Arduino Forum

Topics => Robotics => Topic started by: tnkumar on Dec 07, 2018, 01:13 am

Title: Powering servos - for Sainsmart 6DOF robot
Post by: tnkumar on Dec 07, 2018, 01:13 am
I have got a SainSmart 6 DOF robot (https://www.sainsmart.com/collections/robotics-cnc/products/6-axis-desktop-robotic-arm-assembled)

To play it safe, I ordered the shield from Sainsmart (https://www.sainsmart.com/collections/shields/products/sensor-proto-shield-for-arduino)

When I look at the schematics of the shield (http://s3.amazonaws.com/s3.image.smart/download/101-20-102/Schematic%20diagram.png), it does not show any active components (like transistors).

This lends me to believe that the pins of the arduino are directly supplying the control signal  to the servos.
Is this acceptable? OR do you need drivers?

The motors as specified by Sainsmart are MG966R and SG90
Title: Re: Powering servos - for Sainsmart 6DOF robot
Post by: slipstick on Dec 07, 2018, 09:54 am
Servo control signals direct from Arduino pins are no problem.

It's only the + and - power to servos that you need to be careful about and they come from the terminal block which is correct. You need to provide a suitable power supply (I imagine you mean MG996R servos and they take a lot of current).

Steve
Title: Re: Powering servos - for Sainsmart 6DOF robot
Post by: tnkumar on Dec 07, 2018, 10:37 am
Thanks Steve for the clarification that it is ok to connect servo signals direct from Arduino pins.
Title: Re: Powering servos - for Sainsmart 6DOF robot
Post by: jremington on Dec 07, 2018, 04:43 pm
Budget one Ampere per servo and you should be safe. So, a 5-6V, 6 Ampere power supply, or hefty rechargeable batteries would be good choices. Don't forget to connect all the grounds together.
Title: Re: Powering servos - for Sainsmart 6DOF robot
Post by: vinceherman on Dec 07, 2018, 05:10 pm
(https://cdn.shopify.com/s/files/1/1978/9859/products/01_101_compact.jpg?v=1499266747)

This looks like a handy shield.  Push it on to the Uno, put an appropriate power supply into the blue screw terminal block and plug in your servos.
Title: Re: Powering servos - for Sainsmart 6DOF robot
Post by: tnkumar on Dec 07, 2018, 05:26 pm
Thanks @jremington and @vinceherman
Title: Re: Powering servos - for Sainsmart 6DOF robot
Post by: Northof49 on Dec 07, 2018, 06:11 pm
An ATX computer power supply is a cheap source of 5v and 12v power.  Remove them from old computers, and jumper two of the appropriate pins to turn them on. 


https://makezine.com/projects/computer-power-supply-to-bench-power-supply-adapter/
Title: Re: Powering servos - for Sainsmart 6DOF robot
Post by: tnkumar on Dec 07, 2018, 07:27 pm
Thanks @Northof49