PIC Questions

[Greg Hermann]

>> PIC Group,
>>
>> I was looking thru the Tech America sale flyer and I saw a cheap device,
>>probably
>> a PIC, that would turn a PC into a 'scope, sampling (at 71hz ?) and
>>playing back
>> thru the parallel port. How about someone building one so that we can
>>sample the
>> O2 sensor and MAP from a running efi system. I think it would be
>>teriffic for the
>> 332 project (or has someone already done that?). I would like to see the
>>trace of
>> the O2 sensor to determine if you can see each exhaust pulse, and if so, what
>> pieces (formula?) to monitor to determine AFR.
>>
>> The same for the MAP sensor... can you see the valves open and close???
>>Some have
>> to restrict the map sensor line to get the engine to run correctly.....
>> especially with a radical camshaft.. What reading do we use for the EFI????
>>
>The price of data acq. is dropping fast.
>ADNAV Electronics, Lake Jackson, Tx
>409-292-0988 has a 8 ch. 12 bit A/D, 2 12 bit D/A,
>8 ? I/O lines, 2 current sources and a current mirror
>for $99.  that uses printer port.
>I bought there 1st model a few years ago, was just
>1 ch. 12-bit but never have used it.  I think they
>also have kits.
>The filtering circuits and sampling times would be helpful
>to document.  The O2 signal for me has been fairly clean
>with no filtering, I get good readings hooked up straight to PIC.
>A GM TPS was very noisy.
>I was looking at O2 sensor readings for cyl. misfire, but
>but thru out all data due to lack of interest and disk space.
>There seemed to be some patterns, I would like to do something
>with DSP and rapid response micro-machined pressure sensors.
>alex

Do they do anything with thermocouple inputs, areference junction on board,
etc.??

Thinking EGT's here. Exhaust port survivable, quick response, TC's are out
there. Seems a shame to waste those holes that were put there for AIR
tubes-----!!

Regards, Greg