On Wed, Jan 15, 2014 at 09:59:51AM +1100, Russell Coker wrote:
Digital IO ports are required as well as a serial port. I guess it's possible to use DTR/DSR and RTS/CTS on a second serial port if a board does everything else right, only 2 digital outputs are needed.
The current systems have 2 ethernet ports, 1 for Internet access and 1 for debugging, we could survive with only 1 port if everything else is good.
The device needs to be designed for high temperatures, 70C operating temperature will do.
Allwinner ARMv7 SoCs seem to be rated at "commercial" -25 to 80 (or -40 if "extended"), however boards based on these tend to be max 70C. apparently ram is the limiting factor -> http://mail.olimex.com/forum/index.php?topic=2404.0 for example, this board is 0 to 70 -> https://www.olimex.com/Products/OLinuXino/A13/A13-OLinuXino/ and as a bonus is Open Source Hardware. similar things like the cubieboard http://docs.cubieboard.org/products/start#a10-cubieboard are harder to find temp specs for, but a comment from the manufacturer says -10 to 70. I have a couple of cubieboards (1 and 2) and they seem good, but I haven't tested anything at ambient temperatures above 30 (eg. now :). there are many other A10/A13/A20 etc. boards to choose from. millions(?) of Allwinner chips are used in small tablets. linux (including mainlining) support for the Allwinner chips is really good and active from the group at linux-sunxi.org eg. http://linux-sunxi.org/A13-OLinuXino and the best docs are probably to be found there too. HTH I don't really know what you mean by digital i/o ports (gpio? i2c? spi?) but check out the specs of the various boards and see. cubieboard ships with headers and a cable for serial console. cheers, robin