Update .gitignore file

.gitignore

@@ -1,2 +1,3 @@
 build
 sdkconfig
+sdkconfig.old

main/CMakeLists.txt

@@ -1,3 +1,3 @@
 idf_component_register(SRCS "spincoat-plater-firmware.c" "dshot_esc_encoder.c"
-                    PRIV_REQUIRES esp_driver_rmt esp_driver_gpio
+                    PRIV_REQUIRES esp_driver_rmt esp_driver_uart
                     INCLUDE_DIRS ".")

main/Kconfig

@@ -0,0 +1,12 @@
+menu "Pin Mapping Configuration"
+    config ESC_CTRL_PIN
+        int "ESC control GPIO pin"
+        default 22
+        help
+            This is the pin used for sending DSHOT packets to the ESC.
+    config TELEMETRY_RX_PIN
+        int "ESC telemetry uart rx pin"
+        default 27
+        help
+            This is the pin used for receiving UART telemetry from the ESC.
+endmenu

main/spincoat-plater-firmware.c

@@ -4,11 +4,13 @@
  * SPDX-License-Identifier: Unlicense OR CC0-1.0
  */
 
+#include <inttypes.h>
+
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "esp_log.h"
 #include "driver/rmt_tx.h"
-#include "driver/gpio.h"
+#include "driver/uart.h"
 #include "dshot_esc_encoder.h"
 
 #if CONFIG_IDF_TARGET_ESP32H2
@@ -16,11 +18,18 @@
 #else
 #define DSHOT_ESC_RESOLUTION_HZ 40000000 // 40MHz resolution, DSHot protocol needs a relative high resolution
 #endif
-#define DSHOT_ESC_GPIO_NUM           22
-#define DSHOT_ESC_TELEMETRY_GPIO_NUM 27
+#define GPIO_ESC_CTRL CONFIG_ESC_CTRL_PIN
+#define GPIO_ESC_RX   CONFIG_TELEMETRY_RX_PIN
+#define UART_NUM      UART_NUM_2
+
+#define ESP_INTR_FLAG_DEFAULT        0
 
 static const char *TAG = "spincoat-plater-firmware";
 
+//static QueueHandle_t gpio_evt_queue = NULL;
+static QueueHandle_t uart_queue = NULL;
+const int uart_buffer_size = (1024 * 2);
+
 rmt_encoder_handle_t dshot_encoder = NULL;
 rmt_channel_handle_t esc_chan = NULL;
 
@@ -37,7 +46,7 @@ dshot_esc_throttle_t throttle = {
  * Sends a telemetry packet at a set, constant interval
  */
 void v_telemetry_packet_func(void *pvParameters) {
-    TickType_t frequency = 1000 / portTICK_PERIOD_MS;
+    TickType_t frequency = 10 / portTICK_PERIOD_MS;
     TickType_t last_wake_time = xTaskGetTickCount();
     while(1) {
         throttle.telemetry_req = true;
@@ -63,7 +72,6 @@ void initialize_esc_throttle(void) {
     xTaskCreate(&v_initialize_esc_throttle_func, "v_init_throttle_func", 2048, NULL, 5, &v_init_throttle_handle);
     vTaskDelay(pdMS_TO_TICKS(5000));
     vTaskDelete(v_init_throttle_handle);
-    //vTaskDelay(pdMS_TO_TICKS(1000));
 }
 
 /**
@@ -73,7 +81,7 @@ void init_rmt_esc_tx(void) {
     ESP_LOGI(TAG, "Create RMT TX channel");
     rmt_tx_channel_config_t tx_chan_config = {
         .clk_src = RMT_CLK_SRC_DEFAULT, // select a clock that can provide needed resolution
-        .gpio_num = DSHOT_ESC_GPIO_NUM,
+        .gpio_num = GPIO_ESC_CTRL,
         .mem_block_symbols = 64,
         .resolution_hz = DSHOT_ESC_RESOLUTION_HZ,
         .trans_queue_depth = 10, // set the number of transactions that can be pending in the background
@@ -95,6 +103,21 @@ void init_rmt_esc_tx(void) {
     initialize_esc_throttle();
 }
 
