I had an atmel mega 16 lying around that didn’t react to the programmer anymore. This was caused because some wrong fuse bits where set (It expected an external clock). I never took the time to find a way to fix it, but being in need of more space. I’ve looked around my to see if there was something I could steal a decent clock from. After some looking around I found a device that had a PIC on it, with a decent clock signal, borrowing this clock I was able to correct this error.

The atmel mega16 has alot more space as the atmel tiny2313 (the name kind of suggest this). It has twice the amount of pins, which is nice. The best improvement is flash and sram. The mega 16 comes with 16kbyte program space (vs 2kb) and 1k of sram (vs 128b).

This is a huge improvement.  So now I had the space to get my ds1820 temperature sensor(s) to work.  Grabbing some code found via google modifying it a bit to be more correct it worked
after a fashion.

There is one nice thing on the tiny that I kind of miss on the atmega16, that is beside the 2 external interrupts it has a bus-wide interrupt. So if any of the lines of the bus changed state, I would get a interrupt, this is very nice for efficient keypads.  On the atmega16, I have just 2 interrupts.  What I did now (and it works pretty good, but it’s ugly), I just constantly poll (when the atmel is doing nothing anyway) the inputs for changes.   I need to find a nice solution for this.
Having all the space I need, in less then 2 hours I had most of the code done, and I am now going to play around making a pcb.  (suggestions for software is welcome.)

More in-depth stuff coming later…..

Qball

p.s. I am looking for some open source software that can take visual diff’s from images. anybody knows if this exists?