SAM4S-EK UART DBGU Signal Collision?

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All,

I am creating custom board with the SAM4S and using the SAM4S-EK as a reference particularly the UART portion.

I noticed on the EK board, the UTXD0 (PA10) line goes through the RS232 transceiver and out to pin 3 on the DB9 (which is also a transmit line on the PC side).  Similarly the URXD0 (PA9) line gets connected to pin 2 on the DB9 (which is a receive data on the PC side).

 

This seems to have a signal collision.  Can anyone confirm that the UART on the SAM4S-EK board work?

 

Thanks in advance.

H.

Last Edited: Thu. Oct 15, 2015 - 11:34 PM
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You have to understand, an RS-232 connection has 2 ends, the "Terminal" and the "Modem." Both you EK board the the computer are "Terminals," so to talk to each other, they'll need a "Null Modem" in between. You can make one easily enough yourself, just swap the wires to pins 2 and 3 on one end of your cable.

 

When computers, terminals and printers spoke RS-232, you could go down to any Radio Shack (rest their soul) and buy a null modem. Even Wal*Mart had them. 

 

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