Newhaven Display Forum

Newhaven Products => TFTs => Topic started by: rvalor on April 24, 2019, 06:33:38 AM

Title: Display NHD-4.3-480272EF-ASXN#-T and NHD-4.3-480272EF-ASXN#-T revA
Post by: rvalor on April 24, 2019, 06:33:38 AM
Hello,

We manufacture a device based on a RPi 3 Model B and we use the display NHD-4.3-480272EF-ASXN#-T.  Recently we have updated kernel to version 4.18.20-v7+ and in some devices we are experiencing display problems... After some investigation we saw that our devices were using 2 different revisions of the display:

NHD-4.3-480272EF-ASXN#-T and NHD-4.3-480272EF-ASXN#-T revA

Both of them purchased to Mouser with the same product reference in their catalog.

The current configuration in the file /boot/config.txt regarding HDMI is:

hdmi_ignore_edid=0xa5000080
hdmi_group=2
hdmi_mode= 87

hdmi timings is:

hdmi_timings=
<h_active_pixels>   480
<h_sync_polarity>   0
<h_front_porch>      1
<h_sync_pulse>      41
<h_back_porch>      2
<v_active_lines>   272   
<v_sync_polarity>   0
<v_front_porch>      2
<v_sync_pulse>      10
<v_back_porch>      2
<v_sync_offset_a>   0
<v_sync_offset_b>   0
<pixel_rep>         0
<frame_rate>      60
<interlaced>      0
<pixel_freq>      9009000
<aspect_ratio>      3

and regarding colors, we have:

framebuffer_depth=32
framebuffer_ignore_alpha=1

we also have (but I am not sure if related...)
enable_uart=1
dtoverlay=pi3-disable-bt
dtoverlay=pi3-miniuart-bt

Please, have you any idea to overcome this problem??




Title: Re: Display NHD-4.3-480272EF-ASXN#-T and NHD-4.3-480272EF-ASXN#-T revA
Post by: Ted_M on April 25, 2019, 03:35:10 PM
The revA version of the NHD-4.3-480272EF-ASXN#-T TFT now uses a Sitronix ST7282T2 controller that replaced the  Himax HX8257-A controller on the original vesion of the 4.3" TFTs. 

Please see the Engineering change notice on our website that was sent out to customers purchasing this display: http://www.newhavendisplay.com/appnotes/datasheets/LCDs/ST7282T2.pdf (http://www.newhavendisplay.com/appnotes/datasheets/LCDs/ST7282T2.pdf)

The image below shows the RGB timing characteristics for this display. 

Please see the current datasheet for more details:http://www.newhavendisplay.com/specs/NHD-4.3-480272EF-ASXN-T.pdf (http://www.newhavendisplay.com/specs/NHD-4.3-480272EF-ASXN-T.pdf)

Best Regards,