SSC-32U Pulse Width Modulation

Question

A quick question. If have a couple of 270 degree servos. To get the full rotation I need to set the pulse width range in the SSC-32U configuration to 500-2500. Will this upset other standard 90 degree servos connected to the SSC-32U? The default range on the config was 650-2250, and I was only getting about 220 degrees rotation.

DJ Sures · Answer

The standard servos should adapt for it

afcorson · Answer

Thanks. I didn't want to risk upsetting my InMoov fingers and those 10 servos.

DJ Sures · Answer

The pwm of a servo is supposed to be standard - buuuuuuuut a bunch of low cost servos began changing their pwm range. And different models and manufacturers did as well. So now it’s just a disaster out there of different ranges

afcorson · Answer

Well everything worked perfectly yesterday. Today something has changed. Perhaps Covid has struck down my SSC-32U as it will not move any servo. I have checked the following: BAUD rate set to 38400 on the SSC-32U and in the Control settings in ARC; connection to RX/TX/Gnd all correct as they were before; servo correctly connected- tested different ones; swapped EZB for another - no joy; changed PWM settings back to 650-2250 - no joy. I am getting a green light on SSC-32U indicating it is receiving data. So I am at a loss to know why the connected servo ain't moving. Wish I has another SSC-32U to test, but I don't. Any ideas?

DJ Sures · Answer

Are the servos getting power? Maybe the ssc has a fuse?

afcorson · Answer

The SSC-32U user manual doesn't indicate it has a fuse. I don't think the servos are getting any power. I have contacted the supplier about my problem. I tried connecting it to my laptop but couldn't install the drivers or get a Coms port. I think that is Windows 10 though. Meanwhile I have ordered a replacement.

DJ Sures · Answer

Wonder if one of the traces on the pcb burned out. Could have been too high of a current draw. Take a close look at the pcb and follow the positive and negative traces to the I/o pins and power supply connection. See if anything looks out of sort

afcorson · Answer

I am getting the correct voltage through to the I/o pins on all the ports I am using on the SSC-32U. I haven't checked to signal pin though. I imagine I'd have to send data from the EZB to get any current on that pin. Would that be worth doing? PS. Just did a voltage test on the control pin on one of the SSC-32 ports by sending a couple of commands from ARC. I got zero voltage.

DJ Sures · Answer

If the servos are set to full 180 degrees, that would read a bit of voltage on the signal pin. If the servo for the pin is not set for a position, the voltage would be zero.

set the servo position before checking voltage on the signal pin. Let me know what you find

afcorson

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