RepPanel - A DIY alternative to the PanelDue with WiFi support

seeul8er

@pd Sorry for the late reply! Can you share the link to your display, because there are multiple very similar versions of it and I already had a user that bought the wrong one I clarified it inside the GitHub project page. Can you also share the wiring and a picture of what you can see on screen?
It is not necessary to connect the Duet. The app should start anyways.

@pandaym Hi, the ESP32 is not an issue since it is generally available. I ordered the display directly from china. Since it was below 22€ it is tax free and shipping was OK-fast. There may be other ili9488 displays with SPI (+ supported touch controller) and the same resolution that work and that you can get within the EU. However, I have not tested any of them.

PCR

Dear @seeul8er ,

would you be intrested in a PCB. I will order some PCBs for other projects in China. If you want i could design one!

Best
Peter

seeul8er

@PCR I already thought about it but wanted to keep it as simple as possbile for others to follow for now. Non the less a custom PBC would be awesome!
And if you are willing to give it a try why not.
With that we would get a couple of options to choose from. We could dump the pin headers of the TFT module and use an FCC cable. The DevKit would also not be necessary since the ESP module could be soldered directly to the PCB. Or keep the devkit and and solder it to the PCB since it offers USB power and serial for a low price.
The software does only support SPI connections so a 8bit parallel interface is currently not possible.

@seeul8er said in RepPanel - A DIY alternative to the PanelDue with WiFi support:

the ESP module could be soldered directly to the PCB

how much flash do you need? (ESP8285 is cheaper and smaller but only 1MB)

seeul8er

@bearer Hardware-wise the ESP8285 is not enough (especially RAM - kind of maxed out on the ESP32). The image needs 1.4 MB at the moment. The software only supports the ESP32.

pandaym

I really like your solution, and decided to try and grab a few pieces for it, as I was already ordering a lot of other stuff off Mouser.com
Since stuff like this is COMPLETELY new to me, could you maybe take a look at these parts I grabbed and see if you think it will work?

ESP32:
https://www.mouser.dk/ProductDetail/Espressif-Systems/ESP32-DevKitC-32D?qs=%2Fha2pyFadugghcwsr%252BfCfoiPKVRrwUbD0eThxd%2FUYFY7U8Wh9XQ4LHYEl5esmHGZ

Screen:
https://www.mouser.dk/ProductDetail/Seeed-Studio/308010014?qs=%2Fha2pyFadujFrWe34c%2Fp962d7Tsl7GBwUGpbcqXmB9KgWxdyEeTeaQ%3D%3D

I have no idea where to begin, but I will figure that out I would just like to know if I overlooked something in the specs for the stuff I needed to find. I just went for ESP32 devkit and from the details of the screen, I saw it was 320x480 and had SPI connection: https://www.seeedstudio.com/3-5-Inch-TFT-Display-for-Raspberry-Pi-Resistive-Touch-Screen-p-2248.html

seeul8er

@pandaym Your hardware looks good to me! The DevBoard is standard so that's perfectly fine. The screen is tricky but it should work. Its touch controller is a XPT2046 which definitely supported by LVGL. I did some searching and my best guess is that the display is from waveshare. Looking at their driver code the chip should be a ILI9486 which is also supported by LVGL and thus by RepPanel

pandaym

@seeul8er said in RepPanel - A DIY alternative to the PanelDue with WiFi support:

@pandaym Your hardware looks good to me! The DevBoard is standard so that's perfectly fine. The screen is tricky but it should work. Its touch controller is a XPT2046 which definitely supported by LVGL. I did some searching and my best guess is that the display is from waveshare. Looking at their driver code the chip should be a ILI9486 which is also supported by LVGL and thus by RepPanel

Thanks a lot, that sounds good! I will dive into it and see if I can figure out how to wire and program it

dragonn

Any 5 inch screens witch could run with LVGL?

seeul8er

@dragonn said in RepPanel - A DIY alternative to the PanelDue with WiFi support:

Any 5 inch screens witch could run with LVGL?

I am afraid not. With 5" screens the resolution usually is not 480x320 anymore. The RepPanel UI is sort of hardcoded for that resolution since it is an embedded system. Besides that, the ESP32 with SPI is not powerful enough to updated higher-resolution screens in time.

pandaym

@pandaym said in RepPanel - A DIY alternative to the PanelDue with WiFi support:

@seeul8er said in RepPanel - A DIY alternative to the PanelDue with WiFi support:

@pandaym Your hardware looks good to me! The DevBoard is standard so that's perfectly fine. The screen is tricky but it should work. Its touch controller is a XPT2046 which definitely supported by LVGL. I did some searching and my best guess is that the display is from waveshare. Looking at their driver code the chip should be a ILI9486 which is also supported by LVGL and thus by RepPanel

Thanks a lot, that sounds good! I will dive into it and see if I can figure out how to wire and program it

@seeul8er any chance I could get some help finding the right way to wire it? I have started, but I got stuck trying to figure out the naming and what was what.

