topic MPR121 touch sensing in Linux in i.MX Processors

MPR121 touch sensing in Linux

winstonrodrigue — Thu, 21 Mar 2013 07:00:59 GMT

Dear Friends,

I am working on Freescale SABRE tablet (IMX53-SMD board). Which has a MPR121 touch sensor keyboard

with 4 keys( OPTIONS, HOME, BACK, SEARCH ). The driver for this device is already built and its present.

But I dont know how to use it. Can anyone give some idea how this touch keyboard can be used in application ?

Thanks,

Winston.

weidong_sun — Thu, 21 Mar 2013 07:29:05 GMT

Hello,Winston,

Adjust Key mapping in mx53_smd.c like the following :

static u16 smd_touchkey_martix[4] = {

KEY_OPTION, KEY_HOME, KEY_BACK, KEY_SEARCH,

};

Regard,

Weidong

winstonrodrigue — Thu, 21 Mar 2013 07:33:09 GMT

in boot log I could see these messages :

mpr121 1-005a: mpr121: config as enable 4 of electrode.

mpr121 1-005a: Mpr121 touch keyboard init success.

weidong_sun — Thu, 21 Mar 2013 07:37:19 GMT

Yes,But Original key mappling should be changed like above !

weidong

winstonrodrigue — Thu, 21 Mar 2013 07:55:04 GMT

Hey thank you Weidong.

Its working Now.....

winstonrodrigue — Thu, 21 Mar 2013 08:47:49 GMT

Hi Weidong,

Now whenever I press any of the touch keys I get the message on terminal as follows..

mpr121 1-005a: key 3 217 released

I have two questions..

1. Now the driver is configured for 4 keys, How can i do it for 12 keys. Our hardware is not yet ready but

Where exactly I need to modify the code ?

2. So is there any way that I can read the inputs from a file or something..

like when I get an interrupt I can read the file and get the readings...

Thank you.