Add check to Arduino sketch to wait with sending data

Author: sebromero

libraries/Portenta_Camera/examples/CameraCaptureRawBytes/CameraCaptureRawBytes.ino

@@ -4,19 +4,22 @@ CameraClass cam;
 uint8_t fb[320*240];
 
 void setup() {
-
-  Serial.begin(921600);
+  Serial.begin(921600);  
 
   // Init the cam QVGA, 30FPS
   cam.begin(CAMERA_R320x240, 30);
 }
 
 void loop() {
   // put your main code here, to run repeatedly:
-  if (Serial) {
-    // Grab frame and write to serial
-    if (cam.grab(fb) == 0) {
-       Serial.write(fb, 320*240);
-    }
+  
+  // Wait until the receiver acknowledges
+  // that they are ready to receive new data
+  while(Serial.read() != 1){};
+  
+  // Grab frame and write to serial
+  if (cam.grab(fb) == 0) {
+     Serial.write(fb, 320*240);       
   }
+  
 }