And here's how I have the difference and summing amps set up. The difference stage uses smaller value resistors for no special reason - mostly a matter the desired RR and RC ratios vs. what was in stock.

End of the line for this iteration. While the change of grounding to a star configuration is a good plan, in my reality those new jumpers all acted as antennae.

I was able to choose the error seen at the output by moving my arms, tilting the probe, bumping a wire, etc. Putting the circuit board into a metal project-box helped, but wasn't enough. I was never able to get a consistent, repeatable set of readings.

Coming in version four: a double sided PCB, for better grounding and a more compact layout; trimmer pots, to save a bit of resistor wrangling; protection diodes, because it sucks to kill an ADC.

bigben2k sent me in here since I was asking about how to best guess in another forum ;)

I am extremely interested in your project :D

And I will be following your results closely ;)

Thanks for your work!

I knew that these graphs looked familiar...

http://www.e-insite.net/ednmag/index...=7%2F10%2F2003

good link Ben

When it comes to ways to spend a summer accomplishing nothing, there's nothing like a cute young thing in town for a summer internship. Did you know that the same groups of muscles are used for both cycling and a good pelvic thrust? Mmmmm, cross training. :cool: Ah well, now it's just fond memories and couple of jpg's.

A new motherboard and assorted parts are on the way to get this thing finished. A testing and benchmarking forum now? Cool!

Back to the geek life!

ROFL

Laughed so hard I scared the women folk. (But chose not to explain why.)

Glad to hear you are back in the saddle again. (or have I got that backwards?)

Spread the word! Tell those women folk!

Matter of fact, tell 'em I'm fit enough to ride for hours and hours at time....