QuickStart measure volts

Kaeru no Ojisan

Hi, I am a newcomer for this forums and a quite beginner for propeller.I bought Propeller P8X32A QuickStart recently and started Propeller C Tutorials.

Please refer to Propeller C - Simple Circuits - Measure Volts.

I would like to do this using QuickStart rather than Propeller Activity Board.

Kindly advise me how to circuit and how to amend the code.

Thanks Kaeru no Ojisan

Publison

Kaeru no Ojisan wrote: »

Hi, I am a newcomer for this forums and a quite beginner for propeller.I bought Propeller P8X32A QuickStart recently and started Propeller C Tutorials.

Please refer to Propeller C - Simple Circuits - Measure Volts.

I would like to do this using QuickStart rather than Propeller Activity Board.

Kindly advise me how to circuit and how to amend the code.

Thanks Kaeru no Ojisan

Welcome to the forums !

The Quickstart board does not have an Analog to Digital converter like the Activity Board, which has a

http://www.digikey.com/product-detail/en/ADC124S021CIMM%2FNOPB/ADC124S021CIMM%2FNOPBCT-ND/755114

The Quickstart does have provisions to do Delta Sigma A/D with to addition of a few passive components. See:

http://www.parallax.com/sites/default/files/downloads/40000-Propeller-QuickStart-Guide-v1.1.pdf

Also the Apllication note is located at:

http://www.parallax.com/sites/default/files/downloads/AN008-SigmaDeltaADC-v1.0.pdf

Some more information on Delta Sigma is at:

http://www.gadgetgangster.com/tutorials/382

Hope that helps to get you started.

Feel free to ask more questions.

Publison

Tracy added a nice picture of the parts placement:

http://forums.parallax.com/showthread.php/142052-Few-QuickStart-board-specific-questions

Kaeru no Ojisan

Thank you, Publison.

I will try Quick and Cheap: 1-Bit Sigma-Delta.

Some more information on Delta Sigma is at:

http://www.gadgetgangster.com/tutorials/382

I have a question.
In the circuit shown, how to connect input signal ?

Kaeru no Ojisan

abecedarian

There are two vias near the Propeller chip with 'delta' (triangle) and 'sigma' ('E') Greek letters beneath; you can solder a two pin header there.
Then sensor (+) / output goes to the pin above 'delta' (triangle), sensor (-) goes to the other.

If your sensor's ground / VSS signal is at a different potential than the QS board ground / VSS, this could cause problems and you'd need to buffer the signal before giving it to the Propeller.

Also, the gadget gangster schematic suggested resistor values, R1=100K and R2=150K, are for reading a 5v sensor. If you're reading a 3.3v sensor, you can use 100K resistors for both.

Duane Degn

Appnote #8 is about using sigma-delta on the Propeller. (I'm pretty sure it's all in Spin and PASM.)

The Appnotes are kind of hard to find right now. I have them listed (with links) in post #3 of my index.