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T100 random movements


#1

I’ve purchased 4 t100 thrusters for making my own rov. Basic escs are used to control the thrusters and arduino is used to send pwm signals to the escs. The arduino on the rov interprets signals coming from the RS485 module which is attached to the ps2 arduino system on the shore and gives out pwm signals to the escs. However, when the pwm of 1500 microseconds was sent, thrusters started to spin slowly, randomly, non-continuously, clockwise or anti-clockwise. Strangely enough , if i unplug the rs485 and uses the potentiometer to control, the thrusters works completely normal, i just wonder if the signals to the escs and arduino are the cause of problem.Any help would be greatly appricated, thx a lot!


(TCIII) #2

@Terence,

Are you using a setup like this: http://www.homebuiltrovs.com/rovforum/viewtopic.php?f=15&t=1130

I suspect that there are slight offsets from 1500us in the PS2 controller joysticks that are causing the T100 thrusters to spin at low speed.

Regards,
TCIII AVD


#3

Yes, my set-up is exactly the same. However, even I use the buttons on the ps2 to control the thrusters, the problem still occur. Is there another possible cause of problem?


(TCIII) #4

@Terence,

You probably need around a 50us dead band on either side of the 1500us neutral point.

I tried to find similar code that incorporated the dead band, but no luck.

Regards,
TCIII AVD


(Jacob) #5

You can add a low pass filter or deadband to input signal in your arduino program. We can’t help much without seeing the code that you are using.