Hi, we have the inventors kits. The servo that is included with the kit has a really hard time working and almost no students get them to work. I am thinking it is a voltage issue as the rating on the servo motor (9g A0090) says 4.8-6 volts yet the micro:bit only supplies 3 volts.
What can I do to get better luck using these with students? Do I need a separate power source for the servo and just use the signal cable from the micro:bit? Can you give me a suggestion on what power sources to get that are easy for students to hook to the servo?
Thanks,
Andrew
Hi Andrew,
We have a few options that will probably work well for your students. If you want to stick with battery power, a 4xAA battery pack will give you 6V (with fully-charged batteries) to power the servo. We have two types that I think would be good fits, [this 4xAA holder just has bare wires coming out of it that you can plug into the breadboard to power the servo or if you want to use the jumper wires included in the kit, we have [this 4xAA holder that is terminated with a barrel jack connector that you can use [this adapter to break out the + and - terminals and then wire to your breadboard to power the servo. Just make sure that with both of these you isolate the power for the servo while maintaining a common ground between the servo power supply and the micro:bit. To do that, disconnect the red wire and keep the black wire in [this diagram connected to the ground plane for the servo and then connect the +/- wires to the servo’s power inputs.
If you want to use a wall adapter, [this 5V/2A Wall Adapter will work just fine. Again, you’ll want to use the barrel jack adapter I linked above to split out the +/- pins of the power supply while also maintaining a common ground connection between the power supply and the micro:bit.
I hope this helps you find the right power option for your students’ servos. If you have any follow-up questions about these or other SparkFun products, let me know and I would be happy to help.](Wall Adapter Power Supply - 5VDC, 2A (Barrel Jack) - TOL-15312 - SparkFun Electronics)](https://cdn.sparkfun.com/assets/learn_tutorials/5/2/4/Exp_08_bb2.jpg)](https://www.sparkfun.com/products/10288)](Battery Holder - 4xAA to Barrel Jack Connector - PRT-09835 - SparkFun Electronics)](Battery Holder 4xAA with Cover and Switch - PRT-12083 - SparkFun Electronics)
