Why are there so few OLED displays in the 320x480 area? - Page 1
Forum section: electronics / general

author: peter-h
author_rank: Super Contributor
timestamp: August 21, 2025, 09:14:25 pm
content: Most I can see are little ones.There is an absolutely vast range of backlit LCD ones e.g.https://www.buydisplay.com/serial-spi-3-5-inch-tft-lcd-module-in-320x480-optl-touchscreen-ili9488but a lot of searching has not found OLED versions.I know there is the issue of their short life so maybe it is accepted there isn't much of a market for a display which will last only a few years?

author: thm_w
author_rank: Super Contributor
timestamp: August 21, 2025, 10:50:32 pm
content: You can find them, they are just expensive, the market is not that large due to cost.https://www.youritech.com/products/3-26-inch-854-x-480-medical-industrial-digital-camera-control-amoled-display-industrial-screen.htmlhttps://www.alibaba.com/product-detail/Original-New-3-2-Inch-320x480_1600136867636.html

author: peter-h
author_rank: Super Contributor
timestamp: August 22, 2025, 06:15:25 am
content: That was well found - thanks!They are maybe 3x the cost but that's OK for most embedded industrial applications.I've asked for data sheets.Edit: That youritech display is discontinued. The guy offered me the backlit one on the buydisplay link for $7

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 22, 2025, 02:39:35 pm
content: In terms of cost and availability for the larger or high-res OLED panels, your best bet is to go for panels used for portable devices, like smartphones. But then interfacing will usually require MIPI or something similar, not a simple SPI or parallel interface with onboard controller, so that's a whole different territory, not necessarily great for MCUs.Note that beyond price and availability, OLED panels have limited lifetime, limited brightness and limited operating temperature range, so they may not be ideal for industrial applications.The contrast you get with OLED is unbeatable, but otherwise, may not be that good a "deal", so the big plus is mostly for the looks, and I don't know if looks matter at that level for typical industrial applications, but you're of course only judge of what you want to design.

author: peter-h
author_rank: Super Contributor
timestamp: August 26, 2025, 10:24:00 am
content: Yes - MIPIThey recommend this onehttps://www.youritech.com/products/3-17-inch-oled-display-360x640-rgb-spi-amoled-display-for-industrial.htmlbut MIPI is completely out of the question. For a start you need tons of external RAM, and that usually means using the biggest available package.

author: asmi
author_rank: Super Contributor
timestamp: September 02, 2025, 06:35:35 pm
content: Quote from: SiliconWizard on August 22, 2025, 02:39:35 pmI'd say that MIPI is actually easier on a physical side, as it's just a few differential pairs, and it's a very low power interface by design (due to very small voltage swing) - unlike say LVDS or parallel RGB. Many higher-end MCUs support it natively, but you will likely need to add some external RAM of some kind for framebuffer(s).Quote from: SiliconWizard on August 22, 2025, 02:39:35 pmOLED is useful in applications when you have to work in very low light conditions - like an infotainment or a dash display in a car, which is why they are getting more and more popular in automotive (absence of backlight means less chance of blinding driver during the night). OLED panel is also thinner, which may also be important. The only real downside of it (along with the price) is a burn-in issue, but with some clever UI design it can be somewhat alleviated.

author: behoo
author_rank: Newbie
timestamp: September 03, 2025, 03:40:58 am
content: Quote from: SiliconWizard on August 22, 2025, 02:39:35 pmThe "O" in OLED is Organic. Which means degrading more easily. Especially for Blue sub-pixel. Blue provides the most light power. It degrades faster.

author: paulca
author_rank: Super Contributor
timestamp: September 03, 2025, 11:31:49 am
content: There should be "old" phone screens available, probably a different tech, but they should come in many larger sizes.The TFT screens all seem to originate in the Nokia N95 era before iPhone et. al. took off. Surely there should be excess/surplus of the older style phone screens from the 2010s coming onto the market for cheap?The other aspect is "Why bother?". If you have noticed nearly everything with a UI these days just uses an embedded SBC and uses an "actual screen" with HDMI etc. Linux or even Windows OS. If your product budget doesn't stretch to that, a BT module and write an app. I think MCU "GUIs" beyond basic dishwasher and microwave displays are a thing of the past.Developing good, accessible, internationalised, secure, UIs is not productive on MCU platforms.

author: peter-h
author_rank: Super Contributor
timestamp: September 03, 2025, 11:54:21 am
content: There is a fantastic choice of backlit LCDs, very cheap, like thishttps://www.buydisplay.com/catalog/product/view/id/2062/s/1-54-inch-ips-tft-lcd-display-240x240-st7789-connector-type-fpc/They are fine for embedded work, with SPI, 8/16/24 bit parallel interfaces. They look really great and much better than the ones we used in the 1980s, and in the early phones. For videos, a bit tough but the 24 bit parallel would do it. But you rarely need video in this application sphere. On a 240x240, 20MHz SPI, you could do an MP3 player with the usual "spectrum analyser" displayThe perpetual challenge is if you want to make the product for many years. The displays will change, but you will probably always be able to get 320x480 etc.

author: Psi
author_rank: Super Contributor
timestamp: September 03, 2025, 12:17:14 pm
content: Make sure you also check the physical aspect ratio when looking for any sort of display, don't just go by resolution.You will sometimes be caught out when you encounter one with pixels that are not square.Even if you don't really care much about the exact aspect ratio, if you get one with non-square pixels it will make things annoying when you go to draw stuff.If you draw a circle it will look like an ellipse and you will have to write a conversion layer to correct it.They aren't all that common, but that makes it worse because you will get away when not checking most of the time, but sooner or later...