Introduction: this project involves more about hardware than software, is my second experience (first one that works) with the design of PCBs and my first experience with Eagle.
Background: I wanted to learn to create my own PCBs. After realizing that cheap chinese 16x2 LCD need a lot of wires to be connected, I decided to create my own PCB, solder the LCD and put directly in the GPIO.
Nice! I have just brought up my first board - a tester for USB cables. I keep trying to troubleshoot stuff to see why the code won’t upload or whatever and I find that I’m using a cheap USB cable with no data wires. So this PCB just has sockets for micro USB, mini USB and USB-A (like on a computer) and tests whether current will flow between the right pairs of pins on the connector.
I just need to write the code to test for continuity between the MCU (AtMega328P-PU) pins, and light the LEDs according to whether they are conductive or not. I forgot a fair few components (I was tired when I was designing it!) so I would like to make a revision B. I also want to swap out the chip from a massive DIP package to a little surface mount one when I have the code all set. I’ll post a picture when it’s working.