Servo SG90, need help

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vader
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Servo SG90, need help

#1 Post by vader » 26 Jun 2017, 16:24

I've read the wiki and I can control the SG90 with the servo command, but only up to 180°. So my questions are:

1. Is there a device to be installed in the task table for the servo?
2. Why are the servos identified with ID (e.g. servo,1,14,0), when the command direct control the GPIO?
3. How is the command for 181° and up?

Thanks for any help.

PS: The servo command is twice in the wiki command reference!

Shardan
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Re: Servo SG90, need help

#2 Post by Shardan » 26 Jun 2017, 19:30

vader wrote: 26 Jun 2017, 16:24 I've read the wiki and I can control the SG90 with the servo command, but only up to 180°. So my questions are:

1. Is there a device to be installed in the task table for the servo?
No. It is just controlled by HTTP-commands, no device setting.
2. Why are the servos identified with ID (e.g. servo,1,14,0), when the command direct control the GPIO?
Can't say why. Maybe a developer can say something about it.
3. How is the command for 181° and up?
Ooops - something about servos in general:
There are a lot of servos on the market. Most of them are not able to turn full 360°!
Following the datasheet of SG90 ( http://www.micropik.com/PDF/SG90Servo.pdf )) this servo
can turn about 180°.
From the datasheet:
Servo can rotate approximately 180 degrees (90 in each direction)
If you try to turn more then 180° it starts humming and vibrating and gets somewhat hot - the motor tries to turn more
then the stoppers in the gear allow.

There is no special command for > 180°, it's same command. Just the servo can't turn that far.

Regards
Shardan
Regards
Shardan

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vader
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Re: Servo SG90, need help

#3 Post by vader » 26 Jun 2017, 19:51

Ah, ok,I didn't know that. There was no hint in the item specification for this limitation. Thank god, that I only payed 1.55€ for it. :lol: Thanks anyway for the infos.

Shardan
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Re: Servo SG90, need help

#4 Post by Shardan » 26 Jun 2017, 20:08

Don't ask why i know that :oops:
I stumbled into the same trap.
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Shardan

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vader
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Re: Servo SG90, need help

#5 Post by vader » 26 Jun 2017, 21:33

I would bet, we are not the only two.... :mrgreen:

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toffel969
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Re: Servo SG90, need help

#6 Post by toffel969 » 27 Jun 2017, 14:08

vader wrote: 26 Jun 2017, 21:33 I would bet, we are not the only two.... :mrgreen:
no... make that 3 already :mrgreen:
Domoticz on Raspi 2 -- 14 ESP units (hacked Sonoff,NodeMCUs, Wemos, self-built units) running with RC140- Mega 2.0.0 dev8

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