Arm project.

Posted by: bmihulka

Arm project. - 13/04/2000 19:00

If you've been to /. you've seen the article about the LART . It is an embeded arm system. The cool thing is they have released the cad files so you can make your own.

The site is slow right now due to /. but if you get through you can see pics of the 3x4" inch main board.

There is a FAQ here and pictures here .

Posted by: altman

Re: Arm project. - 14/04/2000 07:55

As has been pointed out before, "making your own" is not exactly possible for the average person. Soldering down 0.5mm pitch SMT stuff is hard even with the right tools, and that assumes you can get your hands on the parts in the first place - a lot of distributors won't deal with individuals/small quantity orders. Add onto that the fact that some stuff like flash and 3.3v EDO ram (as used by the SA1100) is generally on 14 week+ lead times... the PCBs will cost you around $1000 to get made one-off too.

Real homebuilt stuff is really limited to stuff you can get in 0.1" packages - which isn't anything desparately exciting anymore :(

Hugo


Posted by: bmihulka

Re: Arm project. - 14/04/2000 18:58

Of course I know it's not feasible to most everyone, but it is cool none the less.

And I alreay have a Mark I. I wish you guys would quit improving the hardware making me have to buy a new one. Just kidding, the Mark I rocks, but I think the Mark II with be totally kickass.

Brian

Posted by: altman

Re: Arm project. - 15/04/2000 06:38

The Mk2 is totally kickass ;)

I've been freezing the final versions of code in the various PICs and programmable logic devices around the main board: as well as the mk2's real time clock, the power control PIC can wake the system up automatically at preset times so you can set power-on alarms even when the unit is in the car with the ignition off (and it takes only 1mA when in this mode).

What happens is the power control PIC can wake up the main system at intervals - programmable from every 15s to 1 hour. At this wakeup time, the main system reads the RTC (or for example, might initialise ethernet and see if there's an incoming radio network connection) and then either goes back to sleep (possibly after programming a new wait time) or does a full system wakeup (ie, boots linux).

This way, we get almost full sleep functionality without having to run the whole system all the time (the whole system, with HDD spun down and screen off takes around 200mA - with HDDs on but not seeking it's 250mA, and active it's about 500mA.

Hugo