I have a WiFi module that only needs two wires connection to work. These are RX and TX pins connected to Arduino or the CR-10S printer board but I don't know if there is any physical or software UARTs TX and RX pins. My goal is to add a Wifi support to the CR-10S printer. Since this is not Arduino and the pins are not labeled, it's hard to tell which TX and RX pins are not being used.
In the image of my motherboard below, any port or pin with line pointing to is considered as being used by the printing software so I can't used them.
There are still ports or pins that are not used. Can any one tell if there is a TX and RX pin that is not being used from the image above? I need them to communicate with the printer wirelessly.