feat(dmx): implement DMX initialization and sending functionality

components/dmx/CMakeLists.txt

@@ -1 +1 @@
-idf_component_register(SRCS "src/dmx.c" INCLUDE_DIRS "include")
+idf_component_register(SRCS "src/dmx.c" INCLUDE_DIRS "include" REQUIRES logger esp_dmx)

components/dmx/include/dmx.h

@@ -1,9 +1,15 @@
 #pragma once
 
+#include "esp_dmx.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+void init_dmx(dmx_port_t port, int pin_tx, int pin_rx);
+
+void send_dmx(dmx_port_t port);
+
 #ifdef __cplusplus
 }
 #endif

components/dmx/src/dmx.c

@@ -0,0 +1,43 @@
+#define LOG_TAG "DMX"
+
+#include <stdint.h>
+
+#include "dmx.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "logger.h"
+
+static void dmx_sender_task(void *pv_parameters) {
+  dmx_port_t port = (dmx_port_t)(intptr_t)pv_parameters;
+  TickType_t last_wake_time = xTaskGetTickCount();
+
+  while (1) {
+    send_dmx(port);
+    vTaskDelayUntil(&last_wake_time, pdMS_TO_TICKS(1000));
+  }
+}
+
+void init_dmx(dmx_port_t port, int pin_tx, int pin_rx) {
+  LOGI("Initializing DMX port %d on pin %d (TX) and %d (RX)", port, pin_tx,
+       pin_rx);
+
+  dmx_config_t config = DMX_CONFIG_DEFAULT;
+  dmx_personality_t personalities[] = {};
+  dmx_driver_install(port, &config, personalities, 0);
+
+  dmx_set_pin(port, pin_tx, pin_rx, DMX_PIN_NO_CHANGE); // RTS pin is not used
+
+  BaseType_t task_created = xTaskCreate(dmx_sender_task, "dmx_sender", 2048,
+                                        (void *)(intptr_t)port, 5, NULL);
+  if (task_created != pdPASS) {
+    LOGE("Failed to create DMX sender task for port %d", port);
+  }
+}
+
+void send_dmx(dmx_port_t port) {
+  LOGD("Sending DMX data on port %d", port);
+
+  uint8_t dmx_data[DMX_PACKET_SIZE] = {DMX_SC, 0, 0, 0, 255, 100, 0, 100, 0};
+  dmx_write(port, dmx_data, DMX_PACKET_SIZE);
+  dmx_send(port);
+}

include/README

@@ -0,0 +1,37 @@
+
+This directory is intended for project header files.
+
+A header file is a file containing C declarations and macro definitions
+to be shared between several project source files. You request the use of a
+header file in your project source file (C, C++, etc) located in `src` folder
+by including it, with the C preprocessing directive `#include'.
+
+```src/main.c
+
+#include "header.h"
+
+int main (void)
+{
+ ...
+}
+```
+
+Including a header file produces the same results as copying the header file
+into each source file that needs it. Such copying would be time-consuming
+and error-prone. With a header file, the related declarations appear
+in only one place. If they need to be changed, they can be changed in one
+place, and programs that include the header file will automatically use the
+new version when next recompiled. The header file eliminates the labor of
+finding and changing all the copies as well as the risk that a failure to
+find one copy will result in inconsistencies within a program.
+
+In C, the convention is to give header files names that end with `.h'.
+
+Read more about using header files in official GCC documentation:
+
+* Include Syntax
+* Include Operation
+* Once-Only Headers
+* Computed Includes
+
+https://gcc.gnu.org/onlinedocs/cpp/Header-Files.html

main/CMakeLists.txt

@@ -1,3 +1,3 @@
 idf_component_register(SRCS "dmx-interface.c"
                     INCLUDE_DIRS "."
-                    REQUIRES web_server)
+                    REQUIRES web_server dmx)

main/dmx-interface.c

@@ -1,5 +1,6 @@
 #include <stdio.h>
 
+#include "dmx.h"
 #include "esp_err.h"
 #include "esp_log.h"
 #include "freertos/FreeRTOS.h"
@@ -28,6 +29,8 @@ void app_main(void) {
   ESP_LOGI(TAG, "Web server started successfully");
   ESP_LOGI(TAG, "Open http://192.168.4.1 in your browser");
 
+  init_dmx(DMX_NUM_1, 21, 33);
+
   // Keep the app running
   while (1) {
     vTaskDelay(pdMS_TO_TICKS(1000));