CURL receive ESP32-CAM RSSI page content example

Author: GCY

ESP32-CAM MJPEG Library/ESP32-CAM Library.cpp

@@ -116,6 +116,19 @@ int ESP32_CAM::SendStream(CURL *curl_object,std::string function_url)
    return (int)return_code;
 }
 
+std::string ESP32_CAM::GetRSSI()
+{
+   std::string buffer;
+
+   curl_easy_setopt(curl_command,CURLOPT_WRITEFUNCTION,WriteCallback);
+   curl_easy_setopt(curl_command,CURLOPT_WRITEDATA,&buffer); 
+
+   if(SendStream(curl_command,std::string("/RSSI"))){
+   }  
+
+   return buffer;
+}
+
 cv::Mat ESP32_CAM::GetFrame()
 {
    cv::Mat return_data;
@@ -187,6 +200,12 @@ void* memmem(const void *buf,size_t buf_len,const void *byte_sequence,size_t byt
 }
 #endif
 
+size_t WriteCallback(void *contents, size_t size, size_t nmemb, void *userp)
+{
+    ((std::string*)userp)->append((char*)contents, size * nmemb);
+    return size * nmemb;
+}
+
 size_t CURLWriteMemoryVideoFrameCallback(void *ptr,size_t size,size_t nmemb,void *data)
 {
    if(!ptr){return 0;}

ESP32-CAM MJPEG Library/ESP32-CAM Library.h

@@ -44,6 +44,7 @@ void* VideoStreamThreadPasser(void*);
 DWORD VideoStreamThreadPasser(LPVOID);
 void* memmem(const void*,size_t,const void*,size_t);
 #endif
+size_t WriteCallback(void *contents, size_t size, size_t nmemb, void *userp);
 size_t CURLWriteMemoryVideoFrameCallback(void*,size_t,size_t,void*);
 void* CURLRealloc(void*,size_t);
 
@@ -90,6 +91,7 @@ class ESP32_CAM
 
       size_t GetFrameSize(){return frame.frame_size;}
 
+      std::string GetRSSI();
 
       cv::Mat GetFrame();
 

Firmware/.DS_Store

@@ -1,5 +1,6 @@
 #include "esp_camera.h"
 #include <WiFi.h>
+#include "define.h"
 
 //
 // WARNING!!! Make sure that you have either selected ESP32 Wrover Module,
@@ -27,6 +28,8 @@ IPAddress gateway(192, 168, 110, 1);
 
 IPAddress subnet(255, 255, 255, 0);
 
+int rssi = 0;
+
 void startCameraServer();
 
 /*
@@ -127,10 +130,11 @@ void setup() {
 
   Serial.print("Camera Ready! Use 'http://");
   Serial.print(WiFi.localIP());
-  Serial.println("' to connect");
+  Serial.println("' to connect"); 
 }
 
 void loop() {
   // put your main code here, to run repeatedly:
-  delay(10000);
+  rssi = WiFi.RSSI();
+  Serial.println(rssi);
 }

Firmware/ESP32-CAM/ESP32-CAM.ino

@@ -639,6 +639,19 @@ static esp_err_t status_handler(httpd_req_t *req){
     return httpd_resp_send(req, json_response, strlen(json_response));
 }
 
+static esp_err_t RSSI_handler(httpd_req_t *req){
+    static char json_response[1024];
+
+    char * p = json_response;
+
+    p+=sprintf(p, "%ddB", rssi);
+    *p++ = 0;
+    httpd_resp_set_type(req, "application/json");
+    httpd_resp_set_hdr(req, "Access-Control-Allow-Origin", "*");
+    return httpd_resp_send(req, json_response, strlen(json_response));
+}
+
+
 static esp_err_t index_handler(httpd_req_t *req){
     httpd_resp_set_type(req, "text/html");
     httpd_resp_set_hdr(req, "Content-Encoding", "gzip");
@@ -678,7 +691,14 @@ void startCameraServer(){
         .method    = HTTP_GET,
         .handler   = led_handler,
         .user_ctx  = NULL
-    };    
+    };
+
+    httpd_uri_t RSSI_uri = {
+        .uri       = "/RSSI",
+        .method    = HTTP_GET,
+        .handler   = RSSI_handler,
+        .user_ctx  = NULL
+    };           
 
     httpd_uri_t capture_uri = {
         .uri       = "/capture",
@@ -718,6 +738,7 @@ void startCameraServer(){
         httpd_register_uri_handler(camera_httpd, &index_uri);
         httpd_register_uri_handler(camera_httpd, &cmd_uri);
         httpd_register_uri_handler(camera_httpd, &led_uri);
+        httpd_register_uri_handler(camera_httpd, &RSSI_uri);
         httpd_register_uri_handler(camera_httpd, &status_uri);
         httpd_register_uri_handler(camera_httpd, &capture_uri);
     }

Firmware/ESP32-CAM/app_httpd.cpp

@@ -4,4 +4,6 @@
 #define RED_LED 33
 #define FLASH_LED 4
 
+extern int rssi; 
+
 #endif

Firmware/ESP32-CAM/define.h

@@ -116,6 +116,19 @@ int ESP32_CAM::SendStream(CURL *curl_object,std::string function_url)
    return (int)return_code;
 }
 
+std::string ESP32_CAM::GetRSSI()
+{
+   std::string buffer;
+
+   curl_easy_setopt(curl_command,CURLOPT_WRITEFUNCTION,WriteCallback);
+   curl_easy_setopt(curl_command,CURLOPT_WRITEDATA,&buffer); 
+
+   if(SendStream(curl_command,std::string("/RSSI"))){
+   }  
+
+   return buffer;
+}
+
 cv::Mat ESP32_CAM::GetFrame()
 {
    cv::Mat return_data;
@@ -187,6 +200,12 @@ void* memmem(const void *buf,size_t buf_len,const void *byte_sequence,size_t byt
 }
 #endif
 
+size_t WriteCallback(void *contents, size_t size, size_t nmemb, void *userp)
+{
+    ((std::string*)userp)->append((char*)contents, size * nmemb);
+    return size * nmemb;
+}
+
 size_t CURLWriteMemoryVideoFrameCallback(void *ptr,size_t size,size_t nmemb,void *data)
 {
    if(!ptr){return 0;}

examples/.DS_Store

@@ -44,6 +44,7 @@ void* VideoStreamThreadPasser(void*);
 DWORD VideoStreamThreadPasser(LPVOID);
 void* memmem(const void*,size_t,const void*,size_t);
 #endif
+size_t WriteCallback(void *contents, size_t size, size_t nmemb, void *userp);
 size_t CURLWriteMemoryVideoFrameCallback(void*,size_t,size_t,void*);
 void* CURLRealloc(void*,size_t);
 
@@ -90,6 +91,7 @@ class ESP32_CAM
 
       size_t GetFrameSize(){return frame.frame_size;}
 
+      std::string GetRSSI();
 
       cv::Mat GetFrame();