How to make a good UI panel - what TFT driver to get? - Page 1
Forum section: electronics / projects

author: MarkoAnte
author_rank: Regular Contributor
timestamp: November 30, 2015, 10:13:00 am
content: Hi,some time ago I made a UI panel using SSD1963 driven by a PIC32. I drove the display with 16 bit parallel communication (I think at pretty much max speed). The display was a 7" 800x480 tft. What I didn't like was a noticeable write "animation" any time I would change something significant on the display e.g. the back ground colour. There are a couple optimization possibility I could make to the code but the problem would still persist because the SSD1963 driver has only 1 page so there will always be some writing animations (because your writing into the same memory that the display is updating form). I was looking at maybe the RA8875 but if I wanted a 2 page memory then I would be limited to 8 bit colour. Also I have read some bed stuff about the RA8875 supposedly it has a lot of silicon bugs. I have seen that some people do this stuff with some specialized ARM processors, but I would like to keep using microchip microcontrolers because I'm know them.Does anybody know of a display module (or control ic) that is good and would support 2+ page memory and 800x480 resolution. How is this solved in every day display panels? Am I missing something really obvious?Best regards,MarkoLink to the drawing "animation" :https://youtu.be/SgtP4MZ9Hys?t=181

author: bktemp
author_rank: Super Contributor
timestamp: November 30, 2015, 01:07:33 pm
content: Quote from: MarkoAnte on November 30, 2015, 10:13:00 amYou need more video memory. That's all.If you have at least 1500k of memory you have two pages and can build up the new screen in the background while displaying the other page. Or you have to write fast enough to complete the update until the data gets send to the LCD the next time (but this is impossible at 800x480 using a PIC32 + PMP).Unfortunately PIC32 do not have an external memory interface (you can use the PMP, but it is rather slow because you need to handle any adresses above 64k using GPIO pins).There are not many LCD controllers with enough memory for several pages at 800x480. S1D13517 and S1D13513 support an external SDRAM, so you can add at least 16MBytes.ARM processors with an embedded LCD controller also have an external memory interface, so you can add a SDRAM to get enough memory for several pages.

author: Throy
author_rank: Regular Contributor
timestamp: November 30, 2015, 01:26:08 pm
content: I can't view the youtube video right now. But depending on how long it takes for you to draw, you could always turn off the backlight to your TFT display before you start drawing and turn it back on when you're finished. This could give the illusion of everything being updated at once.

author: MarkoAnte
author_rank: Regular Contributor
timestamp: November 30, 2015, 05:41:53 pm
content: I don't like the idea of using a ARM as I have 0 experience using them. I think I will go with RA8875. Has anybody worked with RA8875 before?

author: v8dave
author_rank: Regular Contributor
timestamp: December 01, 2015, 09:39:11 am
content: Want a dead easy way to get a TFT from 3.5 to 7" working with minimal effort and a dead easy programming and debugging setup (assuming you have a Windows PC that is)?Check out the GHI Electronics website. I have both 5" and 7" displays working on G120 and G400 modules. I built the attached oven controller from a G120 and a 5" Newhaven LCD. Excuse the wonky mounting in the test picture as this was the first test of the thermocouple. It's all nice and straight and been in working order for over 6 months now.www.ghielectronics.comThey now have a board that works with any of the Newhaven Displays and can plug into a number of the boards they offer or you can make your own.PS.. I have no affiliation with GHI, I am just a happy customer.