Newhaven Display Forum

Newhaven Products => TFTs => Topic started by: enjaian on July 23, 2015, 12:39:50 AM

Title: NHD-2.4-240320CF-CSXI#-F minimal wiring for power
Post by: enjaian on July 23, 2015, 12:39:50 AM
Hello. I'm trying to setup a development environment for this LCD. I read in another thread that a 2.4-240320 series LCD could tie VDD, IOVDD, and the backlight anode together at 3.1v instead of having to step down for VDD and IOVDD. I believe I did so (I've attached a CAD of the PCB with a FFC connector where the left most pin is 1 and the bottom pins are all ground) for this LCD as well, but the screen remains black when I hook it up to a voltage generator at 3.1v. I also tied RESET and IM0 to VDD to be high without any pull-ups at 3.1v. Does the problem look mechanical or did I wire something incorrectly? Thanks so much for your help with this.

Best,
Jesse Enjaian
Title: Re: NHD-2.4-240320CF-CSXI#-F minimal wiring for power
Post by: Saurabh_B on July 23, 2015, 03:18:14 PM
Hey Jesse,

I'm not seeing a connection from the backlight cathodes to ground, they seem like they're tied together but just floating.

Other things I would change is having the Reset pin attached to the MPU because it does net to be toggled for the initialization. and it seems you're going to be using 8-bit mode, you want to use DB8 - DB15 (PINS 22-29) of the display.
Title: Re: NHD-2.4-240320CF-CSXI#-F minimal wiring for power
Post by: enjaian on July 23, 2015, 05:45:25 PM
Hey Saurabh_B,

Thanks for your help. I did leave the cathodes floating on accident, but when I connected them to the ground the screen still remained black. Does the microcontroller driving the LCD need to be initialized to power the backlight? Thanks for the advice on the parallel connection and Reset pinout too!

Jesse
Title: Re: NHD-2.4-240320CF-CSXI#-F minimal wiring for power
Post by: Saurabh_B on July 24, 2015, 08:34:33 AM
The backlight should turn on so long as you have the cathodes grounded and the anode tied to Vdd. I would measure the voltage across the cathodes and anode.

With the tight area, I would recommend also checking to see if anything is getting shorted.
Title: Re: NHD-2.4-240320CF-CSXI#-F minimal wiring for power
Post by: enjaian on July 25, 2015, 04:32:22 PM
Thanks! Got it working  :D There was a short I didn't catch tucked near the FFC.

Best,
Jesse