Update README.md

Author: pschatzmann

examples/streams-memory_wav-pwm/README.md

@@ -1,7 +1,9 @@
 # Decoding a WAV file
 
-In this example we decode a WAV file into RAW output and send it to a PWM pins (e.g. on a Raspberry Pico)
- 
+In this example we decode a WAV file into RAW output and send it to a PWM pins (on a Raspberry Pico or ESP32)
+
+The WAV file has been down sampled with the help of __Audacity__ and then converted into an array with __xxd__. 
+
 MemoryStream -> AudioOutputStream -> WAVDecoder -> AudioPWM
 
 The pins depend on the Processor:
@@ -11,3 +13,5 @@ The pins depend on the Processor:
 | +       |  GPIO4         | GPIO2           |
 | -       |  GND           |                 |
 
+
+