Is it possible to hook up sim800l to nucleo and pc at the same time?(schematics included)

[Apakp.1]

hi everyone , i want to set up my circuit in such a way that as soon as i turn on my board it starts sending AT commands to sim800l to put it on GSM mode and do some stuff ,is it possible to put my pc in the middle like in the picture?

[Apakp.1]

i'm sorry but i did not have enough space to ask my question completely , so i will have to add a comment to do so :( so what confuses me is that USART2 is connected to the USB which is connected to my PC and i can send and receive messages between sim800l and my pc using virtual com but can i use USART2 to achieve the system that i have so masterfully drawn in paint? :p

[Tesla DeLorean]

Ok, you ran out of space because you tried to put the entire question in the title rather than the body of the question.

But basically yes, you can listen to the output of a serial comm line by connecting it to the receive pin of a USB-to-CMOS Serial type dongle (SiLabs, FTDI, whatever)

From the modem side, be sure TX is the OUTPUT of the signal

[Apakp.1]

thanks for your quick response it was my first ever question on these forums so i made a mistake, i have edited my topic :D so after searching the internet i came up with something like this:

https://www.adafruit.com/product/954

but using this i can only conect sim800l to my laptop , what about the mcu?(i am writing a firmware and i was thinking that being able to see the responses from sim800l to the MCU could help me debug rather than trying to toggle the only user LED available on my board to somehow indicate if everything was successful or not )

[Tesla DeLorean]

You can connect primarily to the STM32, and then simply fork the pin you want to monitor into the RX pin, and common the ground.

On the NUCLEO-F446RE side you could use the VCP (Virtual Serial) port and have that echo back data you see/process on the primary UART you're using to connect with the SIM800L (via whatever level converters it might need to operate at the 3.3V of the NUCLEO). A NUCLEO-144 board might be more accommodative of multiple USART, at least at the Arduino shield interface.

https://www.st.com/en/evaluation-tools/nucleo-f446re.html

The STM32 also provides for a SWV (Serial Wire Viewer) interface using the SWO pin of the chip, and the support for that in the ST-LINK/V2 and your debugger.