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Topic: Micro Servo and Optocoupler (Read 217 times) previous topic - next topic

Eduardojls

I´m trying to connect a micro servo to Arduino, but I don´t know why should connect an optocoupler when using the micro servo?  NOTE: The micro servo Í´m using is a SG90.

surepic

If arduino can supply 5v or even 3.3v logic then there is no need for any extra things.

Attach pwm pin of arduino to signal pin of sg90(yellow wire). And from external power source attach gnd and vcc to brown and red wires.

And tie gnds together.

Load servo example and test.

groundFungus

Quote
Attach pwm pin
A servo does not require a PWM pin.

slipstick

I´m trying to connect a micro servo to Arduino, but I don´t know why should connect an optocoupler when using the micro servo?  NOTE: The micro servo Í´m using is a SG90.
A servo rarely if ever needs an optocoupler so the question is what has made you think that you should be using one?

Steve

surepic

#4
Jul 15, 2019, 11:49 am Last Edit: Jul 15, 2019, 11:53 am by surepic
Groundfungus sg90 requires signal pin to operate. That pin goes into input pin of pic12f675 inside the sg90. Vcc goes into ldo regulator and regulator provides power to that pic. Before regulator its going into drains of mosfets. Gates of all 4 mosfets are attached to pic. I phisically opened few of towerpro mg series servos and reverse engineered the circuit for my projects.
For reference the ones that i had had tl33b regulator inside.

So i didnt get how sg90 will work without providing signal.

Thanks

slipstick

The point that groundFungus was making was that the Servo library does not need to use the hardware PWM pins. It can and does provide a servo signal on any digital pin.

So you're right that the servo needs a signal. It just doesn't have to come from one of the PWM ~ pins.

Steve

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