7 inch display for lichee nano - Page 1
Forum section: electronics / projects

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 30, 2021, 06:51:46 am
content: I'm looking for a 7 inch lcd for a lichee nano to do development for the scope but find it hard to obtain specifications of displays offered on aliexpress.I asked the seller of this one (https://nl.aliexpress.com/item/32691414835.html) for a datasheet, but they don't have itSearching on google does not render much info either.I think it is a 50pin and might be the same as what is in the FNIRSI-1013D.Anyone any suggestions or a pointer to a cheap (Less than 20 euro) 40pin 7 inch 800x480 lcd compatible with the lichee nano. Preferably on aliexpress.See attached schematic of the lichee nano I found on the net

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 30, 2021, 06:12:48 pm
content: Looking at the docs for the Lichee nano (most of which is in Chinese), it seems to support 800x480 RGB LCD panels, among others, with optional resistive touchscreen.Adafruit happens to have exactly that:https://www.adafruit.com/product/2353They also have a version with a resistive touchscreen that the Lichee Nano seems to support as well:https://www.adafruit.com/product/2354(but this one is out of stock.)It does have the 5" version with touchscreen in stock though:https://www.adafruit.com/product/1596Judging from the datasheets and the schematic you posted, the pinout of all those panels seems compatible. The datasheets are available on the above pages, so if you really want to find them on Aliexpress you can specifically look for the references. Although I wouldn't find this particularly fair for Adafruit, as I found those panels thanks to them.

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 30, 2021, 07:39:08 pm
content: Thanks for pointing this one out to me. I was able to find same kind of information on vendor sites like Farnell and RS components with similar prices. Since it is hobby and does not generate income I have to try to buy cheap. The problem lies in trying to match the found information with what is offered on aliexpress.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 30, 2021, 09:07:34 pm
content: I think it's a lost cause. The only panels that looked similar (but without datasheets, so you can never know) were on Alibaba. From $25 to $50 a piece. Do not expect anything cheaper than that. And sure, one at $25 would be half the price of Adafruit's (or Farnell's) ones, but without any documentation, is it worth trying to save $25, at best, while possibly getting something that won't work?Do no expect this kind of panels (7", 800x480, RGB interface) to be particularly cheap anyway. Those are relatively uncommon these days, and have been largely replaced with ones with either MIPI or eDP (for larger ones) interfaces. Even the resolution is not that common anymore.

author: Algoma
author_rank: Frequent Contributor
timestamp: March 30, 2021, 09:15:40 pm
content: There is a model number on the pictures in this article:40pin RGB LCDwould be the search term.https://unframework.com/2020/05/27/setting-up-embedded-linux-on-lichee-pi-nano/https://www.aliexpress.com/item/32656532585.html4.3 inch seem reasonable price, the 7 inch is quite a bit more.

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 31, 2021, 06:14:30 am
content: Thanks for the info. I know it is tricky to buy on aliexpress. And prices for LCD screens aren't that much better than from regular suppliers. I will take a gamble on this one:https://nl.aliexpress.com/item/32691414835.html. At 10 euro free shipping the loss is not that big if it does not work.Probably have to make a converter board with some power supply stuff on it to get it to work. Chances are it is compatible with the display in the FNIRSI-1013D (The lichee nano project is intended as aid in developing new software for the FNIRSI) for which I reversed engineerded the schematic.

author: Algoma
author_rank: Frequent Contributor
timestamp: March 31, 2021, 06:19:17 am
content: The lichee nano firmware (F1C200s) is also the foundation for the application processor in the new Hantek DSO2D10 scopes.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: March 31, 2021, 08:22:58 am
content: Thanks blueskull for sharing, I use Techstar lcd as my main TFT supplier, what other Chinese brands do you recommend?