+void init_telemetry_uart_rx(void) {
+    uart_config_t uart_config = {
+        .baud_rate = 115200,
+        .data_bits = UART_DATA_8_BITS,
+        .parity = UART_PARITY_DISABLE,
+        .stop_bits = UART_STOP_BITS_1,
+        .flow_ctrl = UART_HW_FLOWCTRL_CTS_RTS,
+        .rx_flow_ctrl_thresh = 122,
+    };
+    
+    ESP_ERROR_CHECK(uart_driver_install(UART_NUM, uart_buffer_size, uart_buffer_size, 10, &uart_queue, 0));
+    ESP_ERROR_CHECK(uart_param_config(UART_NUM, &uart_config));
+    ESP_ERROR_CHECK(uart_set_pin(UART_NUM, UART_PIN_NO_CHANGE, GPIO_ESC_RX, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE));
+}
+
 /**
  * Sends a DSHOT packet via the RMT. Make sure the RMT channel has been initialized
  * by calling *init_rmt_esc_tx()*
@@ -107,30 +130,79 @@ void send_dshot_packet(void) {
     }
 }
 
+/**
+ * Calculate one step of the crc8 and return it
+ */
+uint8_t update_crc8(uint8_t crc, uint8_t crc_seed){
+    uint8_t crc_u, i;
+    crc_u = crc;
+    crc_u ^= crc_seed;
+    for ( i=0; i<8; i++) crc_u = ( crc_u & 0x80 ) ? 0x7 ^ ( crc_u << 1 ) : ( crc_u << 1 );
+    return (crc_u);
+}
+
+/**
+ * Calculate the entire crc8 for a KISS frame and return it for validation against the
+ * transmitted crc8
+ */
+uint8_t get_crc8(uint8_t *Buf, uint8_t BufLen){
+    uint8_t crc = 0, i;
+    for( i=0; i<BufLen; i++) crc = update_crc8(Buf[i], crc);
+    return (crc);
+}
+
+/**
+ * Parse the KISS telemetry frame and check the crc8
+ * TODO: Do more with the data than print it
+ */
+void parse_telemetry(void) {
+    uint8_t frame_size = 10;
+    uint8_t data[128];
+    // get data
+    uint8_t length = uart_read_bytes(UART_NUM, data, frame_size, 100);
+    
+    uart_flush(UART_NUM);
+
+    if(length < 10) return;
+    
+    // chop out just the payload
+    uint8_t payload[128];
+    uint8_t payload_length = (frame_size - 1);
+    for(uint8_t i = 0; i < payload_length; i++) {
+        payload[i] = data[i];
+    }
+    
+    // calculate the crc8
+    uint8_t expected_crc8 = get_crc8(payload, payload_length);
+    uint8_t received_crc8 = (uint8_t) data[frame_size - 1];
+    
+    if(expected_crc8 != received_crc8) return;
+    
+    for(uint8_t i = 0; i < length; i++) {
+        printf("%d - %d\n", i, data[i]);
+    }
+    printf("--------------------\n");
+    printf("expected: %d\n", expected_crc8);
+    printf("received: %d\n", received_crc8);
+    printf("======================\n");
+}
+
 void app_main(void) {
     init_rmt_esc_tx();
+    throttle.throttle = 300;
     
-    throttle.throttle = 200;
-    xTaskCreate(&v_telemetry_packet_func, "v_telemetry_packet_func", 2048, NULL, 5, NULL);
+    xTaskCreate(&v_telemetry_packet_func, "v_telemetry_packet_func", 2048, NULL, 1, NULL);
 
-    gpio_dump_io_configuration(stdout, (1ULL << 27));
-
-    printf("==============================\n\n");
-    
-    // Testing gpio setup
-    gpio_config_t io_conf = {};
-    
-    io_conf.intr_type = GPIO_INTR_DISABLE;
-    io_conf.mode = GPIO_MODE_INPUT_OUTPUT;
-    io_conf.pin_bit_mask = (1ULL<<DSHOT_ESC_TELEMETRY_GPIO_NUM);
-    io_conf.pull_down_en = GPIO_PULLDOWN_ENABLE;
-    io_conf.pull_up_en = GPIO_PULLUP_DISABLE;
-    
-    gpio_config(&io_conf);
-    
-    gpio_dump_io_configuration(stdout, (1ULL << 27));
+    init_telemetry_uart_rx();
 
     while(1) {
         send_dshot_packet();
+        
+        uint8_t length = 0;
+        ESP_ERROR_CHECK(uart_get_buffered_data_len(UART_NUM, (size_t*)&length));
+        
+        if(length >= 10) {
+            parse_telemetry();
+        }
     }
 }