Let's Make Robots!

OWI Robotic Arm with PIC-ready1 controller

This project is to replace the OWI Robotic Arm hand console with PIC based controller. The board used is PIC-ready1 board from mikroelektronika. this board has the USB interface, crystal and regulator with controller all in board for 29USD. see picture below.

PIC-Ready1 board

The robot arm uses DC motors with plastic gearboxes. however it is really cool and cheap arm. it is required to control all the 5 DC motors from the PC. in the PC VB or MATLAB maybe used as high level language to control the arm.



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It looks that you added the sensors to control the position of the motors.

Very good and smart work. I like it :)

you did not say any thing about the motors driving circuit.

I used L293D to drive the motors.  The L293Ds are driven from the uControllers (which are driven PC the PC (which are driven by the Post processor (which is driven by the GCode language))).


See http://www.zen21667.zen.co.uk/


I have completed my mod of the robot arm last night. My  mod uses Picaxes but that could be any uController is works very well and I have implements a pseudo CNC/PLC controller to give a really flexible language to control the robot.

Highlights are

  • Computer control of the Robot Arm in the 3 dimensions to 1mm.
  • Axis and Gripper control can be independent or any combination of axis(s) and the Gripper.
  • Computer control of the Robot Arm using the GCode language.
  • Manual control of the Robot Arm using the adapted controller (manual controller is now a digital controller). 
  • Gearbox mods that include a positional sensor and a opto movement counter.
  • All the mods use the standard motors and components.
  • Integration of the solution to Psuedo CNC controller via comms port.
  • Direct access to any axis via comms port.
  • Lots more... just need to document everything.




I got the OWI  USB interface. it is not a controller it is only driver for the motors. to make control we need to put some sensors and feedback controlling algorithm.


Any update on this project and how easy (or hard) it was to tap into the button controller?  Any pics of that?


if all motors need to be run at the same time , yes i should use 5 H-bridges.

It sounds like you are saying you can control all five motors from a single H-bridge, not simultaneously.  If so I'm curious what circuit you would use- a few relays or ?

it is good from driving point of view to use relay-multiplexer with one full-bridge. However, the relays are not always acceptable from response time, noise and speed of switching.

if replacing the relays with MOSFET switches would be really interesting circuit. 

Also, we can use one full bridge with four half bridges. the picture below clarify the connection.

It looks like five H-bridges are also necessary to control the arm.

The OWI already has a USB interface PCB that you can buy ready made, then hack if you want !


i have it and its working fine.

Unless of course you wish to do all that manually to increase your proficiency :)