I'm working on a pro bono project for a non-profit public-service organization. For that project I need a small microcontroller board, and I'm here to ask and see if anyone has any recommendations.

The board needs to have min. 4 programmable output pins and 12 programmable input pins, all TTL levels (other levels can be accommodated with level shifting).

There are no hard-real-time and relatively little in the way of soft-real-time requirements so I think that any processor family will do. If I had to choose I guess I'd prefer ARM but that's not essential.

As for memory requirements, if I had 64K of flash and 128K of SDRAM it's tough to imagine that not being enough.

I would like to do the software in C++ with some assembly language because I'm getting a little rusty in C++ and need to limber myself up again.

Because I haven't worked (on a paying project) in a year and a half, money is tight and I really need to keep costs as low as I can. Thus I would like something with GCC support with something like Eclipse or AVR Studio IDE or other free or low-cost IDE, and a reasonable means for debugging access like JTag or ethernet. Development platform can be either Windows or Linux, either one is fine.

An RS-232 serial port or two would be helpful but not essential.

Physical board size is totally unimportant.

So, anybody have any suggestions for lower-end SBCs I can look at that have FreeRTOS ports available and meet the I/O and IDE/debugging needs?

Thanks...

Eric / www.rkt-tech.com

I use a Zero LPC111x board for a lot of testing, I currently have it connected to a microSD card. When I got this it was under $10 with shipping, I think they're more like $15 now.

It has an LPC1114 on it. No built-in debugger.

NXP has a bunch of LPCxpresso boards that have pretty decent processors and built in debuggers. If there's a trade show near you, you can often get these for free.