Circuit design to program Attiny85 while in circuit

Thread Starter


Joined Feb 1, 2019
I just created a new project & PCB that uses a Attiny85-20su which is a 8SOIC package.

I can't seem to find a good way to program a 8SOIC sized IC... the only possible option I could find and it's one of those clamps that clip on to a 8SOIC but I've never heard good things about them. They seem to be very unreliable.

Unless someone knows of an effective method to program these I think my only other option is to program them after soldering them to the PCB... but it seems that it could be tricky the program the Attiny after its in circuit.

My idea is to add the necessary traces to the appropriate pins to solder pads and to solder the Attiny first to the PCB and program it before adding any other components to the PCB...

Any help or opinions would be greatly appreciated


Joined Jan 27, 2019
Maybe you could bring the five lines you need for programming to a set of bridge pads and make a pogo pin jig to do the programming, then bridge the pads.

[edit: autocorrect correction]
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Joined Jul 10, 2017
I have used the 8SOIC and 16SOIC programming test clamps without any problems. Put the chip on a flat surface and push the clip down firmly before you close it. It makes very reliable contact as long as the IC's legs are clean.


Joined Aug 21, 2008
I brought the programming pins out to the edge of the boards where there were pads to which I could attach the programmer via wires.

The pads are at the bottom of the board.