Interfacing with a HT150x02-100 TFT Screen - Page 1
Forum section: electronics / general

author: CM800
author_rank: Frequent Contributor
timestamp: April 13, 2014, 07:52:42 pm
content: Hello, I recently got hold of a HT150x02-100 TFT Screen.Most ones you can't find a datasheet, but for this one, i managed to:Here.I kind of understand the information, however i do not understand how i would set about working with it.Is anyone able to explain it to me or link me to the explanation of this protocol (im using the 20 pin connector on there)My main plan is first just get the screen to go green.Thanks!

author: Skimask
author_rank: Super Contributor
timestamp: April 13, 2014, 07:57:12 pm
content: Re: Page 13 of that datasheet...Are you up to sending data at a minimum 54Mhz data rate?

author: CM800
author_rank: Frequent Contributor
timestamp: April 13, 2014, 09:00:47 pm
content: Quote from: Skimask on April 13, 2014, 07:57:12 pmWell i guess, got to learn some how.Could you not just read it constantly from memory, modify it when needed. or one of those fancy TFT driver chips?

author: Skimask
author_rank: Super Contributor
timestamp: April 13, 2014, 09:08:39 pm
content: Want some free advice?...Don't...Think about it. 54Mhz minimum data rate going out to the LCD panel. At 1 bit color depth (eg. black/white), that's at 96KB of ram just for the video information.Throw in 24bit color depth, over 2MB of 'video' ram alone.50 frames/sec @ 2MB = 112.5MB/sec, at the MINIMUM clocking rate. And that 'video' ram most likely has to be dual port as well.How deep is your FPGA skillset?Not trying to talk you out of it, but I'd highly doubt you'll be able to find somebody that's willing to hold your hand and walk you thru the process of designing, building, and programming something to drive this panel.

author: CM800
author_rank: Frequent Contributor
timestamp: April 13, 2014, 09:18:07 pm
content: Quote from: Skimask on April 13, 2014, 09:08:39 pmI don't really want my hand held, just useful links, maybe just a little help on understanding how it works.I have to learn somewhere and somehow.

author: Skimask
author_rank: Super Contributor
timestamp: April 13, 2014, 09:35:01 pm
content: Then Google is your friend.LVDS interfaces, relatively high speed data transfer methods, high voltage required for the back panel itself...it's all out there.

author: CM800
author_rank: Frequent Contributor
timestamp: April 13, 2014, 10:36:03 pm
content: Quote from: Skimask on April 13, 2014, 09:35:01 pmWell alright then, i shall have a look into that.Any more information from anyone is very welcome!

author: miguelvp
author_rank: Super Contributor
timestamp: April 14, 2014, 03:58:52 am
content: http://www.ebay.com/bhp/lcd-panel-controllerBut you might need to get the programmer if your display is not supported. Of course those controllers won't do HDCP so you can't use the display to view copy protected content. They also won't read the EDID nor provide it to your the hdmi connector.I've seen people solder directly to the LCD board using twisted pair cables and drive it with an FPGA. If going that route, I would use a discarded ethernet cable for the twisted pair, or purchase an LVDS connector from ebay.

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: April 14, 2014, 05:27:55 am
content: Sounds interesting, but hard, but seems like you're going to dive in and learn something. That ain't bad even if you never make it do what you'd intended. At the least you'll learn a thing or two. LVDS is kinda interesting in itself.I saw some vids on using FPGA to drive a display. Good luck on it, I've been wanting to know more about this kind of project as there are so many cheap electronics on ebay with e-paper/e-ink and TFT, etc. And they cost much less than just buying a display from the display makers but repurposing is not always possible as I've been learning.

author: Dago
author_rank: Frequent Contributor
timestamp: April 14, 2014, 06:11:51 am
content: I say if you want to learn FPGAs then just go for itDriving a TFT display without a controller is a very nice project for learning to use FPGAs. I did something very similar for my first FPGA project as well, driving a PlayStation portable display (which are very cheap from eBay):http://www.dgkelectronics.com/fpga-based-playstation-portable-display-driver/

author: miguelvp
author_rank: Super Contributor
timestamp: April 14, 2014, 06:25:35 am
content: Some nice info about LVDS panels:Using 24-bpp LVDS Panels with Intel® Mobile Chipsets for Embedded Applicationshttp://www.intel.com/design/intarch/papers/315975.pdfFPGA example:http://g3nius.org/lcd-controller/I would use twisted pair instead of straight wires like he did.But be careful with the inverter for the back light, It uses high voltage to power those CCFL (cold cathode fluorescent lamp) tubes.

author: CM800
author_rank: Frequent Contributor
timestamp: April 14, 2014, 08:53:14 am
content: Thankyou for all that info, im gonna have a look at it as soon as i can (about to go on a trip for a few days)

author: amyk
author_rank: Super Contributor
timestamp: April 14, 2014, 09:04:20 am
content: Interesting that the datasheet specifies a minimum frequency, but no maximum clock period...some advice found heresuggests that it may still work fine at much lower clock frequencies, but it may also not --- depends if there is dynamic circuitry in the row/column drivers or not.