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Serial port communication


#1

HI,
I am having some problem during the communication between my pc and emx module via serial port. Can anyone help me with the steps that I should follow to connect the module’s serial port to that of my pc?
Thanx in advance.


#2

Do you have a serial to USB connector, or are you trying to connect directly to a DB9 connector on your PC? Please tell us a bit more information about your setup and we’ll see how we can assist!


#3

Thanx for your reply Brett.
I am using a DB9 connector on my PC and using USB as the power source in the module.


#4

ok, a PC port using a DB9 means you still need an RS232 level shifter. As far as I know, the Cobra doesn’t come with a level shifter onboard (max232 or similar). And most modern PCs are unlikely to work on a TTL level signal wired directly into the DB9.

Two options I can see.

First, use a RS232 level shifter connected to the Cobra/EMX UART pins, to get you a DB9-ready signal. Then cable the outputs of the RS232 shifter to the appropriate pins on a DB9 plug.

Second, avoid that and get a USB to TTL serial module, and connect the UART outputs to the USB serial module’s inputs, and ignore the DB9


#5

Third option came to mind. Use the USB cable you’re already using for power and deployment and debug to include a serial stream. See USBC_CDC in the GHI libraries for information about this. http://www.ghielectronics.com/downloads/NETMF/Library%20Documentation/html/93fcfa03-228b-cbe4-e8a5-9a7a8f36cdf0.htm


#6

Thanx Brett…