May do a pic later when back home, meanwhile... I used this ESP32 board, it has RGB LED right in the middle, here is a web picture of one: https://dfimg.dfrobot.com/nobody/wiki/8a1de42ec21a99f36f69da...

Its a Fire Beetle ESP32 E V.1.0, I bought cheap <$15 don't remember when or from who anymore... The heart monitor is from a study kit (Chinese brand)

My whole set is similar (not the same, not my picture) to this: https://pic-microcontroller.com/wp-content/uploads/2018/04/B...

Enjoy !

; )