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I am considering a simple, low cost logging dongle for use in harsh environments: '''HW''' * Cygnal C8051F320 uProc with UART ** Marcell recommends AT91SAM7A3 * RS-232 transceiver (RS-232 level shifter, max232) * DSUB9 Serial connector * USB connector * Vreg (Sot23) * 1Mbyte SPI flash Sflash (or MMC) ** Marcell recommends MMC. In an epoxy-potted case it can be soldered without a socket. '''I only saw retail prices for larger MMCs. The 1M byte Sflash was melf or Sso8 package and $5 in 100 piece quantities and thus my interest. MMC/SD wholesale price starts from $8..$10 (64..128 Mbyte) and 256 Mbyte is just slightly above $20. The bigger memory worths the cost * 320 ? * There will be a few caps thrown in for the level shifter and regulator. '''Software''' * Identify VEMS when attached and issue data dump requests - log resulting data stream * Accepts commands when connected to host (PC or PDA) to dump data * On board USB rechargable coin cell or host powered (5V on VEMS DB9 or USB on PC/PDA) '''Conclusion''' BOM, board, assembly and testing = cheap Firmware = easy Podded in epoxy = ruggedness Anyone interested, please chime in. Cost for members should be kept in the $20 range. '''Notes''' * The group effort has (long-pending) plans on the following: ** firmware support for v3.x MMC logging GenBoard/LoggerIntegration is a bit confusing. See GenBoard/LoggerIntegration/MMC ** arm-boost is the codename of the low-cost (no fancy connectors) potted board (under development; 90 ARM uC-s are ordered for it and come in 2006 March) that is mostly sensing / networking / logging (but very restricted when it comes to power outputs). Useful for surprisingly many applications, logging is one. I suggest you join the development - first the MMC firmware _code_ than this. ** It's possible to roll an even smaller board (than arm-boost, perhaps with a different uC to save another $1 with only $900 of development task) but probably only justified if >500 can be sold. Bill's choice * currently no C skills and do not have the tools to contribute to the above (schematic or layout). ** Note that anyone who programs assembly, C is very easy and fun, and a good investment (takes little time anyway). The tools are easy to install (eg. winavr is just a 1-click installer) * I can do schematics and layout in Orcad in my sleep (I am not good, it is just too easy). * It is '''less time for me to generate it in assembler and Orcad'''. * uC: my path will use Cygnal C8051F320 as I have the tools, can code the 8051 assembler, it has UART and USB on board as well as all the clock stuff. * No need for others to support software or hardware design. * If interested, it can be for the group only as a development tool. * There is no need to produce it (or have it meet production criteria). '''Bill will probably have to do this anyway for my work.''' ** PCB+PNP production is actually not that hard/costly given that we'll have several PNP-d 2-layer boards soon to merge with (doing the PCB+PNP together saves costs). *WikiAdvert: mailto:bill@lolachampcar.com
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