Update raspi pico sample implementation.

Author: jfaeh

sample-implementations/RaspberryPi_Pico/README.md

@@ -0,0 +1,33 @@
+### Project Setup
+
+To program the Raspberry Pi Pico, we use the Raspberry Pi Pico VS Code extension. 
+
+Follow these instructions to flash the example:
+
+1. Open the Raspberry Pi Pico VS Code extension and create a new **C/C++ project**.
+2. Select your board type.
+3. Enable the **I2C interface** feature.
+4. Enable **Console over USB**.
+5. Click **Create**.
+6. Copy all driver .h and .c files into the new pico project.
+7. Copy the example usage into the pico project
+8. Replace the sensirion_i2c_hal.c file with the file from the Raspberry Pi Pico sample implementation
+9. In your CMakeLists.txt, replace the add_executable block with:
+    ```cmake
+    add_executable(<project_name>
+        sen66_i2c_example_usage.c
+        sensirion_i2c.c
+        sensirion_i2c_hal.c
+        sen66_i2c.c
+        sensirion_common.c
+    )
+    ```
+10. Replace <project_name> with your project name
+11. Connect your sensor and flash the firmware.
+
+Once flashed successfully, the Raspberry Pi Pico will print sensor readings over the USB serial console.
+
+### Connecting the Sensor
+
+- SDA: GPIO4 (Pin 6)
+- SCL: GPIO5 (Pin 7)

sample-implementations/RaspberryPi_Pico/cMakeLists.txt

@@ -1,4 +1,5 @@
-#include <hardware/i2c.h>
+#include "hardware/i2c.h"
+#include "pico/stdlib.h"
 /*
  * Copyright (c) 2018, Sensirion AG
  * All rights reserved.
@@ -34,13 +35,9 @@
 #include "sensirion_config.h"
 #include "sensirion_i2c_hal.h"
 
-/*
- * INSTRUCTIONS
- * ============
- *
- * Implement all functions where they are marked as IMPLEMENT.
- * Follow the function specification in the comments.
- */
+#define I2C_PORT i2c0
+#define PIN_I2C_SDA 4
+#define PIN_I2C_SCL 5
 
 /**
  * Select the current i2c bus by index.
@@ -64,14 +61,26 @@ int16_t sensirion_i2c_hal_select_bus(uint8_t bus_idx) {
  * communication.
  */
 void sensirion_i2c_hal_init(void) {
-    /* TODO:IMPLEMENT */
+    stdio_init_all();
+
+    // I2C Initialisation. Using it at 400Khz.
+    i2c_init(I2C_PORT, 400 * 1000);
+
+    gpio_set_function(PIN_I2C_SDA, GPIO_FUNC_I2C);
+    gpio_set_function(PIN_I2C_SCL, GPIO_FUNC_I2C);
+    gpio_pull_up(PIN_I2C_SDA);
+    gpio_pull_up(PIN_I2C_SCL);
 }
 
 /**
  * Release all resources initialized by sensirion_i2c_hal_init().
  */
 void sensirion_i2c_hal_free(void) {
-    /* TODO:IMPLEMENT or leave empty if no resources need to be freed */
+    i2c_deinit(I2C_PORT);
+    gpio_set_function(PIN_I2C_SDA, GPIO_FUNC_NULL);
+    gpio_set_function(PIN_I2C_SCL, GPIO_FUNC_NULL);
+    gpio_disable_pulls(PIN_I2C_SDA);
+    gpio_disable_pulls(PIN_I2C_SCL);
 }
 
 /**
@@ -84,9 +93,10 @@ void sensirion_i2c_hal_free(void) {
  * @param count   number of bytes to read from I2C and store in the buffer
  * @returns 0 on success, error code otherwise
  */
-int8_t sensirion_i2c_hal_read(uint8_t address, uint8_t* data, uint16_t count) {
+int8_t sensirion_i2c_hal_read(uint8_t address, uint8_t* data, uint8_t count) {
     int status = i2c_read_blocking(i2c_default, address, data, count, false);
-    if (status == 0)
+
+    if (status <= 0)
         return 1;
     else
         return 0;
@@ -104,11 +114,11 @@ int8_t sensirion_i2c_hal_read(uint8_t address, uint8_t* data, uint16_t count) {
  * @returns 0 on success, error code otherwise
  */
 int8_t sensirion_i2c_hal_write(uint8_t address, const uint8_t* data,
-                               uint16_t count) {
+                               uint8_t count) {
     // I2C Default is used (I2C0).
     int status = i2c_write_blocking(i2c_default, address, data, count, true);
 
-    if (status == 0)
+    if (status <= 0)
         return 1;
     else
         return 0;