Serial Port data dumping program

[Paul Hamilton]

Hi,

I am trying to debug a Mini SSC FreeBSD program that I am trying to write.
It would be nice to be able to be able to see what is being transmitted.  It
would help in the debugging of my program.

Here is a link to a Windows based Mini SSC program:
http://www.rentron.com/Mini-ssc.htm  Using this, I can control the servo, so
I know the hardware and cables work etc.

I have been using the 'minicom' port to dump the received data.  However, it
doesn't seem to collect the data properly.  Data coming in should be in
accordance with the SSC protocol, ie:  

byte 1:    0xFF    // sync byte

byte 2:   0x01 - 0x25f    //servo address

byte 3:   0x00 - 0x255   // servo position

Here is a dump of the collected data (via minicom):

#hexdump  minicom.cap
0000000 45ff 49ff 4cff 50ff 53ff 57ff 5aff 57ff
0000010 53ff 50ff 4cff 49ff 45ff 45ff 01ff ff82
0000020 8101 01ff ff80 8202 02ff ff81 8002 03ff
0000030 ff83 8203 03ff ff81 8003 7fff 7fff 7eff
0000040 01ff ff7f 7f02 03ff ff7f ff7f 8001 02ff
0000050 ff80 8003 04ff ff80 ff80 8006 07ff 0080

Looking at the first row of data, it is only showing two bytes, sync and
servo position.  Rows 020 and 030, shows some servo addresses, but
sometimes, together!  Both the mini-ssc.exe and minicom program are using
9600 8n1, so why is it showing this?  Is there something I have missed in
the setup of minicom?  Looks like this is a serial buffer problem.

Is there a better program I could use to display the incoming serial data in
hex?

NOTE:  I only use two wires, signal ground and Tx Data (connected to the Rx
Data).  The servo does respond correctly, so I know the serial data must be
in the correct 3 byte format.

Looking fwd to your thoughts.

Cheers,

Paul Hamilton