mpr121 measuring voltages from 13th sensor

Development Boards Arduino
1

On Sparkfun’s MPR121 breakout board, how can I read the rising and falling values from the proximity sensor ELE “13” as it changes in response to the varying distance between a hand and the electrode?

The data sheet and sample code can be found at http://www.sparkfun.com/products/9695

Thanks for any help.

2

:smiley:

3

Stevenh,

Here’re are four clues to get you on a more productive path in this forum:

  1. Explain clearly, with links to datasheets, what hardware you are trying to use and what you are trying to get it to do. This will reduce the “What you talkin’ 'bout, Willis?” effect.

  2. Ask a specific question or describe a specific problem. I’ve read your OP at least three times and I still don’t know what you’re asking of us.

  3. Use the “Code” button above the text input box to protect the indentation in your code, so that we can read it with less pain.

  4. Be patient! This is a user forum, not a SparkFun Tech Support service. Bumping your own post in less than 23 hours indicates that you’re not likely to be much fun to help. If you make it fun for us to help you, we will. If not, those of us here who probably can help you are more likely to find other uses for their time.

Eric

4

Eric,

Thanks for your suggestions. They are well taken. I appreciate it and I apologize.

I have rewritten and edited my original post. Hopefully it is more to the point and makes more sense.

Again thanks for letting me know.

5

Stevenh,

Section 6, Proximity Sensing on Page 7 of the [datasheet says that the 13th pin is described in [Application Note AN3893. Have you read that? I skimmed it, and it appears to me to contain a fair amount of guidance as to how to use the virtual sensor. If you’ve tried to follow those instructions and have a specific question or problem, post a detailed query.

Have Fun,

Eric](http://cache.freescale.com/files/sensors/doc/app_note/AN3893.pdf)](http://www.sparkfun.com/datasheets/Components/MPR121.pdf)

6

Thanks Eric. Yep, I read that whole doc. I think I might know what I’m doing wrong. But I’ll get back you if I’m right (or wrong…)

I can actually see the 13th electrode values vary on the graph in the Freescale eval software and reset the parameters in it as well when I am using their eval board.

Thanks again.