Help with MPR 121 Touch Sensor

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Help with MPR 121 Touch Sensor

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johncohn
Contributor I

Folks,

    Not sure I'm posting this in the right place, if not, please point me to the right place.

I'm using an MPR121 + arduino  in a musical device and its working quite well. I'm doing trial and error changes on the settings for touch and release thresholds, auto calibration modes and debounce settings. I have it working pretty well, but I'm now trying to do some final tuning in which I'm trying to balance touch sensitivity to noise sensitivity and latency. I've read the MPR121 tutorials.. but still am struggling a bit. While I'm successfully writing the config registers, I can also read the key press register (0x5A) One thing I have not figured out how to do is to read the other internal register values (eg. the raw sense value, the current baseline, etc )   on the device and print them  to the serial monitor in the Arduino. I've tried using the same scheme to do an I2C  read for other registers.. but they always come back 0's.  Does anyone have a code fragment that shows how to read these register values..  ?

    Also.. does anyone have any suggestions on a process to optimize the the touch/release thresholds for a specific configuration ? Ive tried to work things out from the mfg tutorial at http://cache.freescale.com/files/sensors/doc/app_note/AN3889.pdf   but its a little academic.. 

   Any help / guidance on this would be much appreciated. Thanks !

-jc


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jesseg
NXP Employee
NXP Employee

Hi JC,

In this case in order for our team to provide you with this code that you required, you will need to open up a Service Request throug our Freescale.com page, the thing is that this code cannot be publish in a public site since it has licenses restrictions.

All you have to do is login to Freescale.com, go to "My Freescale" in the upper right hand corner and then click on "Enter a Service Request" that´s under the Support section.

If you have any doubts, please let me know,

JG

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bonzo
NXP Employee
NXP Employee

Go here:  https://www.sparkfun.com/products/9695

Sparkfun sells a MPR121 breakout board and there are code examples.

-Brad

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johncohn
Contributor I

OK JG.. Its request

1-937256141

thanks

-jc

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jesseg
NXP Employee
NXP Employee

Thank you JC, if you need anything else, please let me know!

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jesseg
NXP Employee
NXP Employee

Hi JC,

In this case in order for our team to provide you with this code that you required, you will need to open up a Service Request throug our Freescale.com page, the thing is that this code cannot be publish in a public site since it has licenses restrictions.

All you have to do is login to Freescale.com, go to "My Freescale" in the upper right hand corner and then click on "Enter a Service Request" that´s under the Support section.

If you have any doubts, please let me know,

JG

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