PCB Making: Customized Arduino(Atmega328)/Attiny85/555 Timer circuits

1. Customized Arduino, 12/2021
An ‘Arduino Uno’ tested on breadboard:

Arduino schematic drawn in Eagle:

2. An adjustable timer made with a 555 timer, 12/2022

3. Project done in MML using Attiny85


The previous version with FTDI chip(USB to TTL converter), however, the chip was out of stock so I just abandoned the idea of intergrating it on borad.

Self fabricting PCB etch using cupric chloride. We made this in xFab’s classes: