Author Topic: capacitive touch on NHD-5.0-800480FT-CTXL-CTP not working  (Read 186 times)


  • Newbie
  • *
  • Posts: 2
  • Karma: 0
    • View Profile
capacitive touch on NHD-5.0-800480FT-CTXL-CTP not working
« on: August 21, 2019, 07:49:55 AM »
I am evaluating NHD-5.0-800480FT-CTXL-CTP for a new development.
We use a NHD-5.0-800480FT-CTXL-CTP  with FT813 and control it via custom STM32 based board.
Basic API seems to work. Basic graphic seems to work as well.
However capacitive touch does not work at all. CMD_CALIBRATE will show a “dot” but will not detect any touch events.
Upon further investigation I found , that CTP_RST#  (which is connected to reset of capacitive controller) is constantly low.
Reading REG_CPURESET yields 0x00.

"Sometimes" touch will work upon restart (like 1 out of 10 tries). Any help is appreciated.

Best Regards


  • Newbie
  • *
  • Posts: 2
  • Karma: 0
    • View Profile
Re: capacitive touch on NHD-5.0-800480FT-CTXL-CTP not working
« Reply #1 on: August 23, 2019, 02:43:07 AM »
After further investigation I can report some more details:

I ordered Board (Rev. 1.0) via mouser in 07/19
In rare cases (like 1 out of 10 tries) capacitive touch will work after powering up.

After tying CTP_RST# low via soldering I can see, that the touch controler seems to work fine every time.
However FT813 will not respond to generated interrupts.  Only in rare cases everything will work after powering up.

I suspect a problem with FT813 powering up. I tried different methods of Powering of (timing of PD-Pin, ACTIVE command or CPURESET) - no luck.
One more hint: I have to use the command ACTIVE two times (as indicated in the datasheet). However all sample code only uses one such call.

Best Regards


NHD‐3.5‐320240MF‐ATXL#‐T‐1 Touch Signal

Started by jmasamotoBoard TFTs

Replies: 1
Views: 6255
Last post February 05, 2016, 08:05:40 AM
by Paul_B
NHD-5.0-800480TF-ATXL#-T and NHD-5.0-800480TF-20 Controller Board No Touch?

Started by dfanslerBoard TFTs

Replies: 5
Views: 7404
Last post May 26, 2017, 11:10:57 AM
by Saurabh_B
Arduino LCD library not working with newhaven display NHD‐0420H1Z‐FL‐GWB-3V3

Started by c2hollowBoard Character LCDs

Replies: 9
Views: 19828
Last post July 10, 2014, 08:46:06 AM
by Michael_L
NHD-FT81X-Shield & NHD-7.0-800480-CSXU-T Resitive Touch not accurate

Started by A.SuppanzBoard TFTs

Replies: 3
Views: 995
Last post February 06, 2019, 09:03:08 AM
by Ted_M
NHD‐1.5‐128128UGC3 some commands not working

Started by lordavonBoard OLEDs

Replies: 4
Views: 5432
Last post January 07, 2016, 10:58:36 PM
by lordavon