SideBySide controlboard for TFT display (DIY project) - Page 1
Forum section: electronics / beginners

author: ccamacho
author_rank: Newbie
timestamp: April 25, 2018, 05:18:26 pm
content: Hello everyone,First, congratulate the community for this awesome site!.I'm working on a DIY project to have a Side By Side display for building up a VR goggle.This is the main diagram of what I will like to build.I'm not sure how hard would be to build this, I already have some ideas.For the video switch I can:Convert the HDMI signal to composite by using something like:Now use a solid state video switcher like the one described in here:https://www.engadget.com/2007/03/13/how-to-make-a-solid-state-a-v-switcher/Now for the screen, I'll like to use a cheap 3.5" TFT display with the highest resolution possible (from aliexpress from around 11 USD).Now, here is the part I'm not finding enough information.How to create a SBS signal to display it on the screen?Maybe is it possible to reprogram a RTD2660H HDMI/VGA/NTSC/PAL Driver Board to to what I need?Any information is welcomed,Thanks!

author: ovnr
author_rank: Frequent Contributor
timestamp: April 25, 2018, 06:00:12 pm
content: I take it you want to take a HDMI signal, convert it to composite, then switch between the HDMI-composite and another composite source to display that on two small TFTs? That bit is fine, but it'll of course look like shit because composite video is shit.But since you're talking about side by side, are you thinking of the various 3D formats used, so that you can get a proper 3D effect - and not just display the same image on both screens? Because that would increase the difficulty waaaay beyond anything easily hacked together.If you just want the same image on both screens, you should be able to just parallel the screens and hook them up to the same composite to LCD converter board you're using.Also, video quality would be better if you instead converted composite to HDMI and used a HDMI switch.

author: ccamacho
author_rank: Newbie
timestamp: April 25, 2018, 07:41:40 pm
content: Ok,So, let's take away the switch, the first thing would be then to use a control board like this oneNow, is it possible to output SBS image from it? I just need the same image twice, the thing is that if using two screens I'll need to use two (2) 1.8" screens (Do you know any good quality/hi resolution screens I can use?)Can the RTD2660H be reprogrammed to split the image?

author: ebastler
author_rank: Super Contributor
timestamp: April 25, 2018, 07:46:36 pm
content: Quote from: ccamacho on April 25, 2018, 07:41:40 pmHuh? Don't you want a stereoscopic display? In which case, where would the two (slightly) different video signals come from?

author: ccamacho
author_rank: Newbie
timestamp: April 25, 2018, 07:54:11 pm
content: Not really,I need exactly the same image twice, this is for using two 12mm FL lenses and to be able to focus the screens at this small distance.I want this for FPV not for VR.Maybe this control board can power two screens like this ?http://uk.farnell.com/densitron/dd-160128fc-1a/display-oled-rgb-160x128/dp/1498857?Ntt=1498857&COM=BeagleBoardOr maybe two screens like this one:http://www.newhavendisplay.com/nhd169160128ugc3-p-5603.html

author: ebastler
author_rank: Super Contributor
timestamp: April 25, 2018, 08:30:56 pm
content: Could you simply connect all inputs of the two displays electrically in parallel? There aren't any (required) signals coming back from the display, I believe? (But have not checked that.)

author: ccamacho
author_rank: Newbie
timestamp: April 26, 2018, 02:07:34 pm
content: Yeah, but these displays need to be 1.8" so the quality and in general the way of putting the signal will be tricky, right?I was lurking in aliexpress and I found this:https://es.aliexpress.com/item/3-69-pulgadas-IPS-pantalla-TFT-MCU-RGB-interfaz-mipi-16-millones-de-colores-480-800/32835680632.htmlDo you think this control board is splitting the signal?This will solve my problem.Looks like it is a stm32 MCU

author: ebastler
author_rank: Super Contributor
timestamp: April 26, 2018, 02:37:51 pm
content: Quote from: ccamacho on April 26, 2018, 02:07:34 pmI don't think there is any signal splitting in the device you show. That one is just showing two copies of the image on thesamescreen, right? So the device will need toduplicate the patternin each scan line (repeat it twice in the output line). But it drives only one LCD, with one set of control signals. If you need to use two separate small screens, this device would not work, I think.But if you can find a single, small wide screen LCD which you could use to display two copies side by side, this could be a solution. But come to think of it: How would this different from the simple VR glass frames which use a mobile phone for display?An alternative thought: If you don't want a stereoscopic view, have you considered using just a single display and mirrors/prisms to show it to both eyes? Probably a more bulky solution, though.

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 26, 2018, 04:40:55 pm
content: Quote from: ccamacho on April 25, 2018, 07:54:11 pm160 x 128 resolution for hdmi? you are abusing yourself... i also thought of building my own fpv, i bought some stuffs but never got the time to assemble them... just buy one of thesehttps://www.ebay.com.my/itm/Reverse-Rear-view-Parking-Car-Monitor-Camera-ABS-4-3-HD-Video-LCD-TFT-Display/152359418163?hash=item2379543933:g:yH4AAOSwA3dYVN~54x the resolution and a fresnel lens, make some diy hood and done... dont torture yourself too much there are plenty of time to enjoy not to be wasted...

author: ccamacho
author_rank: Newbie
timestamp: April 27, 2018, 03:47:26 pm
content: Hey Mechatrommer!Best answer ever!Thanks a lot to all of you!