Added Uart Package Parsing

main/CMakeLists.txt

@@ -1,2 +1,2 @@
-idf_component_register(SRCS "powerpod.c" "led_ring.c"
+idf_component_register(SRCS "powerpod.c" "led_ring.c" "uart.c"
                     INCLUDE_DIRS ".")

main/uart.c

@@ -0,0 +1,109 @@
+#include "driver/uart.h"
+#include "driver/gpio.h"
+#include "esp_log.h"
+#include "esp_log_buffer.h"
+#include "freertos/idf_additions.h"
+#include "hal/uart_types.h"
+#include "nvs_flash.h"
+#include "portmacro.h"
+#include "uart.h"
+#include <stdbool.h>
+#include <string.h>
+
+static const char *TAG = "[UART]";
+static QueueHandle_t uart_cmd_queue;
+
+void init_uart(QueueHandle_t cmd_queue) {
+  uart_cmd_queue = cmd_queue;
+  uart_config_t uart_config = {// .baud_rate = 115200, // 921600, 115200
+                               .baud_rate = 921600,
+                               .data_bits = UART_DATA_8_BITS,
+                               .parity = UART_PARITY_DISABLE,
+                               .stop_bits = UART_STOP_BITS_1,
+                               .flow_ctrl = UART_HW_FLOWCTRL_DISABLE};
+
+  uart_driver_install(UART_NUM, UART_BUF_SIZE * 2, 0, 0, NULL, 0);
+  uart_param_config(UART_NUM, &uart_config);
+  uart_set_pin(UART_NUM, UART_TXD_PIN, UART_RXD_PIN, UART_PIN_NO_CHANGE,
+               UART_PIN_NO_CHANGE);
+
+  xTaskCreate(uart_read_task, "Read Uart", 4096, NULL, 1, NULL);
+}
+
+void uart_read_task(void *param) {
+  // Send all Input from Uart to the Message Handler for Parsing
+  uint8_t *data = (uint8_t *)malloc(UART_BUF_SIZE);
+  int len = 0;
+  uart_packet_t packet = {.state = STATE_START};
+  TickType_t last_byte_time = xTaskGetTickCount();
+  const TickType_t timeout_ticks = pdMS_TO_TICKS(50);
+
+  while (1) {
+    len = 0;
+    len = uart_read_bytes(UART_NUM, data, UART_BUF_SIZE, pdMS_TO_TICKS(20));
+    if (len > 0) {
+      for (int i = 0; i < len; ++i) {
+        if (parse_uart_byte(data[i], &packet)) {
+          ESP_LOGI("UART", "Paket empfangen! Länge: %d", packet.len);
+          xQueueSend(uart_cmd_queue, &packet, 0);
+        }
+      }
+      last_byte_time = xTaskGetTickCount();
+    } else { // reset message receive when there comes nothing new
+      if (packet.state != STATE_START) {
+        TickType_t now = xTaskGetTickCount();
+        if ((now - last_byte_time) > timeout_ticks) {
+          packet.state = STATE_START;
+          ESP_LOGW("UART", "Parser Timeout - Resetting State");
+        }
+      }
+    }
+  }
+}
+
+bool parse_uart_byte(uint8_t byte, uart_packet_t *p) {
+  switch (p->state) {
+  case STATE_START:
+    if (byte == START_MARKER) {
+      p->index = 0;
+      p->checksum = 0;
+      p->state = STATE_LEN;
+    }
+    break;
+
+  case STATE_LEN:
+    if (byte > MAX_PAYLOAD_SIZE || byte == 0) {
+      // corrupt length or fake start
+      p->state = STATE_START;
+    } else {
+      p->len = byte;
+      p->state = STATE_DATA;
+    }
+    break;
+
+  case STATE_DATA:
+    p->payload[p->index++] = byte;
+    p->checksum ^= byte;
+    if (p->index >= p->len) {
+      p->state = STATE_CHECKSUM;
+    }
+    break;
+
+  case STATE_CHECKSUM:
+    if (byte == p->checksum) {
+      p->state = STATE_STOP;
+    } else {
+      // CRC wrong: reset
+      p->state = STATE_START;
+    }
+    break;
+
+  case STATE_STOP:
+    p->state = STATE_START;
+    if (byte == STOP_MARKER) {
+      return true;
+    }
+    break;
+  }
+  return false;
+}

main/uart.h

@@ -0,0 +1,42 @@
+#ifndef UART_H
+#define UART_H
+
+#include "freertos/idf_additions.h"
+#include <stdbool.h>
+#include <stdint.h>
+#define UART_NUM UART_NUM_1
+#define UART_BUF_SIZE 256
+#define UART_TXD_PIN 2
+#define UART_RXD_PIN 3
+
+#define START_MARKER 0xAA
+#define STOP_MARKER 0xCC
+#define MAX_BUF_SIZE 256
+#define MAX_PAYLOAD_SIZE                                                       \
+  MAX_BUF_SIZE - 4 // Buffer overhead, Start, Len, CRC, End
+
+typedef enum {
+  STATE_START,
+  STATE_LEN,
+  STATE_DATA,
+  STATE_CHECKSUM,
+  STATE_STOP
+} parser_state_t;
+
+typedef struct {
+  uint8_t payload[MAX_PAYLOAD_SIZE];
+  uint8_t len;
+  uint8_t index;
+  uint8_t checksum;
+  parser_state_t state;
+} uart_packet_t;
+
+typedef struct {
+  uint8_t cmd;
+} uart_command_t;
+
+void init_uart(QueueHandle_t cmd_queue);
+void uart_read_task(void *param);
+bool parse_uart_byte(uint8_t byte, uart_packet_t *p);
+
+#endif