Can arduinos run three servos with flex sensors?

[brian.thomas]

Hi community,

I’m hopeful you can help me here - I’m trying to have students do a robotic prosthetic using some sparkfun flex sensors, PowerHD servos (servo spec link is: https://www.pololu.com/product/1056), and the Sparkfun connection guide for this particular project. It works great when I run one servo but when I try connecting two or three it doesn’t seem like there’s enough power and nothing works. I tried a 16V wall plug into the 7-15V input and still nothing runs. One servo wired by itself works fine but when I wire in two or three it doesn’t work. At three, the green LED power light really dims.

Just curious if anything jumps out to you or if there’s another way to wire the arduino to power each one of them in a different configuration so they all work or if I need to buy something else from you to connect them and make them work.

Thanks for any insight,

–Brian Thomas

[n1ist]

The 5v regulator on the Arduino doesn’t provide enough current to drive the servos. The best way to deal with this is to get a 5v power supply (such as https://www.sparkfun.com/products/15352 or https://www.sparkfun.com/products/15664) and use it to power the servos. Make sure the ground of that supply is connected to the ground of the Arduino as well as the servos. You can use it to power the Arduino as well by feeding it into the +5 pin