Newhaven Display Forum

Newhaven Products => TFTs => Topic started by: pierrelgcb on March 09, 2016, 04:22:56 AM

Title: NHD-5.0-800480TF-ATXL#-CTP HV mode
Post by: pierrelgcb on March 09, 2016, 04:22:56 AM
Hello,

I use NHD-5.0-800480TF-ATXL#-CTP with Android 5.0. I could configure screen size to reach TFT active area but image is medium quality. I have some blinking pixels or red/blue pixels. I would like to try another synchronization mode.

Thanks to this post, http://www.newhavendisplay.com/NHD_forum/index.php/topic,1091.msg2582/topicseen.html#msg2582 (http://www.newhavendisplay.com/NHD_forum/index.php/topic,1091.msg2582/topicseen.html#msg2582) , I think the display is DE mode. How could I change to HV mode ?

Regards, Pierre
Title: Re: NHD-5.0-800480TF-ATXL#-CTP HV mode
Post by: Paul_B on March 09, 2016, 09:06:56 AM
Morning Pierre,

NHD-5.0-800480TF-ATXL# uses the OTA7001A source driver and OTD9960A gate driver, is defaulted as SYNC mode, and its PCLK latched data is on the rising edge.

To change to DE+SYNC mode, R17 needs to be shorted and R18 needs to be open. It comes default as R17 shorted and R18 open.

To change the PCLK polarity to falling edge, R19 needs to be shorted and R20 needs to be open. It comes default as R19 open and R20 shorted.

Based on what you are experiencing with the blinking pixels it sounds like you need to change the PCLK polarity to falling edge.

Hope this helps!
Title: Re: NHD-5.0-800480TF-ATXL#-CTP HV mode
Post by: pierrelgcb on March 10, 2016, 03:01:55 AM
Hello Paul,

Thanks for your reply. Unfortunately, I'm little confused. When I read first line, I understand default is SYNC mode. On my default PCB, R18 is open and R17 is shorted. On second line, you write it equals DE+SYNC mode. Which modes are :
- R18(open)/R17(shorted) ?
- R18(shorted)/R17(open) ?

About PCLK polarity, R19 and R20 are both connected on my PCB. I took a photo (pcb.jpg) of the display PCB to be sure we are talking about the same resistors.

Edit : Note : On photo, I switched R8/R7 resistors (before you edit your post). Other components are default.

Thank you for your support  :), Pierre

ps : the captcha is really hard to read !
Title: Re: NHD-5.0-800480TF-ATXL#-CTP HV mode
Post by: Paul_B on March 10, 2016, 08:30:53 AM
Morning Pierre,

The photos defiantly help, it appears you are utilizing an older Rev of NHD-5.0-800480TF-ATXL#-CTP.

Your display stock will be configured the following way:

Defaulted as SYNC mode, and its PCLK latched data on the rising edge.

R7 & R8 are what changes the mode.  It comes default as R7 open and R8 shorted.  To change to DE+SYNC mode, R7 needs to be shorted and R8 needs to be open.

R9 & R10 are what changes the PCLK polarity.  It comes default as R9 shorted and R10 open.  To change the PCLK polarity to falling edge, R9 needs to be open and R10 needs to be shorted.


Title: Re: NHD-5.0-800480TF-ATXL#-CTP HV mode
Post by: pierrelgcb on March 11, 2016, 07:54:08 AM
Morning Paul  ;D

Hard changing PCLK polarity (R9-R10) solved the problem ! Image is good quality now. I was sure to software invert PCLK but it wasn't...

Many thanks!
Pierre
Title: Re: NHD-5.0-800480TF-ATXL#-CTP HV mode
Post by: Paul_B on March 11, 2016, 08:00:41 AM
Awesome, enjoy your new display!