Problem with screen on/off

[FabienArr]

Hello,

I don't understand, i have problem with my screen which sometimes is on the night is off. But the morning he doesn't restart but i have the information on the webpage of my inverters.

I have this wiring : https://waldy-smarthome.de/opendtu/images/OpenDTU-Wiring-CMT2300A-Display.png

My profile is :

The config screen :

I need to restart or change the profile file and restart for the screen to display again, it's very curious.

Thanks for your help.

[schneeer]

Hello,

Is the correct display type set?
Type 2 is for SSD1306.
Which display do you have?

The display shouldn't turn off at all because you have set power saving to off, really strange.

Type 1= CD8544
Type 2 = SSD1306
Type 3 = SH1106
Type 4 = SSD1309
Type 5 = T7567_GM12864I_59N

Have you installed everything on a circuit board suitable for openDTU? Or are you testing on a breadboard first? I had problems with my nrf24 when using the breadboard.

[FabienArr]

Hello,

Thanks for your replies.
Yes i have the CMT with a board and 8 pin header like that :

For the voltage, a picture is better :

But for the 5V, there is only 2 pin for power component, the 3,3V is for the CMT module and the second of 5 v is for screen no ?

For the capacitor, it's just that i have only 1uf in stock. But the radio module works perfectly.

[schneeer]

I have to admit that all openDTU instructions are the same as your wiring.
The displays on my DTUs are also connected this way.
5V for the display, 3.3V for everything else.
That works most of the time.
Theoretically, a level converter had to be connected between the ESP32 and the display.
The simplest ones look like this, so you can adjust 4 signals:

I don't know if that solves your problem either.
Pins 21 and 22 on the ESP could also be defective.
You could try 2 others.
Then of course the pin_mapping.json needs to be corrected and loaded onto the ESP.
The display may also have a defect.

As I said, the ESP32 can only handle 3.3V.
Therefore the data lines SCL and SDA are only at around 3.3V

The 5V pin doesn't change that. This is where the voltage of the USB port comes here out.
There is also a voltage IC on the dev board for the 3,3V.

Unfortunately you don't have any additional/duplicate hardware to try.

These are the boards I have there:

But they are only useful if you have a 38-pin ESP32 Dev board.
It doesn't matter which receiver you solder in where. The pin mapping must be correct.

[schneeer]

Just for information:
I know that some LCDs have problems with the Arduino (5V) or the ESP (3.3).
These are pullup/pulldown (?) resistors on the display board, which have to be resoldered.
Then it works on the other platform.

[FabienArr]

Hi,

I have a 32-pin ESP32 so the board will not be compatible.
I tried to put on D13 and D12 without success. Do you think i need to use another LCD ? or more an ESP ?
I found a french article on LCD : 0x7A(8bit) = 0x3C (7bit), the cms resistor is on the 0x7A so i need to use the 0x3C to communicate with it
https://passionelectronique.fr/ecran-oled-i2c-arduino/
Where i can find this information in openDTU ?
I think i will buy a screen and esp on ali.... for open dtu

Regards

[schneeer]

Great website.
The topic of addresses is well explained here.

I think 0x7A / 0x3C is a standard address and does not need to be specified.
In any case, there is no setting for this in openDTU.
There's nothing in the program code either.
The u8g2 library used apparently knows the address.
I don't know why it works like that in OPenDTU.
If you are interested, you can find out at the linked address.(??)

I also often order from AliExpress.
This is the same stuff you get in all other shops. You just have to know what you want and what you will get in the end.
The item descriptions are often bad and often poorly translated.

The display is the cheapest of all the components, I would replace that first.

[FabienArr]

Hello,

I think i will buy the 2 components.
I found a PCB card, do you think it's better than cable wiring ?

Regards

[schneeer]

Hi,

a circuit board helped me with my problem with the nrf24.
Difficult to answer.
You seem to be the only one with the display error.
In any case, the two of us are the only ones dealing with this problem.

If you've tested a replacement display, we'll know more.

[FabienArr]

Hi,

I place the order. I will come back in 2 weeks.

Regards

[schneeer]

Ok

[FabienArr]

Hi,

The screen is dead, the new one works perfectly.

Sorry and thanks.

[schneeer]

Hello,
well, very nice.

You don't have to apologize. Even if the troubleshooting didn't help in some cases, we worked with the technology and learned something along the way.