Saturday, 13 September 2014

Arduino ATTiny85 ISP Shield – PCB – Part 3

Alrighty, following on from my previous post (Arduino ATTiny85 ISP Shield - Part 2), I’ve discovered that the trace on my board for PB1 to Pin 11 was faulty (the toner transfer wasn’t all that good). This resulted in the Arduino reporting an incompatibility error when using the Arduino ISP sketch to upload a sketch to the ATTiny85.

The solution was to “draw” solder along the trace to fix the continuity.

To do that, the copper is heated with the soldering iron and the flux makes the solder to stick to the trace. I call it “drawing” because you are kinda drawing solder on with the iron. Where the copper has pitted too much, the flux doesn’t bond to the copper very well, so I had to go over the trace a couple of times to get a reasonably thick solder line.

I went over the trace a couple of times and built up a continuous line of copper across the break in the line and tested the continuity a couple of times until I got a good signal from the pin to the socket.

The next thing that I did was that I went over the entire board and patched bit’s that looked a little dodgy and where the solder fillets were not quite good enough.

Finally, I plugged in an ATTiny85 chip, connected the shield to the UNO (this time I used the Freetronics Eleven clone), connected the UNO to my PC and launched the Arduino IDE.

First, I loaded the Arduino ISP sketch to the UNO and then I changed the board to ATTiny85 (1MHz clock) and the programmer to the Arduino ISP setting and uploaded the blink sketch to the ATTiny85.

The LED all lit up at the correct time and the IDE reported the usual avrdude miss-error … I am now a happy camper. The design worked, the production of the board worked and finally, the upload of the sketch to the ATTiny85 worked too … woo-frickin-hoo!

No comments:

Post a Comment

Paypal Donations

Donations to help me to keep up the lunacy are greatly appreciated, but NOT mandatory.