So I got:
ESP > LCD:
3.3V > Pin 1
GND > Pin 6
GPIO 13 > Pin 19 (MOSI - Data line to TFT)
GPIO 14 > Pin 23 (SCL - SPI CLK for TFT)
GPIO 15 > ?!?!? (Slave Select - SPI)
GPIO 22 > ?!?!? (SCL - I2C - touch)
GPIO 21 > ?!?!? (SDA - I2C - touch)
GPIO 4 > Pin 22 (Reset - TFT related)
GPIO 2 > ?!?!? (Data - TFT related)
GPIO 27 > ?!?!? (Backlight - Turn on/off TFT backlight)
And lastly I got GPIO 17 and 16 that will go to the Duet

Mind helping me figure out where the last ones go?

seeul8er

@pandaym

Your touch screen is connected via a second SPI. Mine is I²C. The second SPI and all other pins will be a config thing during compilation (menuconfig settings) The default for LVGL should be the following HSPI for TFT and VSPI for the touch controller - I think you can choose the "RPi MPI3501" config during the build. The pins can be selected/changed but this should work:

GPIO 15 -> 24 (Slave/Chip select for TFT)
GPIO 23 -> 19 MOSI Touch - (but should not be needed?!)
GPIO 19 -> 21 MISO Touch
GPIO 18 -> 23 CLK Touch (same clk for touch and tft)
GPIO 5 -> 26 Chip select Touch
GPIO 25 -> 11 Interrupt Touch
GPIO 2 -> 18

Looks like the backlight is on automatically

pandaym

@seeul8er said in RepPanel - A DIY alternative to the PanelDue with WiFi support:

Your touch screen is connected via a second SPI. Mine is I²C. The second SPI and all other pins will be a config thing during compilation (menuconfig settings) The default for LVGL should be the following HSPI for TFT and VSPI for the touch controller - I think you can choose the "RPi MPI3501" config during the build. The pins can be selected/changed but this should work:
GPIO 15 -> 24 (Slave/Chip select for TFT)
GPIO 23 -> 19 MOSI Touch - (but should not be needed?!)
GPIO 19 -> 21 MISO Touch
GPIO 18 -> 23 CLK Touch (same clk for touch and tft)
GPIO 5 -> 24 Chip select Touch
GPIO 25 -> 11 Interrupt Touch
GPIO 2 -> 18
Looks like the backlight is on automatically

Thanks a lot for the help. I apologize, but I am a complete newbie in all of this stuff, so it is a bit much to chew

Wonder if I understand it correctly. So I still use the pins for 3.3v, gnd and reset like I set them, and add the ones you mentioned? This should make the full wiring this:

ESP > LCD:
3.3V -> Pin 1
GND -> Pin 6
GPIO 4 -> Pin 22 (Reset - TFT related)
GPIO 15 -> 24 (Slave/Chip select for TFT)
GPIO 23 -> 19 MOSI Touch - (but should not be needed?!)
GPIO 19 -> 21 MISO Touch
GPIO 18 -> 23 CLK Touch (same clk for touch and tft)
GPIO 5 -> 24 Chip select Touch
GPIO 25 -> 11 Interrupt Touch
GPIO 2 -> 18

And ESP > Duet 3:
GPIO 16 -> TX PanelDue port
GPIO 17 -> RX PanelDue port

Does this mean I have to bridge it so that both GPIO 15 and GPIO 5 go to the 24 pin on the screen?

seeul8er

@pandaym Sorry my bad. Chip select for the touch must be GPIO 5 -> 26. I corrected it.

Yes. Looks good! All in all its just about knowing SPI wiring in general and then matching the inputs & outputs. The software/compile process will allow you to change some GPIOs, but with this most stuff should already be configured correctly.

pandaym

@seeul8er said in RepPanel - A DIY alternative to the PanelDue with WiFi support:

@pandaym Sorry my bad. Chip select for the touch must be GPIO 5 -> 26. I corrected it.

Yes. Looks good! All in all its just about knowing SPI wiring in general and then matching the inputs & outputs. The software/compile process will allow you to change some GPIOs, but with this most stuff should already be configured correctly.

Arh, thanks! Really appreciate you helping me out!

I guess my challenge is I don't even know wiring in general, let alone SPI wiring.

So this is how I wired it now:

ESP > LCD:
3.3V -> Pin 1
GND -> Pin 6
GPIO 4 -> Pin 22 (Reset - TFT related)
GPIO 15 -> 24 (Slave/Chip select for TFT)
GPIO 23 -> 19 MOSI Touch - (but should not be needed?!)
GPIO 19 -> 21 MISO Touch
GPIO 18 -> 23 CLK Touch (same clk for touch and tft)
GPIO 5 -> 26 Chip select Touch
GPIO 25 -> 11 Interrupt Touch
GPIO 2 -> 18

Connection to the Duet, as far as I understand, can be done either wirelessly or wired like this, right?
GPIO 16 -> TX PanelDue port (which I assume on a Duet 3 is IO_0_out ?)
GPIO 17 -> RX PanelDue port (which I assume on a Duet 3 is IO_0_in ?)

