Motors connected to Port 3/4b dont reliably function


#1

Apologies if this has been answered elsewhere,

I have built the Robotic arm tank and using the started basic mobile app to test it actually works. What I find is that when I first start the program (Android) and use the controls the tank will move but the arm + gripper controls wont respond. If I enter design and inspect the code of the button (no changes) then switch back to ‘Play’ the gripper and arm will work for a few seconds then stop. If I switch back to design/inspect code, the arm/gripper functions again.
Finally whilst the tank drives, I have noticed it drives a little skewed (one motor seems to be faster than the other) and occasionally controls respond erratically (e.g. turn left when should be moving forward) - however unlike the gripper/arm I haven’t nailed down when it happens/reliably recreate it.
Any ideas?
I intend to use the connect directly to PC later this week to play with it further!
Thanks for any help
Iain


#2

I am having exactly the same issue. I’m very curious to hear the response. I should also mention that this was not a problem a few weeks ago.


#3

Hi imaclean

Do you have the Ultimate 2.0 robot with MegaPi board?
First, please make sure you have connected the wires all correctly:

Second, please reset default program for the robot with latest version mBlock software 3.4.6, refer to this document to reset default program.How to reset default program for MegaPi.zip (363.1 KB)
Then try control the robot with latest version Makeblock APP either.

Once still the issue, I’d suggest that you change the batteries for the robot have a try. According to our test and research, it is suggested to use rechargeable Li-ion battery or rechargeable nickel-metal hydride, nickel-cadmium which can be bought from amazon or local shop. Or Alkaline battery with good quality like Energizer, DURACELL.


#4

I got the Ultimate 2.0 kit a couple of weeks ago and I am having exactly the same problem with the Robot Arm Tank. When I first ran it, everything worked fine (though I did lose connection between my Android phone and the MegaPi once). When I went to use it yesterday, the movement works but the arm doesn’t. It will work once and then stop.

For instance, I turned it on, started the app, moved the tank around, and pressed Arm Down. The arm went down all the way even though I had only briefly tapped the button. After that, it refused to respond. I could still move the tank but the arm and claw were non-functional. If I closed and restarted the Android app, the same thing repeated. The arm and claw would respond once and once only.

One time, I told the claw to open, which it did. However, the claw motor wouldn’t stop! It reached fully opened and then kept going, clicking and clicking until I shut off the MegaPi.

This all sounds to me like an Android app problem rather than a hardware problem, but that’s just an initial guess. This is definitely not a battery issue though. I’m using quality Energizer batteries and they have barely been used.

Chris


#5

Hi chrisv,

Here we tested both the Ultimate 2.0 and the Makeblock APP, it works as supposed.
I may still suspect the issue is on the battery you use. Are the Energizer batteries you using the rechargeable batteries?
If it is possible for you, please kindly try the rechargeable battery since the robot consume power fast.


#6

There is a bug in the android Makeblock app v2.9.3.
I can easily create it on both my Samsung Galaxy S7 and my Lenono Yoga Tab
When running the “Robotic Arm Tank” in Ultimate 2.0 the Unclamp/Clamp/Arm Down/Arm Up
only works a little time and then stops working. The joystick always work.
I have verified by modifying the Firmware_for_MegaPi.ino to send debug info over USB
that the android app simply don’t send any commands at all when the buttons stops to work.

As imaclean told there is a workaround to make it work but only for a little time.

  1. Open App and go to “Robotic Arm Tank”
  2. When the buttons stops to function go to Design mode
  3. Push a button, e.g. “Unclamp” and push “Code”
  4. Don’t change anything, just go back
  5. Push "Play"
    Now the buttons work for a little time and then malfunctions again
    Repeat from 2.

I can’t find the android app on github, only a pre-beta version,
so I can’t debug the client side.

The problem was there even when I switched to completely new (non-chargable) batteries.
Unfortunately ultimate 2.0 doesn’t seem to work with rechargeable batteries.
When I try with Ikea NiMH batteries fully charged I can’t get the Bluetooth to work


#7

Hi Andye,

The Makeblock APP 2.9.4.1 will be updated on Play Store in one or two days, please kindly try it then. Thanks for your feedback!


#8

Got the app update yesterday, and tested today with new batteries and now everything works as expected.
Thank you for a great product!


#9