Posts: 1
Registered: ‎09-28-2017

CP2105-EK board-level loopback

Hello. I have a CP2105-EK and have connected P2 and P3 together using a serial cable with a gender changer. I am trying to find a way to transmit with one port and receive on the other. I have played around with various jumper settings but have so far been unsuccessful. Is this possible to do on the CP2105-EK? Thank you.
Posts: 343
Registered: ‎03-03-2015

Re: CP2105-EK board-level loopback



In order to connect two serial ports together, the TX and RX signals have to be switched.  Normally the cable or adapter that does this is called a "null modem".  This can be separate from the gender of the connectors.


On the EK, you could also disconnect the jumpers that go to the RS232 level shifter (J1 and J6), and connect TX to RX from there.