Author Topic: adding a motor driver to $50 robot  (Read 2280 times)

0 Members and 1 Guest are viewing this topic.

Offline RUBEN;bluesTopic starter

  • Beginner
  • *
  • Posts: 4
  • Helpful? 0
adding a motor driver to $50 robot
« on: July 14, 2008, 06:16:55 AM »
hi im new to robotics and  i was wondering if i could add a motor driver to the $50 robots existing circuitry so i could run motors instead of the conventional servos and if so how?
the motor driver i have in mind is one of a previous project i had named "cybot" it was part of the RealRobots series magazine where you received parts and a magazine every fortnight and seeing as i never quite finished it im trying to salvage bits and pieces of it one being the motor driver all this is for an assignment
any help would be great guys cheers!

Offline bulkhead

  • Full Member
  • ***
  • Posts: 102
  • Helpful? 0
Re: adding a motor driver to $50 robot
« Reply #1 on: July 16, 2008, 12:49:32 AM »
Electronic Speed Controls (ESC's) used in hobby remote control (RC) cars are often used to control 540 size motors, costing between $40-$100.  They accept the same PWM signal that's used to control servos.  You should be able to replace the continuous rotation servo with this and simply adjust some constants in the code to account for a different neutral, full forward, and full reverse pulse widths. 

A cheaper and more DIY solution would be to get H-bridges (try L293D, ~$2) and gear motors (~$8 solarbotics ones) to effectively create your own "continous rotation servo".  This would require some change in the code (no more PWM to control motors, must generate H-bridge signals instead).

Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,663
  • Helpful? 169
    • Society of Robots
Re: adding a motor driver to $50 robot
« Reply #2 on: July 25, 2008, 09:20:56 PM »
Got a spec sheet or schematic of your motor driver?

If you want simplicity tho, I'd just go with the servos. You'll end up buying servos anyway, if you plan to make robots in the future.

Offline RUBEN;bluesTopic starter

  • Beginner
  • *
  • Posts: 4
  • Helpful? 0
Re: adding a motor driver to $50 robot
« Reply #3 on: August 03, 2008, 12:01:53 AM »
Got a spec sheet or schematic of your motor driver?

If you want simplicity tho, I'd just go with the servos. You'll end up buying servos anyway, if you plan to make robots in the future.

yeah i got schematic sheet ill upload it now.
yeah i figured but i want to add a little bit of personal touches to the $50 robot haha,
 i actually do have some servos but i rather just use dc morors instead.

Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,663
  • Helpful? 169
    • Society of Robots
Re: adding a motor driver to $50 robot
« Reply #4 on: August 03, 2008, 09:18:46 AM »
This is a dual motor driver and will do the job.

But the servo code in the $50 Robot won't work for it. You will have to either use PWM (see timerx8.c/.h and the timer demo in AVRlib), or just call the motor pins high/low to control the motors.

Offline RUBEN;bluesTopic starter

  • Beginner
  • *
  • Posts: 4
  • Helpful? 0
Re: adding a motor driver to $50 robot
« Reply #5 on: August 04, 2008, 02:39:57 AM »
good stuff, so basically what ill have to do is change abit of the code around so that it recognizes the pins as high/low for each motor which will in turn decide which way the robot is going to turn.

 


Get Your Ad Here