Check out the Linuxstamp over at opencircuits. This is a great project that aims to make a simple (I hope they keep it simple), small, inexpensive ARM (with MMU!) platform that can run on POE. I can’t wait to build one. It looks like a fun project.
Here are the features:
- Atmel AT91RM9200 processor (Arm9 processor with MMU)
- 32MB SDRAM (Only limited by 1x 54-TSOP SDRAM chip)
- 8MB SPI Dataflash
- 1x 10/100 Ethernet
- 1x USB host port (allows wifi adapters, flash drives and other USB devices to be used)
- 1x SD card slot
- Serial debug port access through FTDI USB/Serial converter
- JTAG port
- 2-Layer PCB design
- POE capable (48v -> 5v Power supply can be implemented on a motherboard)
They have posted the Eagle CAD files and the BOM. I really am happy to run across a design like this.
Most ARM platforms capable of running embedded Linux are fairly expensive and have lots of extra useless garbage ($150 or more). This one is supposed to be like $75 including the board. It is using a 2-layer board, but it might be OK if the groundplane is respected well. They seem to be confident it will be OK. I am a bit worried about how the RAM/Flash buses will act up with no enclosed planes, but my experience in highspeed PCB design is nonexistent, but I do try to understand the theory behind it. It will likely be OK with the traces kept short.
I am very interested in seeing this design work. Its difficult to design a computer motherboard from scratch because there is just a ton of supporting hardware and connections. I imagine it will be fun to try to get it to boot. Good thing there’s JTAG.