ATMEGA328AU bootloader and programming sketches

I needed to update how to boot-load and program ATMEGA328AU chips.

Attached is a brief rundown on how-to.

I hope you find it useful.

PDF

UV Exposure Box rises

Skeleton



Boxed



Painted, wired and mounted



Tested



Timing of 270 seconds seems about right.

First double sided board

Developing.



Etching setup.



Rivets for vias. 0.6 x 0.8mm.



Resistor and LED, 0605.



uC left to solder then clean off flux and test.



A couple of issues with developing process. Going to try some heat.

Test etching, getting closer!

Timing now to 270 seconds under UV.
32 pin TQFP footprint came out fairly clean.





Accurate control of etching temperature is critical.

Etching

Test etching.











Some work to do on the quality of printing and laminate photo transfer timing.