add rgb check and example

README.md

@@ -15,10 +15,10 @@ See [blue-pill.md](docs/hardware/blue-pill.md) for wiring notes.
 
 - internal LED: `PC13`
 - RGB LED:
-  - `PA5` = red
-  - `PA6` = green
-  - `PA7` = blue
-  - `PA4` = drive low for the LED return path
+  - `PA0` = GND, drive low
+  - `PA1` = red
+  - `PA2` = green
+  - `PA3` = blue
 - 5-way button board:
   - `PB12` = GND, drive low
   - `PA10` = VCC, drive high
@@ -97,6 +97,8 @@ probe-rs chip list | rg STM32F103
 - `button-input` - poll the center button on `PA8`, mirror state on the LED, log transitions
 - `embassy-blinky` - minimal async blink with Embassy
 - `embassy-button` - minimal Embassy polling loop for the center button on `PA8`
+- `embassy-rgb-check` - simple RGB on/off check on `PA1`/`PA2`/`PA3`
+- `embassy-rgb` - async RGB PWM animation on `PA1`/`PA2`/`PA3`
 
 The button examples assume the 5-way board is wired like this: