after beating my head against this for a while, and patiently waiting for sparkfun to have their serial datalogger in stock, i got this working with another LPC2148 (arm) based board, but the thing was huge. The original issue with the sparkfun datalogger was that the serial logic was in the wrong format, so i had to order an DS272 chip to convert the serial line voltage, (http://www.kmitl.ac.th/~kswichit/MAX232/MAX232.htm , datasheet here: http://datasheets.maxim-ic.com/en/ds/DS275.pdf)

this is a small 8 pin IC chip that needs no external pump capacitors like the maxim max232 would, so this was the way to go. AND it fit into the db9 shroud just fine.

there had to be a modification made to the megasquirt board to provide +5v at pin #9 of the db9, as if you were hooking up a bluetooth adapter: http://www.megamanual.com/com/bluetooth.html that's all as far as db9 modifications.

here's some ghetto pics and screenshots of the produced logs, which are still in raw format and software still have to be written to parse these.

when looking at the log, i saw at least 12 frames per second capture speed, each frame is 41 bytes. for msextra-hr. the storage medium is micro SD, the one in this unit is a 1gb card. there's a mini usb port on the edge for accessing the logs









the connector at the top is for an optional rechargeable battery, should not not want to modify the db9


logger plugged into the computer, button by the lower right is a "reset" button, which would create a new log on the card


logger shows up as a harddrive in windows, with automatically named log files.


hex dump of the created file:


one frame selected, delimited by "|*|":


41 bytes per frame apparently:


there's a lot more work to be done, mainly - modifying megatune to be able to read from one of these log files and parse the datastream and be able to save it in a normal format with all the sensors and such interpreted correctly (i.e. throttle % instead of throttle ADC, afr, instead of AFR ADC)