Asked — Edited

H-Bridge Controls For Roli Seem Broken

I'm going through the tutorials (this particular one is lesson 44), and something seems off. I've followed the instructions completely but the H-Bridge controls don't function correctly. Roli will move backwards just fine, but "Stop" causes the left tread to stop, "forward" causes total stop, right causes total stop and left causes only the right tread to move.

Any advice would be greatly appreciated.


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Hi @Angell

Sounds like you have your wires plugged in incorrectly. Could you post a picture of how you have them plugged in?

They should look like this:

User-inserted image

United Kingdom

If it moves when you try any direction then we can rule out the +5v and Vcc wire swap issue.

If it moves when you hit stop then there is a problem with the wires to In1 to In4. It initially sounds like you have the wires for both channels crossed causing both to be low or both to be high on some movement commands or you have a PWM connected to one of the In1 to In4s.

You may need to check on the H-Bridge in Roli and look at what colour wires are going to which pins. Make a note of them and ensure that they are connected to the correct digital ports on the EZ-B and ensure the control in ARC has the correct ports set.


I appreciate the quick replies on this. I looked through the discussions posted. I tried reverse wiring the H-bridge and that didn't solve it (just reversed the problem).

After changing the wiring to match the examples shown for how it should be wired, I'm getting no movement at all.

This is what it currently looks like. I'm not seeing any discrepancies from what other users have posted as their correctly wired units.

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Any further help would be greatly appreciated.

United Kingdom

Check your H-Bridge Movement Panel settings and make sure they are as follows;

Left Trigger A: D1 Left Trigger B: D2 Left PWM: D0 Right Trigger A: D3 Right Trigger B: D4 Right PWM: D5

Your wiring is correct for the above configuration (I have presumed the green wire goes to EnB in your photo).

Check the push switch on the H-Bridge is pressed down to enable the onboard 5V regulator.

Then move the sliders on the Movement Panel down to about 3/4 to initialise the PWM and try moving the robot with the movement panel. After this you can move them back to the top.

While using the Movement Panel see if any LEDs on the H-Bridge are lighting up. You should get two LEDs light up when you attempt to move in any direction (in addition to any LEDs which are currently lighting up).


Hi @Angell are you using the latest Roli Example in ARC 2014.11.30.00?

What Rich is mentioning will work, using the Roli example will just get you there quicker.


look at the motor wires (color),this video is from dj. User-inserted image


Sorry Nomad, that tutorial is not a good one to follow as it is wired to work with the ez-bv3. It is wired differently for the v4, see here.


Please follow the Roli HBridge Tutorial to verify that the wires are connected correctly:) Here is a link to the tutorial:

As for the wires directly on the HBridge (which is inside roli), there is a section at the bottom of the tutorial with images.


Thank you so much for all of your help everyone! My robot is fully functional now.


Rich posted above: Check the push switch on the H-Bridge is pressed down to enable the onboard 5V regulator.

This lesson indicates the same thing (

The lights on the H-Bridge only come on when mine is in the up position, and Roli only moves when it is in the up position.

Which way is correct?