Sample program to use asynchronous SPI

[Ubaid_M]

Hi,

I need to know on how to work with asynchronous SPI for my application use case evaluation, However i found no sample/example projects demonstrating the use of nCS API

static inline int spi_transceive_async(const struct device *dev,
				       const struct spi_config *config,
				       const struct spi_buf_set *tx_bufs,
				       const struct spi_buf_set *rx_bufs,
				       struct k_poll_signal *async)

Kindly point me to any example where use of "spi_transceive_async" has been demonstrated.
I am using nRF52833

[dejans]

Hi,

With regard to k_poll_signal, please take a look at the polling-api.

For examples and depending on your use case, you could visit a page with sensor samples - link to sensor samples. There you could find some SPI examples (e.g. BME280 sensor could be connected via SPI).

Best regards,

Dejan

[Ubaid_M]

Hello dejans,

Can you kindly point me to the difference between synchronous SPI & asynchronous SPI..?
As in I need to know where I can use asynchronous SPI & what are it's use cases.

Thanks,

Ubaid

[dejans]

Hi,

You can read more about SPI on our documentation pages - SPI, SPIM and SPIS.
You can also read more about asynchronous notifications and look at test_adc example.

Best regards,
Dejan

[Ubaid_M]

Hello dejans,

My app code using spi_transceive_async always returns error, The API executes successfully, post which it throws a thread error
Can you kindly suggest where it is wrong:

void main(void)
{	struct k_poll_signal async_sig;
	uint8_t data = 40, val =0, sz = 9;

	    struct spi_buf bufs = {
            .buf = &data,
            .len = sizeof(data)
    };
    struct spi_buf_set tx = {
        .buffers = &bufs
    };

    tx.count = 1;

	struct spi_buf rbufs = {
            .buf = &val,
            .len = sizeof(val)
    };
    struct spi_buf_set rx = {
        .buffers = &rbufs
    };

 spi_config spi_cfg;
spi_cs_control cs_ctrl;
    cs_ctrl.gpio_dev = device_get_binding("GPIO_0");
    cs_ctrl.gpio_pin = 11;
    cs_ctrl.delay = 0;
    spi_cfg.operation = SPI_WORD_SET(8) | SPI_OP_MODE_MASTER 
    //                    | SPI_MODE_CPOL | SPI_MODE_CPHA 
                        | SPI_LINES_SINGLE; 
    spi_cfg.frequency = 1000000;
	spi_cfg.cs = &cs_ctrl;

	const device * sp;
	sp = device_get_binding("SPI_0");

		data++;
			struct k_poll_event  async_evt =
		K_POLL_EVENT_INITIALIZER(K_POLL_TYPE_SIGNAL,
					 K_POLL_MODE_NOTIFY_ONLY,
					 &async_sig);

			printk("transmitted data: %u \n", data);
			int error = spi_transceive_async(sp,&spi_cfg,&tx, &rx,&async_sig);
			int ret = k_poll(&async_evt, 1, K_MSEC(1000));
			printk("received data: %u \n", val);

}

Error:

[dejans]

Hi,

You have received an answer in this case.
Since there is no benefit for our customers if we duplicate cases, please continue communication there.

Best regards,
Dejan