This was the first PCB board I made, from about 1.5 years ago using Altium. It is a light sensitive light. Darker it gets, brighter it will be. Notice the wording, don’t let it confuse the LDR(light dependent resistor) too, so make LDR and LED face opposite sides if you don’t want to create an infinite loop. The photos are in reverse chronological order, and has a small joke about the loop:) .

I designed the circuit board using Altium. The microcontroller is Attiny13A, and I programmed it using C.