super epic SPI

CMakeLists.txt

@@ -1,5 +1,9 @@
 cmake_minimum_required(VERSION 3.20.0)
 
+if (EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/${BOARD}.overlay")
+  set(mcuboot_DTC_OVERLAY_FILE "${CMAKE_CURRENT_SOURCE_DIR}/${BOARD}.overlay")
+endif()
+
 find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 project(passr)

Makefile

@@ -1,12 +1,12 @@
 .ONESHELL:
 
-TARGET=rpi_pico
+TARGET=nrf52840dk_nrf52840
 
 CMAKE_ZEPHYR_PATH=../zephyrproject/zephyr
 CMAKE_ZEPHYR_COMMAND=west build
 CMAKE_ZEPHYR_FLAGS=-b $(TARGET)
 
-all: compile flash_pico
+all: compile flash
 
 setup:
 	west init
@@ -14,18 +14,15 @@ setup:
 
 compile:
 	$(CMAKE_ZEPHYR_COMMAND) $(CMAKE_ZEPHYR_FLAGS)
-	cp build/zephyr/zephyr.uf2 ./zephyr.uf2
-	echo "Copied zephyr.uf2 to project root"
 
-flash_pico:
-	# mount then copy the uf2
-	sudo mount -L RPI-RP2 /mnt
-	sudo cp zephyr.uf2 /mnt
-	echo "Copied zephyr.uf2 to pico"
+flash: compile
+	cp build/zephyr/zephyr.hex ./zephyr.hex
+	echo "Copied zephyr.hex to project root"
+	nrfjprog -f nrf52 --program zephyr.hex --sectorerase --verify --log --reset
+	minicom -D /dev/ttyACM0 -b 115200
 
-# FIXME: This is entirely board specific, for example the pi pico will vibe differently
-flash:
-	west flash
+listen:
+	minicom -D /dev/ttyACM0 -b 115200
 
 clean:
 	rm -rf build/

boards/nrf52840dk_nrf52840.overlay

@@ -0,0 +1,63 @@
+&pinctrl {
+	spi_master_default: spi_master_default {
+		group1 {
+			psels = <NRF_PSEL(SPIM_SCK, 0, 31)>,
+					<NRF_PSEL(SPIM_MOSI, 0, 30)>,
+					<NRF_PSEL(SPIM_MISO, 0, 29)>;
+		};
+	};
+
+	spi_master_sleep: spi_master_sleep {
+		group1 {
+			psels = <NRF_PSEL(SPIM_SCK, 0, 31)>,
+					<NRF_PSEL(SPIM_MOSI, 0, 30)>,
+					<NRF_PSEL(SPIM_MISO, 0, 29)>;
+			low-power-enable;
+		};
+	};
+
+	spi_slave_default: spi_slave_default {
+		group1 {
+			psels = <NRF_PSEL(SPIS_SCK, 1, 1)>,
+					<NRF_PSEL(SPIS_MOSI, 1, 2)>,
+					<NRF_PSEL(SPIS_MISO, 1, 3)>,
+					<NRF_PSEL(SPIS_CSN, 1, 4)>;
+		};
+	};
+
+	spi_slave_sleep: spi_slave_sleep {
+		group1 {
+			psels = <NRF_PSEL(SPIS_SCK, 1, 1)>,
+					<NRF_PSEL(SPIS_MOSI, 1, 2)>,
+					<NRF_PSEL(SPIS_MISO, 1, 3)>,
+					<NRF_PSEL(SPIS_CSN, 1, 4)>;
+			low-power-enable;
+		};
+	};
+};
+
+my_spi_master: &spi3 {
+	compatible = "nordic,nrf-spim";
+	status = "okay";
+	pinctrl-0 = <&spi_master_default>;
+	pinctrl-1 = <&spi_master_sleep>;
+	pinctrl-names = "default", "sleep";
+	cs-gpios = <&gpio0 28 GPIO_ACTIVE_LOW>;
+	reg_my_spi_master: spi-dev-a@0 {
+		reg = <0>;
+	};
+};
+
+my_spi_slave: &spi1 {
+	compatible = "nordic,nrf-spis";
+	status = "okay";
+	pinctrl-0 = <&spi_slave_default>;
+	pinctrl-1 = <&spi_slave_sleep>;
+	pinctrl-names = "default", "sleep";
+	def-char = <0x00>;
+};
+
+// By default uart1 will occupy P1.01 and P1.02. In order to make these pins available, disable uart1
+&uart1 {
+	status="disabled";
+};

