Feature: AI Thinker LED flash

Reduce LEDC Timer Resolution. Add LEDC error msgs

Update app_httpd.c

Increase delay for still image flash from 100ms to 150 ms.

examples/single_chip/camera_web_server/main/app_camera.c

@@ -20,6 +20,7 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 #include "esp_log.h"
+#include "driver/ledc.h"
 #include "esp_camera.h"
 #include "app_camera.h"
 #include "sdkconfig.h"
@@ -44,6 +45,32 @@ void app_camera_main ()
     gpio_config(&conf);
 #endif
 
+#ifdef CONFIG_CAMERA_MODEL_AI_THINKER
+    gpio_set_direction(LED_GPIO_NUM,GPIO_MODE_OUTPUT);
+    ledc_timer_config_t ledc_timer = {
+        .duty_resolution = LEDC_TIMER_8_BIT,  // resolution of PWM duty
+        .freq_hz = 1000,                       // frequency of PWM signal
+        .speed_mode = LEDC_LOW_SPEED_MODE,    // timer mode
+        .timer_num = LEDC_TIMER_1             // timer index
+    };
+    switch (ledc_timer_config(&ledc_timer)) {
+        case ESP_ERR_INVALID_ARG: ESP_LOGE(TAG, "ledc_timer_config() parameter error"); break;
+        case ESP_FAIL: ESP_LOGE(TAG, "ledc_timer_config() Can not find a proper pre-divider number base on the given frequency and the current duty_resolution"); break;
+        default: break;
+    }
+    ledc_channel_config_t ledc_channel = {
+        .channel    = LEDC_CHANNEL_1,
+        .duty       = 0,
+        .gpio_num   = LED_GPIO_NUM,
+        .speed_mode = LEDC_LOW_SPEED_MODE,
+        .hpoint     = 0,
+        .timer_sel  = LEDC_TIMER_1
+    };
+    if (ledc_channel_config(&ledc_channel) == ESP_ERR_INVALID_ARG) {
+        ESP_LOGE(TAG, "ledc_channel_config() parameter error");
+    }
+#endif
+
     camera_config_t config;
     config.ledc_channel = LEDC_CHANNEL_0;
     config.ledc_timer = LEDC_TIMER_0;

examples/single_chip/camera_web_server/main/app_httpd.c

@@ -17,6 +17,7 @@
 #include "esp_camera.h"
 #include "img_converters.h"
 #include "fb_gfx.h"
+#include "driver/ledc.h"
 //#include "camera_index.h"
 #include "sdkconfig.h"
 
@@ -47,6 +48,12 @@ static const char* TAG = "camera_httpd";
 #define FACE_COLOR_PURPLE (FACE_COLOR_BLUE | FACE_COLOR_RED)
 #endif
 
+#ifdef CONFIG_CAMERA_MODEL_AI_THINKER
+#define FLASH_LEDC_SPEED_MODE LEDC_LOW_SPEED_MODE
+#define FLASH_LEDC_CHANNEL LEDC_CHANNEL_1
+int flash_ledc_duty = 0; 
+#endif
+
 typedef struct {
         size_t size; //number of values used for filtering
         size_t index; //current value index
@@ -243,7 +250,21 @@ static esp_err_t capture_handler(httpd_req_t *req){
     esp_err_t res = ESP_OK;
     int64_t fr_start = esp_timer_get_time();
 
+    #ifdef CONFIG_CAMERA_MODEL_AI_THINKER
+    ledc_set_duty(FLASH_LEDC_SPEED_MODE, FLASH_LEDC_CHANNEL, flash_ledc_duty);
+    ledc_update_duty(FLASH_LEDC_SPEED_MODE, FLASH_LEDC_CHANNEL);
+    ESP_LOGI(TAG, "Activating LED duty cycle=%d", flash_ledc_duty);
+    vTaskDelay(150 / portTICK_PERIOD_MS);
+    #endif
+    
     fb = esp_camera_fb_get();
+    
+    #ifdef CONFIG_CAMERA_MODEL_AI_THINKER
+    ledc_set_duty(FLASH_LEDC_SPEED_MODE, FLASH_LEDC_CHANNEL, 0);
+    ledc_update_duty(FLASH_LEDC_SPEED_MODE, FLASH_LEDC_CHANNEL);
+    ESP_LOGI(TAG, "LED Off");
+    #endif
+    
     if (!fb) {
         ESP_LOGE(TAG, "Camera capture failed");
         httpd_resp_send_500(req);
@@ -360,11 +381,18 @@ static esp_err_t stream_handler(httpd_req_t *req){
 
     httpd_resp_set_hdr(req, "Access-Control-Allow-Origin", "*");
 
