ECU/MAX232 noise

[Barry Tisdale]

I'm sure that getting your power from the PC would be the best way to go.
My interface uses a 7812, in turn feeding a 7805; max current draw is 33ma
with this setup.  Not sure what the serial interface pins will supply.

My circuit gets its power from a small gel cell 12v battery that's
connected via a diode to the 'ignition ON' feed - its purpose is so the
inverter used to power my laptop (no battery in it) can record data through
an engine crank & startup.  W/O this aux battery, the laptop would reboot
while cranking engine.

NOW I can log data w/ my serial interface & software (bargraphing some
data), convert the resultant text file to Diacom format & use Diacom
software to view the data - the best of both worlds!

>From start to finish, this project was about six months, but it finally
works well.

Barry - Sy#26