Chinese ESP32 LVGL displays

[baffled2023]

Hi

I need a touch display, and lets face it... a lovely display with it all built on board would be great.

I have had a tinker with one of these before...

https://vi.aliexpress.com/item/1005005865107357.html?spm=a2g0o.cart.0.0.6d2138dahpf0cq&mp=1&gatewayAdapt=glo2vnm#nav-review

BUT.... I found them to basically have next to no way of interfacing with them... which kinda makes them pointless.

From the terrible schematic (only partially English), I can see a terminal called Extended IO. But this just appears to be I2C and 5v.
Even then, if you look elsewhere on the drawing (capacitive touch wiring), Pin 21 appears to be held to ground with a 0R resistor (which other people have noted).

The next I/O slot is called Temp and humidity..... yet just appears to be the same I2C terminals.

They have wasted I/O pins with an onboard RGB, SD slot, Photoresistor etc.

Shame... there is literally nothing to connect with.

I suppose you could unsolder the RGB and regain those pins.

In particular, I needed 2x serial outputs. The socket marked Power supply base appears to have an RX/TX in it, but the schematic shows it marked as both TX0/RX0 and TX2/RX2... not sure how that works. Is that basically a repeat of the USB connection? (I suspect so).

I could software serial my 2x required serial outputs, but I basically can't see any viable pins.

I was going to order a capacitive touch version.. so does that free up the pins labelled resistive touch? Who knows!

Anyone had a go with these things?

[UKHeliBob]

Take a look at GitHub - witnessmenow/ESP32-Cheap-Yellow-Display: Building a community around a cheap ESP32 Display with a touch screen

[ZinggJM]

I am quite sure this is also supported by Arduino_GFX. See also Arduino_GFX_dev_device.h.
I think I have the same, but have not yet tested this one.
-jz-

Maybe we could add an SPI connected port extender to the SD card pins? e.g. MCP23S17.

[ZinggJM]

@UKHeliBob, Thank you for that link! Looking forward to play with this display. And maybe even use it.

[baffled2023]

So.... from Bob's link above

https://github.com/witnessmenow/ESP32-Cheap-Yellow-Display/blob/main/PINS.md

This is that screen and there are basically zip pins to connect to, unless you unsolder the RGB and maybe the photo-resistor.
I suppose you could lose the SD card slot, but I didn't really want to get into dismantling it all, plus the SD card slot is very handy for loading graphics.

Shame. For me, that renders the screen pretty useless.

I will continue the search....

[UKHeliBob]

@baffled2023

there are basically zip pins to connect to

There are a number of pins available on the connectors, although not many