Serial Port Bug?

Karl Larsen k5di at
Wed Nov 28 19:43:05 UTC 2007

David Timms wrote:
> Karl Larsen wrote:
>>    Wanting a way to test the serial port I recalled minicom and after 
>> getting it set up on /dev/ttyS0 it seems happy with Com 1. The old 
>> /dev/modem is gone on F7. But now what is a way to drive the serial 
>> port pins to a constant plus voltage with minicom?
> In minicom it can help {and if only using a 3 wire cable be required} 
> to disable the setting where it looks for HW handshaking from the 
> remote device:
> | A -    Serial Device      : /dev/ttyS1
> | B - Lockfile Location     : /var/lock
> | E -    Bps/Par/Bits       : 9600 8N1     | F - Hardware Flow Control 
> : No
> | G - Software Flow Control : No
> If you are using a cable with more than 3 wires, you might need to 
> check that the DTR, DSR lines a wired up appropriately - ie that the 
> remote device is not incorrectly telling your computer that it is not 
> ready.
> A simple trick is to connect pins 2 and 3 {transmit and receive} 
> directly on your serial port, and see if you get characters typed 
> echoed back ?
> DaveT.
    Excellent Dave! I have an extension cable on the serial port so that 
will be easy :-)

Get back to with results soon.

The results are with pin 2 and 3 shorted together minicom still did not 
print what I pressed. I turned on local echo and I see what I type but 
with the pin 2 and 3 shorted I still get just one letter.


	Karl F. Larsen, AKA K5DI
	Linux User

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