Perhaps the Sunton displays are what you are looking for? Maker Fabs example
I am also looking in the market for 480x800 display, though larger size (5 or 7 inches), that works with a ESP32-S3. However since in my project I also require the ESP32 to read data and perform control, most of the commercial boards are useless since they lack a lot of pins.
So one recommendation I would give, if you build this board, is to add some pin headers for the available pins
As for my research on a display that works with the ESP32, so far I set my eyes on the popular 7 inch display by “buydisplay”. Hopefully I can have the ESP32-S3 drive the screen with LVGL, while still having computing power and pins for other tasks.
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woops I didn’t read completely and inferred stuff. The design is excellent and I would only hope you could make a similar design for the larger 5" and 7" 480x800 displays
could easily be adapted to a different display. if the pin out of the ribbon is the same it would simply be a matter of changing the display to a different one. The display is connected to the board using one of those ZIFF connectors so not a permanent connection.
If the pin out is different it wouldn’t be that hard to change the board design
And here it is. updated for that display you linked to. I changed all of the tracers to go where they need to. There is no access to the font chip or the SD card as that would eat up pins. with the S3 having up to 16mb of flash there is no real reason for the SD card or the font chip use.
This is set up for use with a cap touch screen not a resistive.
Awesome! So if I am getting it correctly, this is a module that would fit the display PCB modules (the ones that already have the screen driver + touch driver).
Any plans for in the future having the ESP32, driver (e.g SSD1963) and touch screen driver (e.g. FT5206) all in one module? This would be very cool since then thinkerers could build their own versions of the S3 screens sold by Sunton by using the devkit PCB (with appropiate drivers) + a bare-bones display from BuyDisplay + whatever extra components they’d like to add.
This board I am going to make is specific to a display. The reason being is the manufacturers of the displays don’t use the same pin outs. The hard thing with a 7" screen is locating one that supports the i8080 interface. at 7" you start seeing mostly RGB and MIPI display connections. The ESP32 doesn’t support the MIPI connection natively. There is a bridge that can be used which converts i8080 to MIPI. RGB just uses a whole lot of pins plain and simple. 8 pins for R, G and B and then additional pins for VSYNC and HSYNC. and some others as well. If using an RGB display that supports RGB565 or 16bit color you can shrink the number of pins being used down by 8 pins but it is still a lot of pins that end up getting used.
I have thought about building a dual ESP32 dev board so one ESP would be for IO and the second would be for the display so an RGB display could be used but LVGL doesn’t support 24 bit color out of the box and it would have be set to 32 bit color and the alpha byte would have to be stripped off in the flush function.
I think the ESP32 would be able to update something like a 7" with a resolution of 1024 x 768 so long as it wasn’t doing anything other than the display. There would have to be some alterations made to utilize both cores and some kind of a mechanism to allow the 2 MCUs to communicate with each other.
Running 2 ESP32’s would be cheaper than adding an IC to expand the number of digital IOs and another IC to expand the analog IOs and yet another IC to add PWM outputs. I2C would have to be used because SPI would take up too many additional pins. one CS for each of the 3 ICs and the original 3 used for the SPI itself totaling 6 pins needed on top of the 30+ used by the display.
an ESP32-WROOM-1-N8R8 (8mb RAM and 8mb flash) has a retail cost of just under 4.00 USD. a 4 channel 12bit ADC has a retail price of about 4.00 USD. It’s cheaper to go with a second ESP32 because that is just the ADC, not the digital IO and the PWM.
I would say that already with a screen like the ILI9488 3.5 inch (480x320 Pixel) the refresh rate is almost at the limit with an ESP32 wroom 30 Pin.
If I were you I would limit myself to making an STL containing ESP32 and screen, or a PCB with the connection traces between ESP32 and the screen.
Combining 2 ESP32 together seems to me a more complicated thing (and perhaps with the wifi connection you save some connection)
Here you can see a project I made for a table clock with wind signal (code included).
HI
@gabriele_ponte
how do you have the esp32 connected to the display??
I ask this because it could be what you are preceiving asmaxing out the sped of the ESP… also have you changed the way LVGL updates the display or have you left it as is? do you have any other code running on the ESP?
an ST7889 driver IC has a clock of 50mHz for i8080 and you can go to 80mHz for SPI. SPI is able to send 1 bit at a time so you would get a speed of 80Mbit a second. with i8080 you get 50mHz which is 50Mbit but then you multiply that by the number of lanes. so a 16 lane has a speed of 800Mbit, 10 times faster than SPI. That is a hell of a speed increase but at the cost of using a lot of GPIOs on the ESP.
