RE: SPI slave on NCS v2.0.0

Stian Røed Hafskjold — Thu, 11 Aug 2022 13:47:00 GMT

Ok, thanks for reporting back. You're welcome!

RE: SPI slave on NCS v2.0.0

Anders Esbensen — Wed, 10 Aug 2022 09:21:08 GMT

Update: I got it working using NCS v2.0.0 using the nrfx_spi api directly.

Thank you for your support

RE: SPI slave on NCS v2.0.0

Anders Esbensen — Tue, 09 Aug 2022 13:12:58 GMT

Hi Stian

Thank you for the answer. I have been on vacation so haven't been able to verify until now.

The prj.conf and dts declaration above helped me build my project using NCS v2.0.0.

However I would prefer to use the nrfx_spi api directly due to the design of the SPI protocol in use.

Can you confirm this is still feasible ?

RE: SPI slave on NCS v2.0.0

Stian Røed Hafskjold — Fri, 15 Jul 2022 10:17:00 GMT

Hi,

Yes, this has changed a bit in NCS 2.0.0. Here is an example that works on the nRF52840 DK:

main.c

#include <zephyr.h>
#include <drivers/gpio.h>
#include <drivers/spi.h>
#include <device.h>

const struct device * spi_dev;
static struct spi_config spi_cfg = {
	.operation = SPI_WORD_SET(8)
	         | SPI_OP_MODE_SLAVE
             | SPI_TRANSFER_MSB
             //| SPI_MODE_CPOL
             //| SPI_MODE_CPHA
             ,
	.frequency = 4000000,
	.slave = 1,
};

static struct spi_buf rx;
const struct spi_buf_set rx_bufs = {
	.buffers = &rx,
	.count = 1
};

static struct spi_buf tx;
const struct spi_buf_set tx_bufs = {
	.buffers = &tx,
	.count = 1
};

static void spi_init(void)
{
	spi_dev = device_get_binding(DT_LABEL(DT_NODELABEL(spi2)));
}
void spi_test_send(void)
{
	int err;
	static uint8_t tx_buffer[2] = {0x2A, 0xF0};
	tx.buf = tx_buffer;
	tx.len = sizeof(tx_buffer);

	static uint8_t rx_buffer[2];
	rx.buf = rx_buffer;
	rx.len = sizeof(rx_buffer);

	err = spi_transceive(spi_dev, &spi_cfg, &tx_bufs, &rx_bufs);
	if (err < 0) {
		printk("SPI error: %d\n", err);
	} else {
		printk("RX recv:");
		for (int i = 0; i < err; i++){
			printk(" %x", rx_buffer[i]);
		}
		printk("\n");
	}
}
void main(void)
{
    spi_init();

	while (1) {
		k_msleep(1000);
        spi_test_send();
	}
}

prj.conf

CONFIG_GPIO=y
CONFIG_SPI=y
CONFIG_SPI_NRFX=y
CONFIG_SPI_SLAVE=y

nrf52840dk_nrf52840.overlay

&spi2 {
    compatible = "nordic,nrf-spis";
    status = "okay";
    pinctrl-0 = <&spi2_default_new>;
    pinctrl-1 = <&spi2_sleep_new>;
    def-char = <0xAA>;
};

&pinctrl {
    spi2_default_new: spi2_defalt_new {
        group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 3)>,
                    <NRF_PSEL(SPIM_MISO, 0, 4)>,
                    <NRF_PSEL(SPIM_MOSI, 0, 28)>,
                    <NRF_PSEL(SPIS_CSN, 0, 29)>;
        };
    };
    spi2_sleep_new: spi2_sleep_new {
        group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 3)>,
                    <NRF_PSEL(SPIM_MISO, 0, 4)>,
                    <NRF_PSEL(SPIM_MOSI, 0, 28)>,
                    <NRF_PSEL(SPIS_CSN, 0, 29)>;
        };
    };
};

This code is inspired by the zephyr/sample/bluetooth/hci_spi project. So you can have a look at that project for more details.

Complete project: devzone.nordicsemi.com/.../4532.spis.zip