Choosing right hardware

Lynxmotion Robot Arms
1

Hi

I am quite new to robotics and started my studies in robotics like 3 months ago.

I bought the robot arm in the link below, I want to get rid of the Wired controller and install a micro controller to program and move the joints/ grippers.

Its has 4 motors installed, and uses 4 x D batteries to operate

robotshop.com/en/owi-535-robotic-arm-edge.html

Few questions:

  1. what type of micro controller would be suitable for this purpose? can you give me specific model?
  2. what other hardware i need to purchase along with the microcontroller?
  3. Each revolute joint shouldve an angle sensor too? in order to be able to have percise move?

Thanks

2

A microcontroller cannot be used to control the motors directly. You need to have a DC motor controller. A few microcontrollers come with a dual motor controller onboard, though most do not. You’re best off with a normal microcontroller connected to four single or two dual DC motor controllers.
robotshop.com/en/microcontrollers.html
robotshop.com/en/brushed-mot … llers.html
NOTE: The OWI-535 edge does not have positioning - you can only control the speed and direction of the motors. This means you cannot tell it to move to a specific angle, nor would it “know” what position it started in (i.e. relative motion only). This arm is not very suitable for use with a microcontroller since there is a lot which needs to be modified physically.

It depends what you want to do. You need the motor controller listed above, but unless you heavily modify the arm, it’s really not meant to allow you to control the angle of each joint.

Correct. Currently each joint does not have any sensor which provide the angle, and the mechanics are not great for adding one.

As you indicate, you are new to robotics. Hacking this arm is not easy. You would be better off simply purchasing a different arm such as:
robotshop.com/en/robotic-arm … -blue.html
robotshop.com/en/robotic-arm … duino.html

3

Hi Coleman

Thanks for the details reply.

I think, at this stage, I will be totally happy if I can move the joints (and eventually the arm) even randomly using the micro controller and DC motor controllers … Totally understand the randomness of the moves.

so for this purpose, as far as i get I need a micro controller and motor controllers to control 4 x DC motors?

Since this is the first time I am trying to make this happen, could please introduce the exact product suitable, form the online store?

  1. micro controller: which one of the models available i should buy
  2. motor controllers, same questions.
  3. anything else required.

Thanks a lot
Cyrus

4

We don’t have any stats on the actual current draw from each motor on the 5345 edge, so we’ll have to assume based on their size that it’s not too high. There are many ways to control up to five motors, so these are just some quick examples.

3x robotshop.com/en/seeedstudio … river.html
robotshop.com/en/i-o-grove-b … duino.html (to more easily connect the motor controllers)
robotshop.com/en/arduino-uno … oller.html (any shield compatible Arduino microcontroller)

In addition to these, you’ll need the wiring, USB cable and power. We do not have an exact list of products to make this project happen, nor any procedures - this is considered “hacking” hardware, and as such you’ll need to read through instruction manuals, learn how to program, make electrical connections etc.