prj.conf

@@ -1,4 +1,6 @@
-CONFIG_BUILD_OUTPUT_UF2=y
 CONFIG_GPIO=y
+
+CONFIG_SPI=y
 CONFIG_SPI_ASYNC=y
-CONFIG_SPI_PL022_INTERRUPT=y
+
+CONFIG_SPI_SLAVE=y

src/main.c

@@ -1,44 +1,207 @@
 #include <zephyr/kernel.h>
-#include <zephyr/drivers/gpio.h>
 #include <zephyr/device.h>
 #include <zephyr/devicetree.h>
+#include <zephyr/drivers/gpio.h>
 #include <zephyr/drivers/spi.h>
+#include <zephyr/sys/printk.h>
 
-// SPI Master Interface on SPI1 of the rp2040
-const struct device* spi1_dev = DEVICE_DT_GET(DT_NODELABEL(spi1));
+/* 1000 msec = 1 sec */
+#define SLEEP_TIME_MS   1000
 
-// SPI but broken out
-#define	EPD_RST_PIN = 12;
-#define	EEPD_DC_PIN = 8;
-#define	EEPD_BUSY_PIN = 13;
-#define	EEPD_CS_PIN = 9;
-#define	EEPD_CLK_PIN = 10;
-#define	EEPD_MOSI_PIN = 11;
-
-// GPIO - so we can have a status LED
+/* The devicetree node identifier for the "led0" alias. */
 #define LED0_NODE DT_ALIAS(led0)
+
+#define MY_SPI_MASTER DT_NODELABEL(my_spi_master)
+#define MY_SPI_SLAVE  DT_NODELABEL(my_spi_slave)
+
+// SPI master functionality
+const struct device *spi_dev;
+static struct k_poll_signal spi_done_sig = K_POLL_SIGNAL_INITIALIZER(spi_done_sig);
+
+struct spi_cs_control spim_cs = {
+	.gpio = SPI_CS_GPIOS_DT_SPEC_GET(DT_NODELABEL(reg_my_spi_master)),
+	.delay = 0,
+};
+
+static void spi_init(void)
+{
+	spi_dev = DEVICE_DT_GET(MY_SPI_MASTER);
+	if(!device_is_ready(spi_dev)) {
+		printk("SPI master device not ready!\n");
+	}
+	if(!device_is_ready(spim_cs.gpio.port)){
+		printk("SPI master chip select device not ready!\n");
+	}
+}
+
+static const struct spi_config spi_cfg = {
+	.operation = SPI_WORD_SET(8) | SPI_TRANSFER_MSB |
+				 SPI_MODE_CPOL | SPI_MODE_CPHA,
+	.frequency = 4000000,
+	.slave = 0,
+	.cs = &spim_cs,
+};
+
+static int spi_write_test_msg(void)
+{
+	static uint8_t counter = 0;
+	static uint8_t tx_buffer[2];
+	static uint8_t rx_buffer[2];
+
+	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
+	};
+
+	// Update the TX buffer with a rolling counter
+	tx_buffer[0] = counter++;
+	printk("SPI TX: 0x%.2x, 0x%.2x\n", tx_buffer[0], tx_buffer[1]);
+
+	// Reset signal
+	k_poll_signal_reset(&spi_done_sig);
+
+	// Start transaction
+	int error = spi_transceive_async(spi_dev, &spi_cfg, &tx, &rx, &spi_done_sig);
+	if(error != 0){
+		printk("SPI transceive error: %i\n", error);
+		return error;
+	}
+
+	// Wait for the done signal to be raised and log the rx buffer
+	int spi_signaled, spi_result;
+	do{
+		k_poll_signal_check(&spi_done_sig, &spi_signaled, &spi_result);
+	} while(spi_signaled == 0);
+	printk("SPI RX: 0x%.2x, 0x%.2x\n", rx_buffer[0], rx_buffer[1]);
+	return 0;
+}
+
+// SPI slave functionality
+const struct device *spi_slave_dev;
+static struct k_poll_signal spi_slave_done_sig = K_POLL_SIGNAL_INITIALIZER(spi_slave_done_sig);
