pi-pico comms

dev/i2c-comms/CMakeLists.txt

@@ -34,7 +34,10 @@ pico_enable_stdio_usb(pico_i2c 1)
 
 # Add the standard library to the build
 target_link_libraries(pico_i2c
-        pico_stdlib)
+        pico_stdlib
+        pico_i2c_slave
+        hardware_i2c
+        )
 
 # Add the standard include files to the build
 target_include_directories(pico_i2c PRIVATE

dev/i2c-comms/pi_i2c.py

@@ -4,7 +4,7 @@
 
 I2C_PRIM = 0x0703
 
-# open i2c devices
+# open i2c devices (sudo apt install i2c-tools)
 i2c_fd = os.open("/dev/i2c-1", os.O_RDWR)
 
 # set the i2c address of pico
@@ -13,6 +13,17 @@
 
 # send data to pico
 data = [0x01, 0x02, 0x03]  # example data
-while (True):
-    os.write(i2c_fd, bytes(data))
-    time.sleep(1)
+while True:
+    try:
+        os.write(i2c_fd, bytes(data))
+        time.sleep(0.02)
+        print("Sent data to Pico: ", list(data))
+    except OSError:
+        print("Remote I/O Error")
+    # read data from pico
+    try:
+        incoming_data = os.read(i2c_fd, 3)  # read 3 bytes
+        time.sleep(0.02)
+        print("Received data from Pico: ", list(incoming_data))
+    except TimeoutError:
+        print("Timeout Error")

dev/i2c-comms/pi_spi.c

@@ -0,0 +1,57 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/spi/spidev.h>
+
+#define SPI_DEVICE "/dev/spidev0.0"
+#define SPI_SPEED 1000000 // 1MHz
+
+int main() {
+    int spi_fd;
+    unsigned char tx_data[] = {0xAA, 0xBB, 0xCC, 0xDD};
+    unsigned char rx_data[sizeof(tx_data)];
+
+    spi_fd = open(SPI_DEVICE, O_RDWR);
+    if (spi_fd < 0) {
+        perror("Error opening SPI device");
+        return -1;
+    }
+
+    int mode = SPI_MODE_0;
+    if (ioctl(spi_fd, SPI_IOC_WR_MODE, &mode) == -1) {
+        perror("Error setting SPI mode");
+        return -1;
+    }
+
+    if (ioctl(spi_fd, SPI_IOC_WR_MAX_SPEED_HZ, &SPI_SPEED) == -1) {
+        perror("Error setting SPI speed");
+        return -1;
+    }
+
+    struct spi_ioc_transfer transfer = {
+        .tx_buf = (unsigned long)tx_data,
+        .rx_buf = (unsigned long)rx_data,
+        .len = sizeof(tx_data),
+        .speed_hz = SPI_SPEED,
+        .bits_per_word = 8,
+    };
+
+    while (1) {
+        if (ioctl(spi_fd, SPI_IOC_MESSAGE(1), &transfer) == -1) {
+            perror("Error during SPI message transfer");
+            return -1;
+        }
+
+        printf("Received data: ");
+        for (int i = 0; i < sizeof(rx_data); i++) {
+            printf(" %02X", rx_data[i]);
+        }
+        printf("\n");
+        sleep(1);
+
+    }
+    close(spi_fd);
+    return 0;
+}

dev/i2c-comms/pico_i2c.c

@@ -1,32 +1,77 @@
 #include <stdio.h>
-#include "pico/stdlib.h"
-#include "hardware/i2c.h"
+#include <pico/stdlib.h>
+#include <pico/i2c_slave.h>
+#include <hardware/i2c.h>
 
-int main() {
+#ifndef PICO_DEFAULT_LED_PIN
+#warning blink requires a board with a regular LED
+#else
+const uint LED_PIN = PICO_DEFAULT_LED_PIN;
+#endif
+
+uint8_t outgoing_data[3] = {0x11, 0x12, 0x13}; // example data
+uint8_t incoming_data[3];
+int data_index = 0;
+
+static void i2c_slave_handler(i2c_inst_t *i2c, i2c_slave_event_t event)
+{
+    switch (event)
+    {
+    case I2C_SLAVE_RECEIVE: // master has written some data
+        for (int i = 0; i < 3; i++)
+        {
+            if (incoming_data[i] == 0x00)
+            {
+                incoming_data[i] = i2c_read_byte_raw(i2c);
+                printf("Received data %d: 0x%02X\n ", i, incoming_data[i]);
+                gpio_put(LED_PIN, 1);
+                break;
+            }
+        }
+        break;
+    case I2C_SLAVE_REQUEST: // master is requesting data
+        i2c_write_byte_raw(i2c, outgoing_data[data_index]);
+        printf("Sent data %d: 0x%02X\n ", data_index, outgoing_data[data_index]);
+        gpio_put(LED_PIN, 0);
+        data_index++;
+        if (data_index > 2)
+        {
+            data_index = 0;
+        }
+        break;
+    case I2C_SLAVE_FINISH: // master has signalled Stop / Restart
+        data_index = 0;
+        for (int i = 0; i < 3; i++)
+        {
+            incoming_data[i] = 0x00;
+        }
+        break;
+    default:
+        break;
+    }
+}
+
+int main()
+{
     stdio_init_all();
 
+#ifndef PICO_DEFAULT_LED_PIN
+#warning blink requires a board with a regular LED
+#else
+    gpio_init(LED_PIN);
+    gpio_set_dir(LED_PIN, GPIO_OUT);
+#endif
+
     // init i2c at 100kHz
     i2c_init(i2c0, 100 * 1000);
     gpio_set_function(0, GPIO_FUNC_I2C);
     gpio_set_function(1, GPIO_FUNC_I2C);
-    // i2c_pullup_en(i2c0, true);
 
     // set i2c address for pico
-    i2c_set_slave_mode(i2c0, true, 0x08);
-    // i2c_set_slave_address(i2c0, 0x08); // address should match pi code
-
-    uint8_t data[3];
-
-    while(1) {
-        // read data from i2c_pi.py
-        i2c_read_blocking(i2c0, 0x08, data, 3, true);
-
-        // process data
-        for (int i = 0; i < 3; i++) {
-            printf("Received data %d: 0x%02X\n ", i, data[i]);
-        }
-    }
+    i2c_slave_init(i2c0, 0x08, &i2c_slave_handler);
 
-    return 0;
+    while (1)
+        ;
 
+    return 0;
 }

dev/i2c-comms/pico_spi.c

@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/spi.h"
+
+#define SPI_PORT spi0
+#define PIN_MISO 16
+#define PIN_CS 17
+
+int main() {
+    stdio_init_all();
+
+    spi_init(SPI_PORT, 1000 * 1000); // init at 1MHz
+    gpio_set_function(PIN_MISO, GPIO_FUNC_SPI); // set pin to SPI mode
+
+    gpi_init(PIN_CS);
+    gpio_set_dir(PIN_CS, GPIO_OUT);
+
+    while (1) {
+        gpio_put(PIN_CS, 1); // set CS high to indiciate start of communication
+        uint8_t rx_data[4];
+        spi_read_blocking(SPI_PORT, 0, rx_data, sizeof(rx_data)); // read data from pi
+        gpio_put(PIN_CS, 0); // set CS low to indicate end of communication 
+
+        printf("Received: ");
+        for (int i = 0; i < sizeof(rx_data); i++) {
+            printf(" %02X", rx_data[i]);
+        }
+        printf("\n");
+        sleep_ms(1000);
+    }
+    return 0;
+}