Newhaven Display Forum

Newhaven Products => TFTs => Topic started by: marcelocrr on November 19, 2014, 11:10:02 AM

Title: Touch Screen - NHD-2.4-240320SF-CTXL#-FTN1
Post by: marcelocrr on November 19, 2014, 11:10:02 AM
Hi Srs,

I would like to know if it is possible to supply touch screen of NHD-2.4-240320SF-CTXL#-FTN1 display, with 3.3V instead of 5V. Is it work?

Regards.

Marcelo Rilko
Title: Re: Touch Screen - NHD-2.4-240320SF-CTXL#-FTN1
Post by: Michael_L on November 20, 2014, 09:16:09 AM
Yes it will work.  The resistive touch panels are simply voltage dividers when pressed at a certain location.  There is no IC or chip that is being powered.  Normally with 5.0V you would get near 0V when touching one end of the touch panel, and near 5.0V when touching the other end, with all the voltage levels in between representing you location.  With 3.3V, it will work the same, except it will be from 0 - 3.3V. You will need to test it to ultimately decide if it works for you.
Title: Re: Touch Screen - NHD-2.4-240320SF-CTXL#-FTN1
Post by: PeterT on November 23, 2014, 10:07:16 AM
I'm currently using the touchscreen with voltage from a Li-Ion cell (3V - 4.2V)(VBAT).  Seems to be working fine.  I just have my ADC referenced to GND and VBAT so it simply measures the touchscreen output as a ratio of VBAT.  The only variance from what marcelocrr said is that my readings only range from about 0.3V (probably due to the input buffer offset) and about 0.6VBAT (not sure why this isn't full range).