The controllers you mentioned seems to be right according to this: http://www.lcdwiki.com/3.5inch_RPi_Display , so ILI9486 and XPT2046.

So to get started on the software side I:

Installed ESP-IDF
Cloned the project
Replaced the contents of externals/lv_port_esp32/components/lvgl/lv_conf.h with that of main/lv_conf_back.h
Ran idf.py menuconfig

So for TFT display controller I have it set up like this for starters:

I hope it is correctly assumed that there is nothing pre-defined, so I have to do it like that. For the board pinouts, it looks like ESP32 V4 with 38 pins should be correct for the ESP32-DevKitC-32D ?
Then I just chose ILI9486 and left the rest of the main page as is.

For the pin-out I have this, but I don't know if something is missing or wrong here?

Touch controller I set up like this:

With this assignment:

Last thing is the WiFi connection. I cannot tell where I add my SSID and password for it. Am I overlooking something?

seeul8er

Make sure you checkout the LVGL repo at exactly this commit:

git checkout c1f43bfb090df293059ab52baabbdbdd8df00712

The predefined board pinout does not matter. You can set it to manual/None. Just make sure the pins for TFT and touch are defined exactly the way you plan on wiring them.
You have two separate SPI connections. One for the TFT and one for the touch controller. So the "0" in your display pin assignment are wrong since MOSI must be 13, MISO does not matter I think, DC (Data) must be 2 - just as we said above.
The touch pin config looks good. But you wired GPIO 25 for IRQ (interrupt) - go change it from 27 to 25 then or rewire
Adjust the TFT pixel resolution (480x320).

Yes. I think you got the duet UART config right. Otherwise switch the cables

The SSID & password are set via the RepPanel GUI once compiled and flashed.

pandaym

@seeul8er said in RepPanel - A DIY alternative to the PanelDue with WiFi support:

Make sure you checkout the LVGL repo at exactly this commit:
git checkout c1f43bfb090df293059ab52baabbdbdd8df00712

Once again thank you.

After having sort of found out what commits are etc. I hope I found out the way to check it out at that. Is it correct that after cloning I navigate to RepPanel_ESP32\externals\lv_port_esp32 and run the "git checkout c1f43bfb090df293059ab52baabbdbdd8df00712". This gives me the following message:

HEAD is now at c1f43bf Merge pull request #139 from an-erd/fix_mono_disp

Have I gotten that right?

@seeul8er said in RepPanel - A DIY alternative to the PanelDue with WiFi support:

You have two separate SPI connections. One for the TFT and one for the touch controller. So the "0" in your display pin assignment are wrong since MOSI must be 13, MISO does not matter I think, DC (Data) must be 2 - just as we said above.

Alright, I understand most of that now. I have just rearranged the wiring according to the config to make it easier to see the correlation. It seemed as then I was missing the MOSI for TFT. I have tried to rework it, hopefully this sorts it out:

Full Wiring - ESP -> LCD

Power:
3.3V -> Pin 1
GND -> Pin 6

TFT:
GPIO 13 -> 19 MOSI
GPIO 18 -> 23 Serial Clock (Shared between TFT and Touch)
GPIO 15 -> 24 - Slave select
GPIO 2 -> 18 - Data
GPIO 4 -> Pin 22 - Reset

Touch:
GPIO 19 -> 21 MISO
GPIO 18 -> 23 Serial Clock (Shared between TFT and Touch)
GPIO 5 -> 26 Slave select
GPIO 25 -> 11 IRQ

Other than that I got:
Touch controller:

Display controller:

Am I getting there?

pandaym

I thought I would just give it a try to see if something showed up. So I:

Saved the configuration in the menuconfig
Ran idf.py build
Connected USB to the ESP32 and found that it was on COM9
Ran idf.py -p COM9 flash

Unfortunately, the display never came on. So I wondered if it needed power on other pins and used my multimeter to check. I could see that the two 3.3V pins on the screen are internally connected, so are the two 5V pins and the five ground pins.

So I thought that it probably needs both 5V and 3.3V, so I wired 5V from the ESP32 to pin 2 on the screen.

When I plugged USB back in, the screen lit up, but nothing happened:

seeul8er

@pandaym Your config looks good now. Yes you got the commit thing right. Otherwise you'd get a compile error.
Can you check the debug log please? You can do that by running:

idf.py monitor

The 5V & 3.3V thing is strange. I'll take a look at the data sheet later.

pd

@seeul8er Thanks for your reply. I had in fact bought the LCD but the resistive touch version. I've been waiting for the capacitive one to come so that I can have another try. Would there be much reprogramming needed to use the resistive touch version?