Hi All,
I am trying to interface 3.5 inch lcd with iMX6qsabreauto board. Backlight is there after connecting cathode and anode per the attached datasheet for this lcd, but nothing displayed on lcd. Before this, I connected 5 inch lcd and it dispalyed some demo data from freescale.
For 3.5 inch lcd, In mxc_lcdif.c I believe it should be ok to keep below entry in fb_videomode struct:
{/*This is for 3.5inch lcd*/
/* 240x320 @ 57 Hz , pixel clk @ 27MHz */
"CLAA-WVGA", 60, 240, 320, 111111, 40, 60, 10, 10, 41, 10,
FB_SYNC_CLK_LAT_FALL,
FB_VMODE_NONINTERLACED,
0,},
// { /*This is for 5inch lcd*/
/* 800x480 @ 57 Hz , pixel clk @ 27MHz */
// "CLAA-WVGA", 60, 480, 272, 111111, 40, 60, 10, 10, 41, 10,
// FB_SYNC_CLK_LAT_FALL,
// FB_VMODE_NONINTERLACED,
// 0,},
The lower struct (commented one) we kept for a 5 inch lcd which displayed data.
Kept everything else as same as when we interfaced 5 inch lcd, 5 inch lcd display worked. Please confirm if we need to consider anything else for this new 3.5 inch LCD. Datasheet is attached.
As per data sheet I used 16 bit DB interface i.e. DB[15:0] to RGB 565 pins with MCU, and IM[3:0] = 0001. Rest we connected HSYNC, VSYNC, DOTCLK, ENABLE, VDD, VSS accordingly to MCU parallel interface pins. Rest are not connected lines.Is there a need to connect RDX,WRX,DCX, SDA etc? Please let me know if there are any inputs here.
Thanksnd regards,KK
Solved! Go to Solution.
Hi Kunal
regarding pins RDX,WRX,DCX, SDA etc, seems this lcd is multifunctional
device supporting spi,8080,rgb modes and requires additional configuration
to be set to rgb mode. Please check p.20 lcd datasheet for advice of programming
ST7789S for setting RGB Interface Control.
http://www.hpinfotech.ro/ST7789S.pdf
For i.MX6Q linux rgb lcd configuration one can look at imx6qdl-sabresd.dtsi
Best regards
igor
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Hi Igor,
Thanks for your reply. Do you mean, I need to get lcd reprogrammed for setting rgb interface? I have nil experience in this, that is why want to confirm if at all we need to get lcd reprogrammed, then should not be be coming from lcd manufacturer?
Regards,
KK
Hi Kunal
suggest to get support from lcd manufacturer
Best regards
igor