examples : add pinout info for the MCU examples

examples/esp32-rx/README.md

@@ -22,15 +22,15 @@ The received messages are optionally displayed on the attached OLED display.
 
 ### Analog Microphone
 
-| EPS32   | Mic       |
+| MCU     | Mic       |
 | ------- | --------- |
 | GND     | GND       |
 | 3.3V    | VCC / VDD |
 | GPIO 35 | Out       |
 
-### Digital Microphone
+### Digital (I2S) Microphone
 
-| EPS32   | Mic         |
+| MCU     | Mic         |
 | ------- | ----------- |
 | GND     | GND         |
 | 3.3V    | VCC / VDD   |
@@ -38,9 +38,9 @@ The received messages are optionally displayed on the attached OLED display.
 | GPIO 33 | Data / DOUT |
 | GPIO 25 | LRCL        |
 
-### I2C Display
+### I2C Display (optional)
 
-| EPS32   | Display     |
+| MCU     | Display     |
 | ------- | ----------- |
 | GND     | GND         |
 | 3.3V    | VCC / VDD   |

examples/esp32-rx/esp32-rx.ino

@@ -35,6 +35,35 @@
 //
 // Sketch: https://github.com/ggerganov/ggwave/tree/master/examples/esp32-rx
 //
+// ## Pinout
+//
+// ### Analog Microphone
+//
+// | MCU     | Mic       |
+// | ------- | --------- |
+// | GND     | GND       |
+// | 3.3V    | VCC / VDD |
+// | GPIO 35 | Out       |
+//
+// ### Digital (I2S) Microphone
+//
+// | MCU     | Mic         |
+// | ------- | ----------- |
+// | GND     | GND         |
+// | 3.3V    | VCC / VDD   |
+// | GPIO 26 | BCLK        |
+// | GPIO 33 | Data / DOUT |
+// | GPIO 25 | LRCL        |
+//
+// ### I2C Display (optional)
+//
+// | MCU     | Display   |
+// | ------- | --------- |
+// | GND     | GND       |
+// | 3.3V    | VCC / VDD |
+// | GPIO 21 | SDA       |
+// | GPIO 22 | SCL       |
+//
 
 // Uncomment the line coresponding to your microhpone
 #define MIC_ANALOG