You just wrote the device's name. Nothing else. This forces your potential helpers to do work that you could have done yourself to make it easier for your potential helpers to help:
providing a link to the documentation of the device.
with a quoogling I found this
it shows which connector to use and which IO-pins are used for serial communication.
by the way: the OpenCM seems to be a 3.3V device while the Uno is a 5V device.
You may have damaged your OPemCM through directly connecting it to 5V
best regards Stefan