That is theoretical and not real application. SPI is going to be slower as is i8080. The difference in speed should still be about the same…
@pllagunos
The touch driver ic and the display driver ic are actually built into the flexible PCB that comes out of the back/side of the display. So all that has to be done is the routing of the GPIOs from the ESP to the connector for that flexible PCB. The display you posted has a rigid board on the back that has the driver ic for the display and touch and it also has an SD card reader ad well as a font chip. Those additional components are the reason why they used a rigid PCB instead of a flexible one.
You can find the connections I used in the .Zip file (or at the end of the youtube movie) and also the LVGL and TFT_espi configuration I used (to be precise, I used LVGL version 7.11).
The connections use 8 pins of ESP32 or 9 if you want brightness correction via software.
I didn’t try to use larger screens because the 3.5-inch size was enough for me, but I saw that with this size the refresh rate was still decent.
HI
if it’s an 8 wire connection it’s gotta be 4 wire SPI.
the speed in which the display is refreching is not a limitation of the ESP32 or LVGL but instead is a limit of the display. If you have a grip of unused GPIO pins on the ESP32 then you could run a display that can do an 8 lane i8080 connection. You would need 8 pins for the data lines, 4 pins for the control lines, a pin for hardware reset (optional), another for the backlight (optional), the 2 pins for the data from the touch panel, hardware reset for the touch panel (optional) and an interrupt for the touch panel (optional)
If you don’t use any of the optional pins you would need a total of 14 pins, 6 more then you are currently using. 8 lane I8080 would be 5 times faster than SPI. still a respectable boost in speed. On the ESP32-S3 there is a lot of pins and I would be surprised if you are using them all. You can connect a 16 lane i8080 display and still have 3-4 pins left for use on other things.
I wanted to do a 16 lane connection to a display that has a really high resolution of 800 x 640 for a 4" display with 24bit color. It would look really amazing. Thing is I need more than 3-4 GPIOs left over. I need to have 10 additional pins most of them being analog.
Using 2 ESP32’s shouldn’t be too difficult to do. I can use I2C to send data from one that is handling everything other than the display. assign id’s to the various widgets in the display so the data that is sent would be the id and then the data I want displayed. the other ESP I would run LVGL on to handle the display. modify do away with the timer related bits in LVGL for refreshing the display and reading the touch interface. The only thing that would be getting done is reading the touch, reading the I2C for data to update the values in widgets and updating the display.
I have not published the code anywhere. The simple version of what I did is delete the timer for the display refresh and I call the refresh callback periodically in my code. I handle the animations myself and I also monkey patched some of the code for how the touch screen is handled so it gets priority.
almost there. dual ESP32-S3’s. One for sensors and the other connected to the display using 16 lanes. I2C used to connect the 2 together. If you really think about it how much data would get sent between the 2. Not all that much really. SPI can also be used to communicate between the 2 and also WiFi
I would definitely be interested in this! Would be great to have access to design files of the PCB, in case someone want’s to add more components to the PCB. For example terminals/connectors for sensors, amplifiers/optocouplers/whatever to have compatibility with things like thermocouples or just pins to connect common modules.
I made a PCB that has a ESP32 driving a small 2.8" TFT display on the front and has all the connections for sensors in the back side of the PCB.
I actually am working on it now. I changed up the design. it now has a 4 layer PCB. 2 ground planes a power plane and a signal plane. the layers are as follows.
top: power
second: ground
third: signal
bottom: ground
I stuck the signal layer between the ground planes to eliminate EMI getting to the signal wires. This will reduce noise on the signal lines.
Every available pin is broken out to a pin header. the ESPs are connected together via a dedicated I2C. That I2C is also broken out. The touch has it’s own I2C. display connection is for a 16 lane i8080 interface to one of the ESP32’s.
Whats cool about how the board is designed is you see next to no traces on the board. I am also using blind vias and all of the vias for the ESP’s are under the ESP so you won’t see those either. The overall board measurements are 1.9" (48mm) x 2.2" (56mm) x 0.35" (9mm). That’s without the display. The display adds 2mm for an overall thickness of just a tad under 7/16" (11mm) thick. The board only covers 1/2 of the back of the display. This is important because it leaves room for an add on board so the thickness can be maintained depending on the design on the add on board. There is 2mm of space between the board and the display so there is room to have components on both sides of an add on board.
the display I am going to use has a crazy high 54,852 pixels per square inch. I think the ESP is not going to have an issue driving this display. It’s not going to be able to do video but it should have pretty decent transitions and animations.
One other thing is the ESP’s I plan on using are going to have 8mb of flash and 8mb octal spiram on each of them.
I haven’t gotten any fabricated yet. Been really busy. I need to go over the PCB design and make sure everything is how it should be. Last thing I was doing on this was looking for a way to make a connection between 2 PCBs that would be a really solid connection. something that was really small too.
