diff --git a/examples/iot/esp32/voice_led_controller/README.md b/examples/iot/esp32/voice_led_controller/README.md
index 3745153d3..89285b574 100644
--- a/examples/iot/esp32/voice_led_controller/README.md
+++ b/examples/iot/esp32/voice_led_controller/README.md
@@ -26,8 +26,8 @@ This Arduino-based application demonstrates how to capture audio from a micropho
 * **SD Card Adapter -> ESP32**
     * CS -> IO5
     * SCK -> IO18
-    * MOSI -> IO23
-    * MISO -> IO19
+    * MOSI/DI -> IO23
+    * MISO/DO -> IO19
     * VCC -> 3.3V
     * GND -> GND
 
diff --git a/examples/iot/esp32/voice_led_controller/led_controller.ino b/examples/iot/esp32/voice_led_controller/led_controller.ino
index c227362ac..645a9c1b0 100644
--- a/examples/iot/esp32/voice_led_controller/led_controller.ino
+++ b/examples/iot/esp32/voice_led_controller/led_controller.ino
@@ -305,7 +305,8 @@ void sendAudio() {
     file.close();
     SD.end(); // Close the SD connection after reading the file
     
-    int httpCode = http.POST(jsonString);
+    http.addHeader("Content-Length", String(strlen(jsonString))); //http requests require Content-Length header to prevent http 411 error
+    int httpCode = http.POST((uint8_t*)jsonString, strlen(jsonString));
     free(jsonString);
     Serial.print(F("Http code: "));
     Serial.println(httpCode);
@@ -418,7 +419,7 @@ void setup() {
 }
 
 void loop() {
-  if (digitalRead(BUTTON_PIN) == LOW) {
+  if (digitalRead(BUTTON_PIN) == HIGH) { //check if button is pressed
     digitalWrite(LED_PIN, HIGH);
     
     // This delay is to debounce the button and allow time to speak
@@ -430,4 +431,4 @@ void loop() {
     createAudioJsonRequest();
     sendAudio();
   }
-}
\ No newline at end of file
+}