I would like to use this module https://www.amazon.it/gp/product/B078Q3D5MV/ref=ask_ql_qh_dp_hza
to turn on a light after send to ESP01 a special command by wifi.
Now I want to link a PIR motion sensor.
The esp01 is totally connected to relè module, so I dont know if I can use the other pins on the breadboard (rx and tx) to detect input signal from PIR motion sensor (like PIR HC-SR501).
Thanks in advance
Your link does not work. Your answer is probably not enough information for a definite yes or no.
preacher78:
I would like to use this module https://www.amazon.it/gp/product/B078Q3D5MV to turn on a light after send to ESP01 a special command by wifi.
Now I want to link a PIR motion sensor.
The esp01 is totally connected to relè module, so I don't know if I can use the other pins on the breadboard (rx and tx) to detect input signal from PIR motion sensor (like PIR HC-SR501).
Link corrected - that garble happens with some systems, not seen it recently but it has been a problem before.
OK, it seems you have a HW-655 module which has a secondary processor on it which "talks" to the ESP-10 via the Tx and Rx pins which are also brought out to the side of the board. It responds to its own "AO" commands! Seems an unnecessary addition, the other relay board does not use it.
Expand!
There is also noted a potential problem with "clone" boards not made by the original manufacturer on which that secondary processor is not programmed, making it unusable!
In any case, you cannot simply use Tx and Rx to connect other devices but with care (they must be pulled high at boot), you can use the otherwise unconnected GPIO0 and GPIO2 pins on the ESP-01.
How you program for that is up to you, given that you already have the source code for the ESP-01 on that module.