Sabertooth 2*25 giving error light when running on load

Help & Support Robot Parts
1

Hi,

I am building a self balancing vehicle the configuration is sabertooth 225 to arduino uno and 2 wheelchair motor with 212V 12amps battery in series. sabertooth is in packet serial mode 1,2 OFF and 3,4,5,6 ON at 9600 baud rate.
When I run the motors with no load on a stands everything works fine and no error light just the blue status 1 led turns on.
If I put down on the floor with no load the bot balances with the error led glowing intermittently but is able balances on it’s on after tuning the parameters.
After adding some load on the bot about 65 lbs and the error led is more or less continuous and especially when changing directions.
I thought the battery were depleted so I recharged them but no change. Rechecked the wiring for shorts or loose end and everything seems OK.
Have a spare 232 sabertooth which I put instead of the 225 balance bot run as expected and the error led light does not glow and the bot balances with the same 65lbs weight on it without any issues.
I placed the 225 back in and things were as before. I am trying to figure out why the 225 is giving error light and not the 2*32 with everything being same.

Hoping for some help from the experts to get to the root of the issue.

2

forgot to mention pins config sabertooth s1 is connected to Arduino digital pin 11 and 0V to ground of Arduino.

3

This is most probably showing an over-current warning. Since you do not have the same issue with the 2x32 that’s probably confirming it.

From the Sabertooth 2x25 user manual:

The red Error LED illuminates if the Sabertooth has detected a problem. It will light if the driver
has shut down due to a depleted battery or due to overheating, overcurrent or overvoltage. If you
are using a NiCd or NiMH battery, and commanding an acceleration causes the motor to jerk and
the Error LED to flash on and off, the battery is depleted.

:slight_smile:

4

Thanks for the reply.

That was my conclusion too but was going to measure the current draw from the motors to verify but due to time crunch decided to use the 232 for now.
Have different issue after making the frame and assembly the 232 has stopped responding to the signals.
The power led is blinking but no motor movement and no error light except at power on to detect no of batteries.
Battery is charged and dip switched set according to the dip wizard for packet serial mode with emergency stop as follows
1-off, 2-off,3-off,4-on,5-on,6-off. (Worked fined with these setting before reassembly)
There is voltage of 8volts across motors leads and battery shows 25volts. 5volt output pin reads the same.
I put back the 2*25 this time to see if connection are a problem but the bot runs as it did before, so the connections and the code seem to be working as it should.
To see if the controller had any issues I tried to run the motors using analog mode with a potentiometer
0v of controller connected to grnd of the pot
5v to power and
signal to s1 and changed the dip switch to 1-on,2-on,3-off, 4-on,5-on,6-on based on my understanding of the document and Still no movement in the motors.
Not sure how to proceed with troubleshooting looking for some pointers or corrections.
Attached couple of images of voltage measurement.

Thanks

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image.jpeg2448×3264 1.36 MB

5

According to your dip-switch setting (1-off, 2-off,3-off,4-on,5-on,6-off) the last switch (6) enable the emergency stop feature.
You might just want to disable this and do a quick test.

DIP Switch 6 enables or disables emergency stops:
If DIP switch 6 is in the OFF position, emergency stops are enabled. This emergency stop is active low
and internally pulled down. To enable the M1 output, connect the A1 terminal to 5V. To enable the M2
output, connect the A2 terminal to 5V. If these connections are broken and emergency stops are
enabled, the motors will stop immediately. This might be used for a safety E-stop in a machine, to only
allow motion while a dead-man switch is held, or to detect a disconnected control cable.

6

Hi,

I tried that but no change. I also tried dip switch combination of (1-on,2-on,3-off,4-off,5-off,6-off) packet serial mode from 225 which I guess is legacy packet detail mode in 232 and worked before I decided to add emergency stop option still no movement.

Anything thing else that I can try?

7

For the both we get this configuration for Serial Packetized and no battery protection:
OFF - OFF - ON - ON - ON - ON

Quick Links:
Wizard for Sabertooth dual 25A motor driver
Wizard for Sabertooth dual 32A motor driver

Have you tried other serial modes ?
Have you tried to connect your 2x32 directly by USB and control it there ?

At this point you might want to contact DimensionEngineering as they will be quicker to find your issue.
Email: [email protected]
Support: help.dimensionengineering.com

8

I went back and checked the dip switch on the controller and it is OFF-OFF-ON-ON-ON-ON .
Sorry abt the goofup.

I haven’t tired controlling it through USB will try that as well as get in touch with dimension engineering team.

Thanks for the help.

9

I do have tge very same issue with a sabertooth 2x32. It’s a segway… under no load (no wheels engaged just motors) no issue, if i connect wheels as soon as the load increase it goes crazy and start full power… scary :wink:.
Dinension engineering said something on this?
Best regards
Gabio