Topic: touch screen sensitivity

I have a C8 and it seems like the touch screen sensitivity is degrading. I have to retouch or touch slightly to the right to get it to work. I have recalibrated several times but it doesn't seem to improve much. Is it characteristic to lose sensitivity over time? I actually do not use the touch screen much but since I moved this unit to the living room and use it as a digital picture frame now it seems to be losing its touch.

Re: touch screen sensitivity

I have used most types of Chumbys (including C8s) for years and have never seen or heard of the touch screen losing sensitivity. Perhaps someone else has had this experience?

Tar, feathers, congress. Some assembly required.

Re: touch screen sensitivity

I'm not sure how it can wear out from age, unless it's something to do with the plastic.

A resistive touchscreen is actually two transparent plastic layers coated with an electrically conductive but resistive substance, held apart by very tiny bumps.  If you hold up the display exactly right, you can actually see the little grid of bumps.  When you press the screen, you're making the two layers contact each other, and the electronics measure the electrical resistance from the edges of the screen to the place where the layers touch.

Re: touch screen sensitivity

I have a strange thing.
How can I recalibrate the touchscreen without transfer to the calibrate screen? The issue: the screen does not recognize the correct touch since yesterday. This results into a wrong button press when I touch the correct button on the screen. I cannot control the screen anymore and I cannot call the correct button to recalibrate the screen. Very mysterious. big_smile
In addition, I cannot reset the device (chumby one) to factory settings.
It seems my second chumby one dies.... sad

Re: touch screen sensitivity

You should be able to set the touchscreen to reasonable settings with a "debugchumby" script:

#!/bin/sh
echo 165,3835,3947,-3597,0 > /psp/ts_hid_settings

These are the settings for my C1 - they should be close enough to work for you.

If that works, there's a way to restore the "special options" mode from the main mode - you need to set up a dongle just like you're doing a firmware update, insert it into the device, then navigate to the hidden "pi" screen (settings->chumby info->pi), at which point a button should show up on the right side under the "clear cache" button.  I *think* you might have to unpack the zip file for this to work.

If the recalibration does not work, then it means something's gone wrong - my guess is that the microSD card is wearing out and the device is having trouble storing the settings.  You'd have to open it up and refresh or replace it.

Note also that you should be able to plug in a USB keyboard and get a console on the device, if you're inclined to use the command line to fix stuff.

6 (edited by SvenC 2016-12-31 14:20:14)

Re: touch screen sensitivity

Ah, thanks Duane. big_smile

I read about SD card problems several months ago. It's a good idea to check this one at first (there are also problems with installing zurk's FW).

Thank you and a happy new year. smile

/edit
POS. feedback
It WAS the microSDcard... After re-formatting and following instructions see link
http://forum.chumby.com/viewtopic.php?id=4338
the chumby is up and (a)live. smile
Now, the touch screen is still working (without re-calibration due to new update) and the "special option menu" is visible (incl. correct "action path". )

Thanks for the hints again. Hah smile

Re: touch screen sensitivity

Good news!

Make sure you do a USB update for the latest firmware - I think the ROM images linked from the thread are old.