Add ESC example and adjust build process

.gitignore

@@ -0,0 +1,2 @@
+build
+sdkconfig

CMakeLists.txt

@@ -1,6 +1,8 @@
-# The following five lines of boilerplate have to be in your project's
-# CMakeLists in this exact order for cmake to work correctly
+# The following lines of boilerplate have to be in your project's CMakeLists
+# in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.16)
 
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
-project(spincoat-plater-firmware)
+# "Trim" the build. Include the minimal set of components, main, and anything it depends on.
+idf_build_set_property(MINIMAL_BUILD ON)
+project(dshot_esc)

main/CMakeLists.txt

@@ -1,2 +1,3 @@
-idf_component_register(SRCS "spincoat-plater-firmware.c"
+idf_component_register(SRCS "spincoat-plater-firmware.c" "dshot_esc_encoder.c"
+                    PRIV_REQUIRES esp_driver_rmt
                     INCLUDE_DIRS ".")

main/spincoat-plater-firmware.c

@@ -1,6 +1,71 @@
-#include <stdio.h>
+/*
+ * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "esp_log.h"
+#include "driver/rmt_tx.h"
+#include "dshot_esc_encoder.h"
+
+#if CONFIG_IDF_TARGET_ESP32H2
+#define DSHOT_ESC_RESOLUTION_HZ 32000000 // 32MHz resolution, DSHot protocol needs a relative high resolution
+#else
+#define DSHOT_ESC_RESOLUTION_HZ 40000000 // 40MHz resolution, DSHot protocol needs a relative high resolution
+#endif
+#define DSHOT_ESC_GPIO_NUM      22
+
+static const char *TAG = "spincoat-plater-firmware";
 
 void app_main(void)
 {
+    ESP_LOGI(TAG, "Create RMT TX channel");
+    rmt_channel_handle_t esc_chan = NULL;
+    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,
+        .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
+    };
+    ESP_ERROR_CHECK(rmt_new_tx_channel(&tx_chan_config, &esc_chan));
+
+    ESP_LOGI(TAG, "Install Dshot ESC encoder");
+    rmt_encoder_handle_t dshot_encoder = NULL;
+    dshot_esc_encoder_config_t encoder_config = {
+        .resolution = DSHOT_ESC_RESOLUTION_HZ,
+        .baud_rate = 300000, // DSHOT300 protocol
+        .post_delay_us = 50, // extra delay between each frame
+    };
+    ESP_ERROR_CHECK(rmt_new_dshot_esc_encoder(&encoder_config, &dshot_encoder));
+
+    ESP_LOGI(TAG, "Enable RMT TX channel");
+    ESP_ERROR_CHECK(rmt_enable(esc_chan));
+
+    rmt_transmit_config_t tx_config = {
+        .loop_count = -1, // infinite loop
+    };
+    dshot_esc_throttle_t throttle = {
+        .throttle = 0,
+        .telemetry_req = false, // telemetry is not supported in this example
+    };
+
+    ESP_LOGI(TAG, "Start ESC by sending zero throttle for a while...");
+    ESP_ERROR_CHECK(rmt_transmit(esc_chan, dshot_encoder, &throttle, sizeof(throttle), &tx_config));
+    vTaskDelay(pdMS_TO_TICKS(5000));
+
+    ESP_LOGI(TAG, "Increase throttle, no telemetry");
+    // Commented out esc driving example, working on other stuff for now
+//    for (uint16_t thro = 100; thro < 1000; thro += 10) {
+//        throttle.throttle = thro;
+//        ESP_ERROR_CHECK(rmt_transmit(esc_chan, dshot_encoder, &throttle, sizeof(throttle), &tx_config));
+//        // the previous loop transfer is till undergoing, we need to stop it and restart,
+//        // so that the new throttle can be updated on the output
+//        ESP_ERROR_CHECK(rmt_disable(esc_chan));
+//        ESP_ERROR_CHECK(rmt_enable(esc_chan));
+//        vTaskDelay(pdMS_TO_TICKS(1000));
+//    }
 
 }