I always find programming microcontrollers on a breadboard to be a bit of a pain. I always have to look up which pins are which, and fitting jumper wires into my AVRISPmkII is always a bit finicky. I know there are Arduino shields available for programming different chips, but they tend to be big, and you need a different shield for each different chip. I wanted a single, compact board that could be used to program a couple different AVR chips. This board can be used with the ATtiny45/65/85, the ATtiny2313, and the ATmega168/328 (of Arduino fame).

Step 1: Bill of Materials

What you will need:

- double-sided PCB & your favourite etchant

- 8 pin IC socket

- 20 pin IC socket

- 28 pin IC socket (I used 2x 14 pin sockets)

- 2x3 header pins

- 2.1mm coax power jack

- (optional) standoffs of your choosing

BOM.xlsx
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Step 2: Design

The design is straightforward - I just connected the header pins to the appropriate pins of the IC sockets. Attached below are the EagleCAD files I used.

Step 3: Board Etching

I used the toner transfer method to etch my board. I first transferred toner to one side of the board, then drilled a couple holes to help line up the other side. This was my first attempt at a double sided board, and it took a couple tries to get everything to line up correctly. Luckily, the toner comes off easily with nail polish remover if you make a mistake.

Step 4: Drilling and Soldering

The drilling and soldering is pretty straightforward. Soldering the top-side connections can seem daunting, but I didn't have any trouble. All the sockets and header pins are sitting slightly up off of the top surface, just high enough that I could get a soldering iron under them. Remember, flux is your friend!

Step 5: Finished!

Go program something!!! Works well with your modded AVRISP mkII:

https://www.instructables.com/id/Add-Power-Supply-Plug-to-AVRISP-mkII/

Introduction: AVR Programmer Board