Wednesday, December 17, 2008

random ideas and stuff

Been busy IRL lately so I haven't had nearly enough time to carry out evil plans, while plans keep popping into my head.

Like, perhaps, a C-like interpreter that might actually fit in my AVR chip. Because there needs to be more stuff like that. And then I could make a standalone computer out of the evilmadscientist board.

Other random things:

- Got sniped on 208 older CPLD's by $1. They would've been 40 cents each. :P

- Needs to get something credible working soon.

- Broke down and ordered a real AVRISP mk II this morning, just in time for AVRopendous to get fixed, as far as I can tell.

- I need to solder a few things - like a male db9 plugin, a din-4 for mah ADB experiments, that kinda thing.

- It'd be fun to implement ADB in that interpreter.

- And more fun to make that interpreter a compiler, too. Running on the AVR of course.

(This is, of course, nigh impossible, or at least insane...)

Tuesday, December 9, 2008

I think my first 'real' project will be a WacomADB->USB conversion using the AVRopendous to turn the ADB tablet data into serial tablet data, which can then be picked up by Linux and Mac (TabletMagic) drivers at the very least.

There's enough documentation out there to do this - there's an ADB version of TabletMagic, and I can use that as a roadmap to getting the data out and converting it into what the serial version's data would look like.

A USB HID + newer tablet emulation might be possible, but probably quite a bit more work (as the datastream would have to be updated), and I'm not sure if Wacom would appreciate me 'borrowing' their USB device ID's, which would be needed for the native OS drivers to work. A far better target would be any standard HID extensions for tablets, which appear to be picked up by Vista at least. If MacOS and Linux can use it, that would really be the way to go. If it fits in 12K of ROM, that is...

Sunday, December 7, 2008

Weekend *cough* Update.

Been sick this weekend. (I need an antivirus upgrade. and a USB port in my head. wifi would be nice, too.)

I got my AVRopendous board plugged in - the demo works in Ubuntu 8.10 - if you put it behind a USB hub. If I wasn't sick I would have the AVR programmer code in there long before now, but it's still not in there. I'm thinking of doing one simple enhancement - it would work as a serial port *until* you hit the HWB button, allowing this + an ATmega168 to work as an arduino-type board... with bootstrapping capability.

I have a couple more boards on the way, so I can dedicate one or two to a particular role. They're quite flexible and pretty small (not as small as the FTDI USB breakouts, but more flexible ;) )

Tuesday, December 2, 2008

Back to hardware tonight...

In my quest for global domination - er, figuring out how to actually build a working board - I started playing with kicad (inspired by AVRopendous... I'm getting one of those soon) and did a first pass of USBhalfasp, my not-quite-1-layer version of the board...

I broke down and got the silver pen locally - it does, in fact, work. I'm probably going to use bus wire (where possible) for the ground and 5v planes, and then see how much I can get out of using the pen to avoid putting down too many wires. Looking at the board layout I could hypothetically get away with only using two...

[There's a bug in the layout where the 1.5k ohm pullup resistor for D+ is in parallel with the 68ohm resistor. This means that it wouldn't work. It also needs a jumper for the reset pin and a second wiring so USBasp would actually work. and most importantly, a pullup on the reset pin!]

I was hoping to have this board built today, but it took much of the evening to get the board planned out. And I think I want to add A/V outputs to this as well, assuming I can get to the PWM pins for audio...

More on this tomorrow, unless I get distracted by yet another shiny thing. Which with me could always happen...