The circuit of the control unit for my showcase lighting is very simple. The core is the microcontroller MSP430G2553. A linear voltage regulator generates the required 3.3 V. The board has 2 connections for LED strips that are driven by a MOSFET. The brightness information is passed on to the ADC of the controller with a photoresistor and is evaluated there. Most I/O of the controller are required for the 5 capacitive touch fields and the feedback LEDs.
Dimming is done by PWM.
Assignment of the 5 touch fields:
- Cap_Middle: Manual lighting on/off (1s touched), reset of settings (2s touched), saving of settings (3s touched); The feedback is via the surrounding LEDs
- Cap_Up: Brighter
- Cap_Down: Darker
- Cap_Right: Upper turn-on threshold; A touch will take the current brightness
- Cap_Left: Lower turn-on threshold; A touch will take the current brightness
