HI New Member!

Comments

• HShanko Posts: 402

  2011-09-11 14:47 edited 2011-09-11 14:47

  sam badwawulfs,
  
  Welcome to the Propeller forum. Sounds like an interesting project. Lots to learn; but isn't that the way 'LIFE' is?
  
  There will be many here to help you with various aspects of your design when you get bogged down.. Hardware, soft/firmware, all the other stuff to make it work.
  
  I suppose you are referring to your 'bigger version' as the 40-pin DIP packaged Prop 1. Fortunately the die inside the three packages is identical. That's where many of us started early after the Prop was released.
  
  Best wishes for loads of fun with the Propeller.
• Mike Green Posts: 23,101

  2011-09-11 15:20 edited 2011-09-11 15:20

  There are tutorials and Nuts and Volts columns here on using stepper motors with a Stamp. The principles are the same with a Propeller. Look at Nuts and Volts Column #6 for a start. Bipolar transistors are current dependent and work just as well with a 3.3V input from a Propeller as with a 5V input from a Stamp. The series base resistor has to be smaller with 3.3V to get the same amount of current through it. Use Ohm's Law. Look at the schematic and documentation for the Propeller Professional Development Board which includes a Darlington Transistor Array commonly used to drive small stepper motors.
• Cluso99 Posts: 18,069

  2011-09-11 18:45 edited 2011-09-11 18:45

  badwawulfs: Welcome to this fantastic forum.
  
  You might consider a stepper driver IC such as the Allegro A4982/3/4/8. They are easy to drive providing you only need 2A. Steppers are used in the RepRap (a 3D plastic printer) and you can find some info there www.reprap.org The propeller chip is a great chip for driving multiple arms because of the multiple cores.
  
  This should set you on your way. And don't be shy about asking questions... we are all here to help.
• RS_Jim Posts: 1,773

  2011-09-12 06:12 edited 2011-09-12 06:12

  Hi Sam

  badwawulfs wrote: »

  Hi, every one, im a new member and i would like to interduce my self. i have a Parallax Porpeller chip, One of the kits so its the bigger version not devlopers tiny sqare one.
  
  I have decided to take on the challange of building a 5 axis programable arm. I have some experance in programing so the SPIN code is very easy to understand. but my electronics are behind. i have read some books on electronicis so i know a little bit but thats coming along ok.
  
  Starting out on my goal of a 5-axis arm, I decided to make a switch using a transiter. i started out watching 5-axis arm videos on youtube then i looked up how transisters work, how to use a transiter as a switch..ect. i also got out my electronics 300 in one kit and the basic transister training. heres what i found.
  
  Im haveing problems understanding how to get the transister to not give any voltage untill the 3 volts are sent to the base wire on the transister.
  
  also im not sure how a transister is rated.. so i can get higher volts to run a stepper motor with out any volt going through untill the base is (i belive "charged" is the word..) and lets the electricty to power the stepper.
  
  and lastly when using transisters, stepper motors, and the propeller chip. are there any good guides i could get to learn how to do this? if not thats fine im sure ill get it soon.
  
  Thanks for reading, any help would be great!
  -sam

  In Obex there is a demo program for driving a unipolar step motor. This program runs in SPIN and at the least will drive a basic motor through a ULN-2008. This chip will allow you to drive two low current stepper motors without any additional hardware. See the stepper that Parallax sells. The driver does drive the motor FWD and REV. The code for the ramping is incorrect but the driver function works and you can test your motors with it.
  Jim
• badwawulfs Posts: 4

  2011-09-13 13:33 edited 2011-09-13 13:33

  ok great! thanks for the help!
  
  OK im wondering if i can use computer power supplies to power steppers.
  Also ill probly want to get a controller chip maybe the Allegro A4982/3/4/8 as recemended
  and what transisters should i get? i see in the BASIC stamp section 6 i belive they list 3 diffrent kinds but im wondering if there are any better ones to use.
  and what are some good high resolution stepper motors to get? im thinking im going to make the prototype a little lighter but if i could lift 5 pounds that would be great for now.
  
  thanks im really excited to get some real world 3D action going with the 5 axis arm!
• smbaker Posts: 164

  2011-09-13 14:04 edited 2011-09-13 14:04

  badwawulfs wrote: »

  OK im wondering if i can use computer power supplies to power steppers.

  
  Beware that some ATX power supplies need minimum loads on some of the pins to function properly. For example, sparkfun makes an ATX-to-binding-post breakout board (http://www.sparkfun.com/products/9774) and there are a lot of comments on it. I once considered buying one of these myself but went with a conventional lab supply instead.
  
  Also, in case you wanted to start with a lighter-duty robotic arm prototype, there is a nuts & volts article in the current issue that describes using the prop as an 8-axis servo controller. A company called lynxmotion makes servo arms, and erector sets of parts to build similar things, but it looks like they top out at about 1lb lift capacity with the largest servos.