tBB Troubleshooting Support

If nothing turns on after installing the batteries there is no power coming from the batteries into the Arduino

Try the following:

• Check that that batteries are installed correctly in the battery holder.
  • If you have a multimeter (recommended) use it to test the voltage coming from the battery pack.  If no voltage is detected the issue is in the battery pack.
• Check the alignment of the batteries and the connection of the batteries to each terminal on the battery holder.  Use a flat screwdriver to “pry” the batteries from the spring side ensuring each battery is making contact at both ends
• Ensure the barrel connector is properly inserted into the power jack of the Arduino. 
• Try a different power harness to see if this resolves the issue.

If the Arduino and motor shield are getting power but not the motor controller, the issue is in the wiring from the Arduino to the motor controller

Try the following:

• check that the red wire is inserted fully into the Vin pin on the sensor shield
• check that the red wire is fully inserted and tightening into the VCC terminal on the motor controller
• check that the black wire is fully inserted into a GND pin on the sensor shield
• check that the black wire is fully inserted and tightened into the GNG terminal on the motor controller

This is more than likely a loose wiring/ connection issue.  If the connection between the sensor shield and the Bluetooth module is not solid the Bluetooth can disconnect when the robot moves, hits a bump, etc. 

Try the following:

• Check the battery level – if the batteries become drained this can cause a “brown out.” There is enough power in the system to make the connection but once the motors turn they draw all the power away from the Bluetooth module, causing it to disconnect.  A minimum of 6v is recommended.
• Check the wiring harness from the sensor shield to the Bluetooth module.  Be sure all the wires are fully plugged in and are tight.
• You may need to replace the wiring harness, after a while the connection can become loose.

The most common cause of this issue is that the Bluetooth wiring from the sensor shield to the Bluetooth module is backwards.

Try the following:

• FIRST: Shut everything off, try reconnecting and restarting tBB and the controller
• Double check that there are no crossed wires between the Bluetooth wiring clip and the connection on the sensor shield (refer to the Electronics Assembly Guide)
• Check that the TX and RX pins on the Bluetooth module go to the TX and RX pins on the sensor shield
• Try flipping the Bluetooth module and connecting it backwards (this might mean removing the Bluetooth clip from the chassis temporarily)
• Try a different Bluetooth module
• Try replacing the Bluetooth wiring harness

THIS IS A SHORT CIRCUIT –   This is a serious situation that must be dealt with immediately. It means that electricity is flowing uncontrolled and without resistance in the electronic system.

DO ALL OF THE FOLLOWING BEFORE TESTING THE ROBOT AGAIN

• Remove the battery pack and the batteries.
• Remove all batteries from the battery pack and inspect for damage.  (burn marks, bulging – damaged batteries must be discarded)
• Reinstall all batteries, ensure that all batteries are installed correctly
• Double check that none of the batteries were installed backwards 
• Carefully inspect the power harness and replace if needed
• Reconnect the power harness (barrel connector and battery snap)
• Turn on power switch and observe
• Shut down and redo all steps if the problem persists

When driving tBB one of the motors won’t turn a certain direction, but the other motor seems to be working fine.   This situation is almost always a wiring issue.

Try the following:

• Carefully check that the 4 wires going from the motor controller to the sensor shield are connected to the right pins (white terminal on pins 3,5,6,11)
• Check for a snug fit of the wiring harness on the pins, if they are loose or come off easily you may want to replace a single wire (or the entire set)
• Check the connections from the motors to the motor controller to ensure proper connection, try removing and reinserting the motor wires into the motor controller

Sometimes the motor wiring doesn’t match the code resulting in one or both motors spinning the wrong direction (backwards instead of forwards).

Try the following:

• Check the wiring harness from the motor controller to the sensor shield, make sure wires are not crossed
• Swap the wires on the motor controller connected to the affected motor

There are several reasons why a servo might not be working.  The most common are wiring issues, coding issues and possibly a broken servo.

Try the following:

• FIRST: check the servo wiring making sure the servo is on the correct pin and the wires are connected in the right orientation
• SECOND: try a different servo (this will help eliminate a broken servo being the cause)
• THIRD:  check the code for errors (this is the most complicated to solve so do the easy stuff first)
  • Check the servo setup
  • Check the servo functions
  • Check the main loop where the servo functions are being called

This is caused by the servo motor not being at the proper degree/location relative to what it should be based on the code.  If the code is trying to set the servo to 90 degrees but it is only at 85 degrees, the Arduino continues to send power to the servo trying to make it move.  This can cause humming, buzzing and heating.  Eventually the servo will burn out.

Try the following:

• Inspect the servo set up and make sure there is nothing stopping the servo from moving into the correct position and remove any obstacles
• Connect tBB to the computer and use the serial monitor to get a read out of the current servo degrees, change the servo function limits to match any physical limitations on the servo
• Check the weight and strain on the servo, micro servos are designed for lightweight work, if you are trying to lift too much weight with the servo it will not be able to move to the specified location
• Consider redesigning the attachment you are controlling with the servo (can you make it lighter?)