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: March 31, 2021, 07:49:40 pm
content: QuoteThanks, I did not know them, do you have their official website and the place to buy form them?

author: pcprogrammer
author_rank: Super Contributor
timestamp: April 10, 2021, 07:44:02 am
content: I received the display I bought (https://nl.aliexpress.com/item/32691414835.html?spm=a2g0s.9042311.0.0.27424c4dER5LsR) but it does not work with the FNIRSI-1013D. It shows some white fading and stabelizes in a blue bar on the right side of the display.On the cable there is "7300130906 E231732 NETRON-YF P08 94V-0\1332"Does someone have an lead to the specifications?

author: pcprogrammer
author_rank: Super Contributor
timestamp: April 10, 2021, 09:39:27 am
content: I made a video of what it does and posted it on youtube (https://youtu.be/K5SbKid2z_o)

author: Algoma
author_rank: Frequent Contributor
timestamp: April 17, 2021, 10:06:34 pm
content: The Hantek DSO2D10 was reported to use a TM070RDH13 display connected to their Allwinner F1C200s (Firmware is based on LicheePi Nano) (if this information useful in anyway to track down a likely pinout).

author: pcprogrammer
author_rank: Super Contributor
timestamp: April 25, 2021, 02:08:35 pm
content: Not sure, but for the display I have, it is not the pinout. I need to find the correct settings for the scan frequency. When connected to the FNIRSI-1013D it seems to work, but due to wrong settings of the DEBE in the F1C100s it is not displaying correctly.Once I have re-engineered the scope software I will have a go at changing the settings to see what it does.I also found another display on aliexpress that is the correct one for the scope. Needs additional power to be connected to the lichee nano. Did not try that yet.https://nl.aliexpress.com/item/32693491775.html

author: pcprogrammer
author_rank: Super Contributor
timestamp: December 06, 2024, 03:35:19 pm
content: After many years I revisited the then bought 7 inch display. After searching the net I did find some datasheets for 7 inch 1024 * 600 LCD's with a 50 pin RGB TTL interface. If they match the display I have, I don't know, but at least the pin out seems to be universal and matches with the 800 * 480 LCD's with 50 pin RGB TTL interfaces.I connected the display to my lichee nano setup and started tweaking the settings based on what I found in the datasheets. I managed to get an image, but it flickers to much. Watching the sync and enable signals with a scope showed that the refresh rate was about 23Hz leaving a very big gap between two actual data sets. Tried changing the settings for the vertical back and front porch, but the change in the front porch setting seems to do relatively nothing. (Very high setting reduces the rate to about 18Hz, but setting zero gives the 23Hz)I reconnected the 800 * 480 LCD and loaded the correct settings for that one. This results in a stable picture and a refresh rate of about 117Hz.Unfortunately the documentation of the F1C100s is very poor and does not help much. It does state that it should be capable of doing 1280 * 720 @ 60fps, so way more then the 1024 * 600 @ 23fps I'm getting.Any one out there with a bit more experience with the F1C100s display engine that can shed some light on this?The code I tested with is based on the project with this file for the display controlhttps://github.com/pecostm32/FNIRSI_1013D_Firmware/blob/main/fnirsi_1013d_startup_screen/display_control.cwhere I changed the size settings to 1024 * 600 and the timing registers like shown below.Code://Correct these for the 1024 x 600//Use the default configuration//Horizontal total time and horizontal back porch (1344 clocks per line with 160 clocks back porch)//This depends on the total line time and the back porch//Back porch = (140 - 1);*TCON0_BASIC_TIMING1 = 0x53E008B; //0x41E0044;//Vertical front porch and vertical back porch (12 lines front porch with 23 lines back porch)//This is a bit of a mystery for the front porch setting. Even with 0 there is a gap between the last line displayed and the next sync pulse of many lines (~30ms)//The back porch setting includes the sync pulse lines too??*TCON0_BASIC_TIMING2 = 0x16; // 0x46E0016;//Horizontal sync pulse width (20 clock pulses) and vertical sync pulse width. 0 means 1 line time for the vertical sync//HSPW = (20 - 1) << 16;//VSPW = (3 - 1);*TCON0_BASIC_TIMING3 = 0x130002;

author: pcprogrammer
author_rank: Super Contributor
timestamp: December 06, 2024, 05:50:33 pm
content: Never mind. I found this repositoryhttps://github.com/nminaylov/F1C100s_projects/tree/masterand it showed how to calculate the settings for the vertical frame.The manual is a bit unclear where it states that a setting is vertical front porch in lines, where it actually is the total number of lines (back porch + sync pulse + front porch) times two.Playing with this setting also showed that when it is to small the frame rate is significantly lowered. I still have to tweak the settings to get the position in both directions just right, but I now do have a stable screen of 1024 * 600 @ 72fps.