Ultimate 2.0 Bluetooth Disconnect after running either wheel motor

#1

I have a recent Ultimate 2.0 kit and built the basic gripper arm robot. I also have the most recent version of the app on my android phone. It worked great. Then I tried a few basic programs and loaded and tested those successfully. Now I want to restore the default software so I can demo for a friend (grandson). I have successfully reset the firmware and reset the default program several times. Batteries are newly charged. When I load the app and it synchronizes successfully I can clamp and unclamp or raise and lower as long as I want. But when I move the robot in any direction the Bluetooth immediately disconnects. Any ideas? Thanks!

Gary

#2

Hi gmeyer1357,

What’s kind of batteries do you use? Since you mentioned that they are newly charged battery, they are rechargeable lithium battery?

Since from the situation you mentioned, I still suspect if the battery discharge enough power stably? If you have the other battery have a try or do you have a good quality power adapter (12V/2A) have a check.

#3

Very good suggestion! I tried brand new non-rechargeable Alkaline batteries (like I initially used when it worked fine) and see exactly the same behavior. But I agree with you that a power problem sounds like it could be causing this issue. I will buy a power adapter and see if that helps although that would suck to have to have a power cord attached to the robot at all times. I wonder if I have a faulty motor?

Gary

#4

Hi gmeyer1357

If you were using non-rechargeable battery before.
I may suggest that you buy rechargeable lithium battery (7.4V is ok) from amazon or local shop have a try since it won’t be convenient to control the robot with power cord connected to a power adapter.

To test if the motors on the Ultimate wheels work or not. You can test it with a mBlock program:

  1. Upgrade firmware for Ultimate 2.0 first refer to this instruction.How to Upgrade Firmware for MegaPi.zip (252.4 KB)

  2. Then test the following example program:

    Pasted image706x395 31.6 KB

#5

OK, I am going to try some other batteries and the adapter power and will let you know. Thanks for the sample code. But I know all three motors run. My concern is that one of them may be causing a battery drain spike when starting up which causes the Bluetooth disconnect. I don’t have the necessary electronic test equipment to measure that. I will continue to research this perplexing problem.

Gary

#6

I bought top of the line 1.6 V chargeable batteries and this extended the time the Bluetooth stayed connected from 20 seconds to 40 seconds. Today I used a plug in adapter and now the bot never loses Bluetooth connectivity, so it is definitely a power issue. Unfortunately I don’t have the correct test equipment to measure the actual drain from each motor, but this bot definitely does not like batteries. Attaching a power cord is definitely a bummer but I can still use it to play with some programming as long as I stay away from using the big motors. Let me know if mBlock ever makes some better motors available that can work with batteries. Thanks!

Gary

#7

Hi gmeyer1357,

Do you use 6 X rechargeable battery(1.6V for each battery)?
Normally, it works with the suggested batteries. Here we use such kind of battery bought in China for testing and the Bluetooth connection works stable.

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#8

Yes, 1.6 v for each battery. I will just keep the bot tethered until someone finds a good battery. Let me know if you find a reliable source for your 7.4 v Chinese battery with a compatible charger and I will give it a try. Thanks for your help.

#9