Firefly PCB Board

The objective of this project is to make PCB from scratch. The Firefly boards are synchronized LED using IR sensors.

Before starting the design, my partner and I set up proper dimensional units, minimum trace, drill and pad diameters. We are very conscious about avoiding sharp turn. We tried our best to reduce the amount of vias and traces. For milling process, by following the tutorial, we milled our bottom layer without any problem. We made sure the drill bits are in the right position before milling.

Fig1: Ultiboard design of the PCB
Fig: Solderpaste Job
Fig: Potentiometer Response

Vout pin looks like a square wave with high duty cycle, and the frequency of the waveform change as we rotate the potentiometer, which is the expected behavior. 

Fig: IR sensor respnnse

We checked Trig pin output using external IR LED circuit.

At first, we get 0V for trig pin signal, but the LED still change its blinking frequency as we approach IR LED to IR transistor.

The actual result for Vout is as expected that we get a square wave with very high duty cycle, and the frequency of the square wave change as we change the potentiometer input and the IR sensor input. 

The actual result for trigger pin is at 0V at first, but after debugging, it become as expected – a saw tooth wave represent how the capacitor charge up and discharge. The trigger voltage also change as potentiometer input change and when we approach the IR LED to the 3 transistors.