This is how ready Xplained Yourself rev. 1.1.1b looks like:
It works great. I tested it with ATmega328P and ATtiny1616 as far. It can program and debug, no surprise here :)
I didn't have ferrite bead so I replaced it with piece of wire, also I didn;t have one 47u capacitor, so I replaced 1117's output cap with 1u ceramic one. I'll order them when I'll have more parts to buy.
I made few minor mistakes:
- LED name - is programming indicator not power. (I added power LED with it's resistor across C4)
- Few ground vias are not connected.
- No via is tinted.
- Few names are hidden beneath footprints.
I changed that in 1.1.1c. I also added some improvements:
- More ground fields for better screening signals.
- Power LED.
- Target voltage sensing LED.
- Test point for ATmega's reset (external programmer is needed to set clock out fuse, which is necessary for routing clock signal to CLKO pin).
- 5V protection Schottky diode. Schottky diodes have low drop - 0.3V. That means, output voltage is 4.7V, which is safe for 16MHZ and 20MHz AVRs, and should be enough.
- Signal names on silkscreen.
- I moved few traces I was afraid could touch others.
- Here are pictures of new board: