
	};

	struct spi_buf rx_buf = {
		.buf = rx_buffer,
		.len = sizeof(rx_buffer),
	};
	const struct spi_buf_set rx = {
		.buffers = &rx_buf,
		.count = 1
	};

	err = spi_transceive(accel_spi_dev, &spi_cfg, &tx, &rx);
	if (err) {
		printk("SPI error: %d\n", err);
	} else {
		/* Connect MISO to MOSI for loopback */
		printk("TX sent: 0x%02x\n", tx_buffer[0]);
		printk("RX recv: 0x%02x\n", rx_buffer[0]);
//		tx_buffer[0]++;
	}	
}

Also, I added nrf9160_pca20035_v0_3_0.overlay file.

Any tip?

[Didrik Rokhaug]

Hi.

There is a driver for the ADXL362 in Zephyr that implements Zephyr sensor API. The easiest approach is to use that.

The Thingy:91 source code is present in the master branch, where you can see an example of how to use that driver, or you can use the layer the Thingy firmware has built on top of the driver.

Best regards,

Didrik

[MJD093]

I am trying to do the same thing, Zephyr do have a sensor example for the ADXL362.

/path/to/ncs/zephyr/samples/sensor/adxl362

As Didrik says, this example uses the sensor.h API library. Don't ask me how to get it to work though, it straight up refused to get the device for 2 hours then randomly started working and I didn't change the example code apart from enabling SPI in the prj.conf .

[Yusuke]

Thank you guys!

It works!

<prj.conf>

CONFIG_STDOUT_CONSOLE=y
CONFIG_SPI=y
CONFIG_SENSOR=y
CONFIG_ADXL362=y
CONFIG_ADXL362_TRIGGER_GLOBAL_THREAD=y
CONFIG_ADXL362_INTERRUPT_MODE=1
CONFIG_ADXL362_ABS_REF_MODE=1

###########ADD BELOW###########################
# CONFIG_SPI=y
CONFIG_SPI_3=y
CONFIG_SPI_3_NRF_SPIM=y
CONFIG_SPI_3=y 
CONFIG_SPI_NRFX=y
CONFIG_MAIN_STACK_SIZE=4096

[Yusuke]

May I ask one more related question?

I want to configure motion detection function of ADXL362 and let it output H level when it detects movement. This is a simple function.

How can I achieve this? 

To do so, you need to write value in a certain register through SPI. 

However, there is no writing and even reading functions in sensor.h. 

I added the above spi_test_send function to  /path/to/ncs/zephyr/samples/sensor/adxl362 program but it returns -35 error code. Any help?

[MJD093]

To be honest, I would like to know this too. I have no experience with SPI and spi_transceive() didn't seem to fail (returned 0) but I haven't a clue how to read the response.