How change display resolution

Matteo — Thu, 03 Jan 2013 15:04:19 GMT

Hi all,

I want to change RGB output resolution of i.mx28 evk board. I have modified the file lcd_43wvf1g.c (attached), in particular I changed the following define to obtain a resolution of 720x480

#define DOTCLK_H_ACTIVE 720

#define DOTCLK_H_PULSE_WIDTH 62

#define DOTCLK_HF_PORCH 16

#define DOTCLK_HB_PORCH 60

#define DOTCLK_H_WAIT_CNT (DOTCLK_H_PULSE_WIDTH + DOTCLK_HB_PORCH)

#define DOTCLK_H_PERIOD (DOTCLK_H_WAIT_CNT + DOTCLK_HF_PORCH + DOTCLK_H_ACTIVE)

#define DOTCLK_V_ACTIVE 480

#define DOTCLK_V_PULSE_WIDTH 6

#define DOTCLK_VF_PORCH 9

#define DOTCLK_VB_PORCH 30

#define DOTCLK_V_WAIT_CNT (DOTCLK_V_PULSE_WIDTH + DOTCLK_VB_PORCH)

#define DOTCLK_V_PERIOD (DOTCLK_VF_PORCH + DOTCLK_V_ACTIVE + DOTCLK_V_WAIT_CNT)

The problem is that, for example, the Linux penguin is shown on the display only if I set the values of x_res to 800 and y_res to 480 in lcd_43wvf1g.c file, as shown below:

static struct mxs_platform_fb_entry fb_entry = {

.name = "43wvf1g",

.x_res = 480,

.y_res = 800,

.bpp = 32,

.cycle_time_ns = 37,

.lcd_type = MXS_LCD_PANEL_DOTCLK,

.init_panel = init_panel,

.release_panel = release_panel,

.blank_panel = blank_panel,

.run_panel = mxs_lcdif_run,

.stop_panel = mxs_lcdif_stop,

.pan_display = mxs_lcdif_pan_display,

.bl_data = &bl_data,

};

If I set the x_res value to 720 I see the display all black. Why?

Do you have any suggestion or do you have a general suggestion on how to change the display resolution?

Thanks!!

Original Attachment has been moved to: lcd_43wvf1g.c.zip

Re: How change display resolution

SergioSolis — Mon, 07 Jan 2013 15:26:29 GMT

hello Matteo,

Please take a look at the following application note regarding different display resolutions, it might help you with it. It is not made for the i.mx28 but it is certainly the same procedure:

http://cache.freescale.com/files/dsp/doc/app_note/AN3974.pdf

Re: How change display resolution

mallikarjunared — Wed, 26 Feb 2014 04:59:10 GMT

Hai Fabiani,

I also had the same problem (i.e, configure 320x240 lcd). Have you solved the problem. If so, let me know how?

Thanks & Regards

Mallikarjuna Reddy

topic Re: How change display resolution in i.MX Processors

How change display resolution

Re: How change display resolution

Re: How change display resolution