+
+static const struct spi_config spi_slave_cfg = {
+	.operation = SPI_WORD_SET(8) | SPI_TRANSFER_MSB |
+				 SPI_MODE_CPOL | SPI_MODE_CPHA | SPI_OP_MODE_SLAVE,
+	.frequency = 4000000,
+	.slave = 0,
+};
+
+static void spi_slave_init(void)
+{
+	spi_slave_dev = DEVICE_DT_GET(MY_SPI_SLAVE);
+	if(!device_is_ready(spi_dev)) {
+		printk("SPI slave device not ready!\n");
+	}
+}
+
+static uint8_t slave_tx_buffer[2];
+static uint8_t slave_rx_buffer[2];
+static int spi_slave_write_test_msg(void)
+{
+	static uint8_t counter = 0;
+
+
+	const struct spi_buf s_tx_buf = {
+		.buf = slave_tx_buffer,
+		.len = sizeof(slave_tx_buffer)
+	};
+	const struct spi_buf_set s_tx = {
+		.buffers = &s_tx_buf,
+		.count = 1
+	};
+
+	struct spi_buf s_rx_buf = {
+		.buf = slave_rx_buffer,
+		.len = sizeof(slave_rx_buffer),
+	};
+	const struct spi_buf_set s_rx = {
+		.buffers = &s_rx_buf,
+		.count = 1
+	};
+
+	// Update the TX buffer with a rolling counter
+	slave_tx_buffer[1] = counter++;
+	printk("SPI SLAVE TX: 0x%.2x, 0x%.2x\n", slave_tx_buffer[0], slave_tx_buffer[1]);
+
+	// Reset signal
+	k_poll_signal_reset(&spi_slave_done_sig);
+
+	// Start transaction
+	int error = spi_transceive_async(spi_slave_dev, &spi_slave_cfg, &s_tx, &s_rx, &spi_slave_done_sig);
+	if(error != 0){
+		printk("SPI slave transceive error: %i\n", error);
+		return error;
+	}
+	return 0;
+}
+
+static int spi_slave_check_for_message(void)
+{
+	int signaled, result;
+	k_poll_signal_check(&spi_slave_done_sig, &signaled, &result);
+	if(signaled != 0){
+		return 0;
+	}
+	else return -1;
+}
+
+/*
+ * A build error on this line means your board is unsupported.
+ * See the sample documentation for information on how to fix this.
+ */
 static const struct gpio_dt_spec led = GPIO_DT_SPEC_GET(LED0_NODE, gpios);
 
 void main(void)
 {
-    while (!device_is_ready(spi1_dev)) {
-    }
+	int ret;
 
 	if (!device_is_ready(led.port)) {
 		return;
 	}
 
-	int ret = gpio_pin_configure_dt(&led, GPIO_OUTPUT_ACTIVE);
+	ret = gpio_pin_configure_dt(&led, GPIO_OUTPUT_ACTIVE);
 	if (ret < 0) {
 		return;
 	}
 
+	spi_init();
+
+	spi_slave_init();
+
+	printk("SPI master/slave example started\n");
+
+	spi_slave_write_test_msg();
+
 	while (1) {
+		spi_write_test_msg();
 		ret = gpio_pin_toggle_dt(&led);
 		if (ret < 0) {
+            printk("Error toggling LED pin\n");
 			return;
 		}
-		k_msleep(500);
-	}
-}
+		k_msleep(SLEEP_TIME_MS);
 
+		if(spi_slave_check_for_message() == 0){
+			// Print the last received data
+			printk("SPI SLAVE RX: 0x%.2x, 0x%.2x\n", slave_rx_buffer[0], slave_rx_buffer[1]);
+
+			// Prepare the next SPI slave transaction
+			spi_slave_write_test_msg();
+		}
+	}
+    printk("SPI master/slave example finished\n");
+}