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New Robot Does Nothing - Printable Version

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New Robot Does Nothing - Droidurlookingfor - 05-18-2017 12:00 AM

I got my robot assembled. When I turn it on, the arm moves a few degrees, and that's all I get.

I'm trying to find info on how to debug it and so on. Can someone give me some clues to get me started? I've written a few Arduino sketches, but I am not a robotics or programming expert.


RE: New Robot Does Nothing - JohnQ - 05-19-2017 11:03 AM

(05-18-2017 12:00 AM)Droidurlookingfor Wrote:  I got my robot assembled. When I turn it on, the arm moves a few degrees, and that's all I get.

I'm trying to find info on how to debug it and so on. Can someone give me some clues to get me started? I've written a few Arduino sketches, but I am not a robotics or programming expert.

Take a look to the very end of this webpage: http://www.jjrobots.com/b-robot-evo-kit-assembly-instructions/
the debbug options are explained there

Could you upload photos of your setup? looks like the motors are now getting any command (stepper motor drivers problem, cables...?)


RE: New Robot Does Nothing - Droidurlookingfor - 05-19-2017 02:32 PM

(05-19-2017 11:03 AM)JohnQ Wrote:  Take a look to the very end of this webpage: http://www.jjrobots.com/b-robot-evo-kit-assembly-instructions/
the debbug options are explained there

Could you upload photos of your setup? looks like the motors are now getting any command (stepper motor drivers problem, cables...?)

Thanks for the help. I was getting worried.

I saw the stuff about debugging, but I have no idea where that code is or how to get it into the Leonardo. I have the library folders from Github. I opened some files up, but I didn't see what I needed.

I can try to take some photos, but I made sure I installed the cables correctly.

It's a real pain hooking the bot up to the computer. I would humbly suggest the sellers make a hole in the side plate large enough for a USB cable to pass through. Right now, I have to take the whole robot apart to connect it. I'm thinking I'll just cut the robot to provide access.

They also need to change the arm so it fits the servo horn. I had to grind the horn down about 1/8". Also, the screw that attaches it is too short.


RE: New Robot Does Nothing - Droidurlookingfor - 05-20-2017 10:42 PM

I'm trying to get this thing going on my own. I decided to make sure the code had been uploaded to the Leonardo. I opened BROBOT_EVO2 and tried to upload it. Arduino refuses to upload it, saying "'Serial1' was not declared in this scope." Now I am stuck.

What progress I have made. I found out the Arduino window I was using had the wrong board specified. I changed it and uploaded the EVO 2 sketch. Now the robot makes a howling sound, and one wheel turns slowly while the robot lies on its face. I guess the plug and play robot I bought wasn't actually plug and play. Someone may have failed to program it.

Not sure why it lies on its face and howls. I may try uploading the original software.


RE: New Robot Does Nothing - JohnQ - 05-22-2017 12:17 PM

Check you have selected the correct board (Arduino Leonardo) in the Arduino IDE "tools" menu. Oh, I just saw your second message...

Check two things:
1) The batteries are ok (use new ones)
2) the stepper motor drivers are delivering all the current they can. Take a look to this image: http://www.jjrobots.com/wp-content/uploads/2015/06/A4988-adjusment1.jpg Try adjusting the output power rotating the screw (but first check the motors are properly connected and the same for the stepper motor drivers!: check the headers)


RE: New Robot Does Nothing - Droidurlookingfor - 11-26-2017 12:58 AM

I had to run out to get some fries, but I'm back now.

I just turned the robot on again. This time, it did nothing for a while. Then it tried to move around. Instead of balancing, it flipped onto one side and then flipped onto the other. Then it lay on its side making a high-pitched noise.


RE: New Robot Does Nothing - Droidurlookingfor - 11-26-2017 02:32 AM

Got it working.

For some reason, my IMU has to be oriented 180 degrees away from the position in the instructions. It was accelerating in the wrong directions to regain balance, so it always ended up on its side.


RE: New Robot Does Nothing - JJrobots JP - 11-27-2017 10:13 AM

That is strange... the only reason to have to do that is that the motor cables were swapped or the stepper motor cables polarities reversed :-\


RE: New Robot Does Nothing - dali - 01-02-2018 05:07 PM

Hi. I have just built a B-Robot from a kit and it behaves exactly in the same way as the author of this thread describes. My son has built another one from a different kit in the same time and again it does nothing.

What I can observe after switching it on:
- green power LEDs on both Arduino and the shield are on
- blue LED flashes once
- the microservo moves for maybe 10 degrees
- nothing happen then
- it is possible to connect to the robot via wifi but it does not react

I have tried to increase the power for motors (clockwise for about 30 degrees) with no apparent result. I have not touched the IMU yet because it seems to me exactly same as pictured in the assembly video.

Any help appreciated.


RE: New Robot Does Nothing - JJrobots JP - 01-02-2018 06:26 PM

Hi Dali,
When you say "in tha same way" you mean you had to rotate the IMU 180º?

Looking at the photos, the stepper motor drivers and IMU are placed correctly . Everything seems to be fine. I can not see how the motor are connected but that does not really matter right now.

Let´s check some things
1) Are you using alkaline batteries? Very low voltage batteries will not have enough power to move the wheels
2) If you lift the B-robot, does it spin the wheels?
3) Can you swap the IMUs of the B-robots and see if they behave the same?
4) Does the led on top of the IMU lights after switching the Brobot ON?

The IMUs are quite sensitive but it is extremely unusual that 2 of them fail at the same time...