View Full Version : Sabretooth 2x10 - in p-serial mode

02-13-2007, 10:20 AM
I'm having a few problems getting the Sabretooth to respond to serial data.

I have a serial to TTL cable and I've wired the Gnd, Vcc and TX lines into 0v, 5v and S1 respectively.

When I power up the Sabretooth I get Status Ind 1 on, and that's pretty much it.

My DIP switches are set

1: Off
2: Off
3: On
4: On
5: On
6: On

Address = 128

I've tested my Serial <-> TTL cable on hyperterm, and when I connect TX <-> RX I get echo from the cable - so it seems to be OK.

I also wired in an 11K pot to the Sabretooth in Analog mode, and I got "steering" on S1 - turning one way turned motor 1 and the other way motor2 - so I think that the Sabretooth is working.

My software sends 170 - the bauding character first, but the light stays on and nothing happens.

Is there a packetized serial test app for the Sabretooth somewhere?

Oh yes, and I'm sending 4 bytes to the serial port like this:

byte[] _result = new byte[4];

_result[0] = 128; //Address

_result[1] = Convert.ToByte(iCommand);
_result[2] = Convert.ToByte(iData);

// Gotta use an int here
int i = _result[0] + _result[1] + _result[2];

_result[3] = Convert.ToByte(i);
_result[3] &= 127;

_serialPort.Write(_result, 0, _result.Length);

My port settings are 2400-8-N-1

Anyone got any ideas...?


02-15-2007, 04:21 PM
I've been asked to respond to this post as it was solved in private tech support emails. I am reposting the conversation here for public benefit:

When you send the bauding character, you should get a decrease in brighness of the status 1 LED (from a full bright "waiting" to a half bright "running)
We don't have a windows test app that's ready for public consumption, but I'll add it to our list of "documentation to add to the website"
The easiest way to verify that you have communication to the Sabertooth is to put it into simplified serial mode and start throwing bytes at it. If that works, then your PC-sabertooth link is working properly, and the problem is in the startup or packet stream that you're sending it.
Hope that helps. Let me know if you run into any more problems, and I'll do what I can to help you through them.

I managed to get it working but I had to turn off the FIFO buffers for the serial port. It seems that I can’t get the Sabretooth to respond at all when these are on.
Is there a “preferred” route when controlling the Sabretooth from a PC, maybe using a USB to TTL connector?
It also seems that I have to send the bauding character twice to switch the Sabretooth on.

Are you allowing the recommended two second delay between applying power and sending the bauding character?

Yes I am – making sure it has plenty of time. I always have to send the char twice – even from 3rd party applications.