Newhaven Display Forum

Newhaven Products => TFTs => Topic started by: JonHarrison on November 01, 2017, 10:28:18 AM

Title: NHD-2.4-240320CF-CSXN#-F Brightness Adjustment
Post by: JonHarrison on November 01, 2017, 10:28:18 AM
I have been trying to adjust the brightness of this 2.4" TFT using the ST7789S controller commands without success.

As a test

    TFT_24_7789_Write_Command(0x0053); /* WRCTRLD Write CTRL display */
    TFT_24_7789_Write_Data(0x24);      /* BCTRL = 1 = brightness register active
                                          DD    = 0 = display dimming is off
                                          BL    = 1 = backlight control is on
                                       */
    for (uint16_t i = 0 ; i < 255 ;)
    {
        TFT_24_7789_Write_Command(0x0051);
        TFT_24_7789_Write_Data(i);
        TFT_delay(1000);
        i += 32;
    }

but there is no change in backlight level. Does anyone have any suggestions about what I'm doing wrong ?
Title: Re: NHD-2.4-240320CF-CSXN#-F Brightness Adjustment
Post by: Saurabh_B on November 01, 2017, 11:13:47 AM
Hello,

For our LCDs you are directly connected to the LEDs, the power is not controlled by the ST7789s.

I would recommend using an external current limiting circuit into the anode for the display.