+#ifdef CONFIG_CAMERA_MODEL_AI_THINKER
+    ledc_set_duty(FLASH_LEDC_SPEED_MODE, FLASH_LEDC_CHANNEL, flash_ledc_duty);
+    ledc_update_duty(FLASH_LEDC_SPEED_MODE, FLASH_LEDC_CHANNEL);
+    ESP_LOGI(TAG, "Activating LED duty cycle=%d", flash_ledc_duty);
+#endif
+
     while(true){
 #if CONFIG_ESP_FACE_DETECT_ENABLED
         detected = false;
         face_id = 0;
 #endif
+
         fb = esp_camera_fb_get();
         if (!fb) {
             ESP_LOGE(TAG, "Camera capture failed");
@@ -490,6 +518,12 @@ static esp_err_t stream_handler(httpd_req_t *req){
         );
     }
 
+#ifdef CONFIG_CAMERA_MODEL_AI_THINKER
+    ledc_set_duty(FLASH_LEDC_SPEED_MODE, FLASH_LEDC_CHANNEL, 0);
+    ledc_update_duty(FLASH_LEDC_SPEED_MODE, FLASH_LEDC_CHANNEL);    
+    ESP_LOGI(TAG, "LED Off");
+#endif
+
     last_frame = 0;
     return res;
 }
@@ -557,6 +591,9 @@ static esp_err_t cmd_handler(httpd_req_t *req){
     else if(!strcmp(variable, "special_effect")) res = s->set_special_effect(s, val);
     else if(!strcmp(variable, "wb_mode")) res = s->set_wb_mode(s, val);
     else if(!strcmp(variable, "ae_level")) res = s->set_ae_level(s, val);
+#if CONFIG_CAMERA_MODEL_AI_THINKER
+    else if(!strcmp(variable, "flash_level")) flash_ledc_duty = val;
+#endif
 
 #if CONFIG_ESP_FACE_DETECT_ENABLED
     else if(!strcmp(variable, "face_detect")) {
@@ -620,7 +657,9 @@ static esp_err_t status_handler(httpd_req_t *req){
     p+=sprintf(p, "\"hmirror\":%u,", s->status.hmirror);
     p+=sprintf(p, "\"dcw\":%u,", s->status.dcw);
     p+=sprintf(p, "\"colorbar\":%u", s->status.colorbar);
-
+#ifdef CONFIG_CAMERA_MODEL_AI_THINKER
+    p+= sprintf(p, "\"flash_level\":%u", flash_ledc_duty);
+#endif
 #if CONFIG_ESP_FACE_DETECT_ENABLED
     p+=sprintf(p, ",\"face_detect\":%u", detection_enabled);
 #if CONFIG_ESP_FACE_RECOGNITION_ENABLED

examples/single_chip/camera_web_server/main/include/app_camera.h

@@ -119,6 +119,7 @@
 #define HREF_GPIO_NUM     23
 #define PCLK_GPIO_NUM     22
 
+#define LED_GPIO_NUM       4
 
 #elif CONFIG_CAMERA_MODEL_CUSTOM
 #define PWDN_GPIO_NUM    CONFIG_CAMERA_PIN_PWDN

examples/single_chip/camera_web_server/main/www/index_ov2640.html

@@ -531,6 +531,12 @@
                                 <label class="slider" for="colorbar"></label>
                             </div>
                         </div>
+                        <div class="input-group" id="flash-group">
+                          <label for="flash_level">Flash Level</label>
+                          <div class="range-min">0</div>
+                          <input type="range" id="flash_level" min="0" max="255" value="0" class="default-action">
+                          <div class="range-max">255</div>
+                        </div>
                         <div class="input-group" id="face_detect-group">
                             <label for="face_detect">Face Detection</label>
                             <div class="switch">

examples/single_chip/camera_web_server/main/www/index_ov3660.html

@@ -560,6 +560,12 @@
                                 <label class="slider" for="colorbar"></label>
                             </div>
                         </div>
+                        <div class="input-group" id="flash-group">
+                            <label for="flash_level">Flash Level</label>
+                            <div class="range-min">0</div>
+                            <input type="range" id="flash_level" min="0" max="255" value="0" class="default-action">
+                            <div class="range-max">255</div>
+                        </div>
                         <div class="input-group" id="face_detect-group">
                             <label for="face_detect">Face Detection</label>
                             <div class="switch">