Olimex have released USD$59 Atmel ARM7 board

[Dingo]

I've been waiting a while for this one.

Olimex (Bulgarian supplier of cheap but very high quality microcontroller boards and the like) have finally released for sale an Atmel (they make AVRs) ARM7 board.

The cost is USD$59 plus you'll need an ARM J-TAG for USD$19 and postage to Australia is USD$9. Still it is pretty great value.

The currently available board supports USB and has an SD Card socket amongst other things. The next one to be released soon has been listed as

"SAM7-EA2 - development board for AT91SAM7A2 ARM7 microcontroller with Ethernet and uClinux support"

I so want my bots to run linux and play mp3s and calulate floating point maths and talk over eth0 and USB.......<droooool>....

The link to the current one is here
www.olimex.com/dev/sam7-p64.html

and Olimex generally

www.olimex.com/dev/index.html

[Dingo]

Please note the board mentioned above will not run uCLinux, maybe eCos.

Here is a copy of a post I made at www.at91.com

Having spent all afternoon searching the internet for the current infomation about Atmel ARMs and uCLinux it seems the generally agreed to amount of static RAM needed is in excess of at the very least 300Kb. More like 512Kb when including TCP/IP stacks etc.

So the only SAM7 parts that can run uClinux are SAM7A1 and SAM7A2 when coupled with external RAM in the order of 512kb or more.

To this end no other current SAM7 parts have anywhere near that amount of internal SRAM so to run uCLinux (16 and 32Kb) so you need external RAM.

The SAM7A2 has EBI which allows 4 lines multiplexed to allow up to 6 MB of external RAM to be added on top of the internal stack. The preliminary datasheets for the SAM7A3 make no mention of EBI nor of adding external RAM. Without it, it is unlikely any useful uCLinux can run. (A very small version might but it wouldn't have TCP/IP stack nor ROMFS etc).

For other SAM7 parts:
The opensource OS eCos can run with a minimum of 60Kb. Thus SAM7 parts with 64Kb (just enough) or more *could* run it. As far as I can tell, eCos requires each app to be compiled with the OS and then flashed into the platform as one block of code.

Of course the AT91RM9200 can take external RAM but it runs at 150+Mhz (know how to design great PCB before spending money here) and is twice the price of an SAM7A2.

So my conclusion is the SAM7A1 (4 kb of internal RAM) or the SAM7SAM2 (16kb of internal RAM) are the best (only?) SAM7 options to run uCLinux. You will of course need to add some RAM.

Note: Olimex are planning on releasing a board in September that is a SAM7A2 running uCLinux and capable of ethernet.