While stepping through a movement sequence on my BRAT I sometimes lose power to 1 or more servos for a moment and the robot sags a bit. When I go to the next step it really kicks when the servos move to the new position.
Is this a known problem or might it be unique to my board?
Thanks, Harry
maybe ur battery is low, thats the same thing that would happen to mine, power cuts in a strenous move, then come back, after a bit and stays after i finish that sequence
also have you updated the firmware on yours?? I seen that more with the 1.03 that is shipped with it.
You probably need to put a voltage meter across your battery/servo power supply and monitor for significant voltage drops during the servo movement.
I’ve got the latest firmware and it happens with a fairly full pack. I’m not really sure if it’s happening to just one servo or all of them since I’ve only noticed it on a particular servo.
I’ll have to watch for it and try to identify what is actually happening. I’ve got an amp meter that I can try to hookup to see if it registers anything.
Thanks for the suggestions, Harry
It’s definitely a power issue.
For whatever reason, be it faulty connections or low batteries, your servos are drawing more current than is available.
First check your batteries for voltage drops during this time, as zoom has said.
This will confirm that the above is the case.
Are you using a batery pack bought from LM or one you made yourself?
What AWG are the wires that you have going from the pack to the electronics?
Are you using a switch that’s rated below the current that your servos are drawing?
First check the batter to see if there are any drastic change in voltage, Then give each servo a label (Duct tape will do) with the pin # they are plugged into. After you labeled them, try and swap the servo thats messing up with a good working servo. If you notice the good working servo is messing up and the bad one is fine then that means your servos are fine and there is something wrong with the code or the SSC-32. There may be a short somewhere or something like that might be wrong. Though I think that the SSC-32 along with all Lynxmotion parts are high quality and wouldnt break.
-robodude666
Thanks for the suggestions guys. Had compamy over for the day and the little BRAT didn’t get much attention. May happen today too, a little RC combat scheduled.
The pack and switch are both Lynxmotion issue. AS soon as I have a bit of time I’m going to try to nail down what is raelly happening.
Cheers, Harry
Here are some things to keep in mind…
You are using digital servos. They will hold position even if the pulses are removed. This “feature” can make things really confusing. If you are teaching the robot and have to quit for a while, you simply power down the bot. When you get back to teaching you turn the bot back on, but the SSC-32 isn’t sending pulses until the Sequencer needs to send a new servo destination. So some of the servos are holding the wrong position. To fix this, click on the ambulance icon, once, then again. The first click removes the pulses (which are already interupted because the SSC-32 was reset, then the second click re-enables the pulses, which will put the robot back to where it was before you stopped teaching the bot.
Because I know you are using digital servos, I don’t think it is causig the problem you mentioned. Because they are digital, they always hold position in every case. Even if the pulses are removed. I think the only possible problem has to be a power interuption, or a defective servo. Sorry… But that’s what the evidence is pointing to. 
Thanks Jim. I’ve spent the last while trying to recreate the problem and have been unable to.
I’m starting to suspect that this may have been caused in my earlier efforts when I was just trying to figure out how everything linked up. I did lots of power ups and downs and clicking of buttons and I kept looking for the “UNDO” button. 
Thanks to all the others who helped too. Harry
