connection raspberry 3 b+ and witty pi 4

What do you mean "connected directly via the pins" and "connect the two via the male and female wires"? Maybe you can show a picture of it?

In the first image, the WittyPI is connected directly to the raspberry. In this case, the raspberry turns on and the home screen display turns off immediately.

In the second image it is connected to it through the male-female connection wires, to avoid a direct connection. In this case it works and stays on on my home screen.

@ornel It seems your connection via male-female DuPont wires are not completed: the GPIO-4 and TxD pins should also be connected.

After connecting these two wires, I believe it will behave the same way with direct connection.

Have you previously made some configurations to Witty Pi via the software? Some configurations may cause similar problem, for example, setting the power-cut delay to 0, as mentioned here: https://www.uugear.com/forums/technial-support-discussion/wittypi4-no-longer-powering-on-rpi5-nor-fully-accessible-over-i2c/paged/2/#post-1254

Have you ever done configurations on Witty Pi via the software? Yes I have already done configurations on the witty Pi but it only affects the
4. Schedule next shutdown
5. Schedule next startup

In addition I followed your idea, that is to say the delay time increase it

[2] Power cut delay after shutdown [7.0 Seconds]

And yet I still have the same observation.

indeed when I add the GPIO-4 and TxD pins through the male-female DuPont connections in my raspberry - wittyPi link the raspberry does not turn on.

But as soon as I remove them the raspberry turns on.

@ornel I think it worths checking whether your Pi's GPIO-4 is shorted to GND or always output 0V. If it is the case, connecting GPIO-4 equals to press the button and keep holding it, which will force Witty Pi to cut the power.

I connected one probe of the multimeter to GPIO-4 (pin 7) and the other to GND (pin 14).
When the system is off I get 0V and When the system is on I get 3.26V
So I tried this script (the script in capture) and I actually get variations (1 or 0) at the GPIO-4 pin.

I can conclude that between the GPIO-4 pin and the GND, I have no short circuit.

@ornel I just realized that you also need to connect GPIO-17, which is used to send out the SYS_UP signal.

On page 44 in the user manual, you can find all pins that need to be connected (highlighted with green and blue) besides the power pins.

Maybe also worth checking the state of TxD pin. It should go to about 3.3V shortly after Raspberry Pi is powered.

the raspberry finally turned on with the witty pi but I find it strange! because:

when I type the command:
sudo i2cdetect -y 1

*it does not detect the x08 bus of the wittipy; I transferred it to the x35 bus; the wittipy is not detected with this command

* this time it refuses to detect my weather sensor; the x76 or x77 buses do not identify themselves; I tried it without wittypi through the raspberry; I get nothing more

@ornel what do you mean "transferred it to the x35 bus" and what are "x76 or x77 buses"?

Depending on the weather sensor I have, I have the x76 or x77 address displayed when I type the command: sudo i2cdetect -y 1

The wittyPi being connected to the raspberry normally the x08 address should be displayed with the command: sudo i2cdetect -y 1

In photo 1, I expect this result but I have rather the result 2

The image below, may be more useful for you to understand my question

my wittypi is well connected but I do not detect it

Hello, I would like to contact you again so that you can help me.

@ornel the output of your "sudo i2cdetect -y 1" is incorrect: each printed address represents an I2C device, and you don't have that many I2C devices connected to your Pi, do you?

How did you change your Witty Pi 4's I2C address from 0x08 to 0x35? The recommanded way is to set the new address to I2C register #16, and modification of firmware is not needed.