I’ve purchased on of the MeArm robot arms and am wondering whether it’s OK to run all 4 servos using a 5 volt breadboard power supply. The power supply specs say it only delivers 700mA max and the instructions talk about the 4 servos needing 5v 2amp. If the breadboard power supply isn’t an option, what should I use (I’d prefer to use a power supply instead of batteries.
Thanks!
Small servos actually tend to consume more than standard sized in order to provide decent torque.
You’ll likely need a more powerful power supply (5V, 2A+). Note that most RC servos operate best at 6V:
robotshop.com/en/5vdc-wall-adapters.html
robotshop.com/en/6vdc-wall-adapters.html
I imagine this is a total noobie question, but how do I connect a power supply like this to my breadboard? Do I need a breadboard-friendly barrel-type input?
For breadboards (keeping in mind that they normally cannot handle high curent), you would need something like these if you want regulated output.
robotshop.com/en/breadboard- … odule.html
robotshop.com/en/dfrobot-bre … y-kit.html
robotshop.com/en/breadboard- … y-kit.html
If you want the voltage to go directly to the rails, then this would work (with two wires):
robotshop.com/en/barrel-jack … t0151.html
This is very helpful! Two hopefully last questions: both the breadboard power supplies you suggest don’t deliver 2 amps, which would make them inappropriate for driving the 4 servos, correct? Is 5v 2 amp too much to be putting into a breadboard? (the meArm instructions suggest that all 4 motors can be run off a breadboard.
thanks!
Question - why would you be using a breadboard for the connections? How do you plan to control the arm? There are easy ways…
I’m assuming you’re referring to moving to pcbs. We’ve got other stuff going on and have held off on hard-wiring anything until we get all the parts interacting properly. If there are easier (better) ways to do it that will still leave us the flexibility to rearrange connections without de-soldering, I’d love to hear about them (like I said, I’m a total noob at this.)
How do you want to control the arm? From a computer? Microcontroller? Joystick?
microcontroller (arduino Uno) The ultimate plan is to do it wirelessly using TouchOSC on an iPhone via an esp8266 chip.
Thanks for your patience BTW!
This will save you a lot of wiring:
robotshop.com/en/io-expansio … no-v6.html
robotshop.com/en/io-expansio … duino.html
OK, now I’m getting really confused. If I buy one of these shields, do I still need to provide external power to the servos? Also, the descriptions of the shield say that they have an exBee module connector, which I’m assuming means that I have to go out and buy an exBee module. Finally, having gone through all sorts of agony to figure out how to program the ESP8266 through the Arduino, will I have to go through the same process to program the ExBee in order to receive and translate OSC messages?
Yes, you would still need to provide 6V power to the shield, which in turn powers the servos. It saves you from having to use a breadboard.
You still need to program the Arduino to move the servos (Arduino servo library will help) and communicate with the XBee module (serial input / output).
Do I need to program the XBee as well? (as you probably know, the ESP8266 has only a small set of AT commands loaded to start with. Communication with the Arduino requires programming the chip.)
The XBee itself should not need to be programmed - plug it into the shield and simply use serial in and serial out.
