Unable to see UART output on hyperterminal

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Unable to see UART output on hyperterminal

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net11
Contributor III

I am using the MCF5234BCC EVB. Codewarrior v7.2  offers two targets for this board - Console Internal and Internal Ram.

 

 I have been trying to see the output of the simple example "Hello world" written in C. The code is the main.c from the default project in Codewarrior. I can see the output fine for the Console Internal Ram target. However when I change the target to Internal Ram, connect a serial cable and try to observe the output on a hyperterminal, I cannot see anything. The hyperterminal just stays blank. 

 

I have connected the COM port though a DB9 serial cable. The comunication settings for the hyperterminal are 

Baud 19200

Data Bits 8 

Parity None

Stop Bits 1

Flow Control None

 

What is going wrong?

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net11
Contributor III

Thanks TomE. I checked the serial port connections and it seems to be working fine with both Hyperterminal and Teraterm. The way I did this was just run the binary of an already worked example and see that the serial connections are working fine. 

What I realized was that some changes need to be made to the code and some variables checked for the right value in the support files for the output to show properly through the UART.

 

After looking around extensively on the forums I actually solved this problem by following the thread here 

https://community.freescale.com/thread/42804

 

 Overall, just following the above thread solved this issue. 

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TomE
Specialist II

Hyperterminal always gies problems.

 

Put an oscilloscope on the serial output pin to make sure you're getting bits of some sort. Then you can measure the period of the bits to see if you've got the CPU clocking, dividers and baud rate right.

 

If you don't have one, write a loop that continuously transmits data and then see if you see a change on the serial output pin with a multimeter.

 

Make sure Hyperterm is set to the right serial port (COM1 or COM2 and not a modem. Click on the "on hook and off hook" telephone buttons. It tends to be fussy with the other modem signals - you might want to pull the unused pins DB9 pins up.

 

I'd suggest you forget Hyperterm and use Teraterm instead. it is easier to get working with embedded hardware.

 

http://www.ayera.com/teraterm/

 

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637 Views
net11
Contributor III

Thanks TomE. I checked the serial port connections and it seems to be working fine with both Hyperterminal and Teraterm. The way I did this was just run the binary of an already worked example and see that the serial connections are working fine. 

What I realized was that some changes need to be made to the code and some variables checked for the right value in the support files for the output to show properly through the UART.

 

After looking around extensively on the forums I actually solved this problem by following the thread here 

https://community.freescale.com/thread/42804

 

 Overall, just following the above thread solved this issue. 

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