problem using two serial devices at the same time

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

problem using two serial devices at the same time

Jump to solution
650 Views
tschtj
Contributor I

I'm using the TWR-K60F120M with the TWR-SER board using both available serial ports at the same time.  I have the shell running on the OSJTAG port without problem (ttyf) now I'm trying to use the serial port (ttyd) for a custom protocol, but for now, I'm just opening and writing a test string to the port.   The open and write are not returning any errors, but the test strings are not what I'm reading from the TWR-SER connector.  Instead, I'm seeing a duplicate of all the shell output from ttyf.

Any thoughts would be appreciated.  I don't understand why I'm seeing this.

Tom

0 Kudos
1 Solution
450 Views
DavidS
NXP Employee
NXP Employee

Hi Tom,

Not all tower designs (form, fit, functionality) are identical.  Some Towers have independent UARTS going to the OSJTAG(debugger interface) and TWR-SER card.  Other Towers have one UART going to both.

The TWR-K60F120M is one of the latter cases where the UART5/ttyf is going to both the OSJTAG and TWR-SER card.  This has advantage of not having to change MQX code to use one or the other serial interface but has a negative that you only have access to one UART.

Regards,

David

View solution in original post

0 Kudos
1 Reply
451 Views
DavidS
NXP Employee
NXP Employee

Hi Tom,

Not all tower designs (form, fit, functionality) are identical.  Some Towers have independent UARTS going to the OSJTAG(debugger interface) and TWR-SER card.  Other Towers have one UART going to both.

The TWR-K60F120M is one of the latter cases where the UART5/ttyf is going to both the OSJTAG and TWR-SER card.  This has advantage of not having to change MQX code to use one or the other serial interface but has a negative that you only have access to one UART.

Regards,

David

0 Kudos