Showing posts from August, 2010


Today went really well, the project is almost finished!

To recap the problems we had yesterday:

The PORTC issue was the JTAG interface messing around, disabling the JTAGEN fuse solved that problem
The LCD-display had the wrong contrast wired - the example schematic was interpreted to specify 4V on Vo, while infact it wanted a voltage drop of 4V from Vdd. Wiring 1V to it solved everything nicely.

After debugging some minor bugs, adding game logic and simple inputs everything seems to work good enough to assemble to a PCB. Stay tuned!

(Sorry for the lousy photos, my iPhone cannot do any better :()

Dustin' off the old breadboard

Ah, back to university at last! Don't get me wrong, summer has been great but nothing beats Linköping.
Anyhow - about a year ago a friend wanted to create a special clock in order to measure the time it takes to empty a bottle. Initially he was going to use NAND-gates, but after showing him the price differences between using NAND-gates and an AVR we both agreed to use an ATtiny861.

Fast forward to today. We finally got to work by rigging everything and started assembling parts on my breadboard. Since I had a couple of ATmega644P laying around we upgraded to using that for now - we will see if the design will fit into an ATtiny861 in the end, I am doubtful at this stage.

I haven't used the ATmega644P a lot, but I have never had any problem with the special port functions being active by default. We had some weird problems with PORTC{2-7} outputting some sort of fast oscillating signal even though the execution was caught in a while(true);. For now we switched to using PORTC0 and…