Shop OBEX P1 Docs P2 Docs Learn Events
motor controller problems — Parallax Forums

motor controller problems

AnnoyingAnnoying Posts: 50
edited 2009-09-13 20:14 in Robotics
So my two robots each incorporate the HB25 motor controller, the RF Transmitter/Receiver modules, and an accelerometer, and I'm using the Basic Stamp 2. When the accelerometer value from the other robot is above a certain value (the receiver is constantly receiving the values)·the program instructs the motor to turn through the HB-25 motor controller. I'm having a lot of problems with this. The motor controller seems to be somehow interfering with the receiver-- I see the debug screen with all the accelerometer values from the other robot constantly streaming, and then I turn on the motor controller, and the values stop streaming. The motor only turns sometimes, and even with a simple program exclusively programming the motor controller, the motor inches forward very slowly and then goes full speed after about 5 seconds. sometimes the motor doesn't turn at all. it's just not consistent.·Have you ever heard of similar problems?
Thanks.·

Comments

  • TimmooreTimmoore Posts: 1,031
    edited 2009-09-10 19:58
    Try powering the motors and the stamp/accelerometer/radio off different batteries. It sounds like the motors are generating noise/power spikes/brown outs and interferring.
  • AnnoyingAnnoying Posts: 50
    edited 2009-09-10 20:29
    thanks for the reply but everything is worse than ever--now the sample HB-25 code won't even work, the transmitter/receiver sample code doesn't work (nothing shows up on the debug screen)...before things were very inconsistent and the sample code would occasionally not work. I have no idea how to debug this. I checked my wiring over and over again. Do you know how I can be sure that I have a faulty component? when everything "half-worked" I tested the motor through very simple code that made it turn one way, but when I modified the code to make it turn the other way, it didn't move. ahhhhhhhhhhhh!!!!!!!
  • TimmooreTimmoore Posts: 1,031
    edited 2009-09-10 22:18
    The -ve on both batteries need to be connected together.
    What I would do is disconnect power to the HB25, and plug the 3 pin to the HB25 to a servo instead and see if the servos move correctly. If that works then try the hb25 if that doesn't work it is either still a power issue or the hb25s have problems.
  • FranklinFranklin Posts: 4,747
    edited 2009-09-11 01:22
    If none of that works attach a drawing of your circuit and the code you are running.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    - Stephen
  • AnnoyingAnnoying Posts: 50
    edited 2009-09-11 23:06
    I took everything apart and just put together the simple HB-25 circuit, and it didn't work...I think the motor's noise damaged it...do you know how easily this can happen or if everyone normally uses a separate power supply for the motor controller? Is there any other way you think it could become damaged? and also is the Motor Mind B controller offered by Parallax any better? thanks...
  • TimmooreTimmoore Posts: 1,031
    edited 2009-09-12 00:49
    When you say didn't work, you mean the led on the hb25 didn't light and the fan didn't spin? Probably the easiest way to damage the hb25 is to connect power the wrong way round. The hb25 has a fuse - have you checked it?
    Do you have the specs/data sheet for the motors and what size (voltage) battery are you connecting the the motors?
  • AnnoyingAnnoying Posts: 50
    edited 2009-09-13 19:51
    wow I actually just found out what was wrong--I have been using rechargable Ni-MH batteries and once I switched to a normal Alkaline, it worked!! even though the Ni-MH batteries were fully charged, I guess they couldn't deliver enough current or something...thanks for your response!
  • TimmooreTimmoore Posts: 1,031
    edited 2009-09-13 20:14
    Ni-MH and other batterys have a discharge rate. Normally the cheaper the battery the lower hte discharge rate - basically they use less metal for the anode/cathode which increases the resistance which decreases the current. So you can probably find nimh that will work but either find one that gives the discharge current or look at the physical size the high discharge ones tend to be larger.
Sign In or Register to comment.