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Pwm ic ? — Parallax Forums

Pwm ic ?

grasshoppergrasshopper Posts: 438
edited 2008-10-15 01:45 in General Discussion
I have been looking for an IC that I can integrate with the propeller to control a small motor or fan. I would love to be able to send it a value and then have it PWM the motor/fan. I would even settle for a constant voltage instead of PWM as long as the propeller could adjust the voltage with a value. Any ideas or suggestions?

Yea the propeller could do this in its own cog, but I am running all cogs (8) for more important things.

Total voltage is 5 - 2.7 and current is 200ma max [noparse]:)[/noparse]

Thanks in advance.

Comments

  • hippyhippy Posts: 1,981
    edited 2008-10-14 11:30
    Any small micro could do the job but you would still need the power-side interface. A cheap micro with a pre-programmed basic interpreter or similar would be quick and easy to use; read the required setting via serial, set the PWM duty.

    I've not done much with the counters on the Propeller but it may be worthwhile looking at those.
  • grasshoppergrasshopper Posts: 438
    edited 2008-10-14 11:56
    Thanks Hippy.

    I have considered a small cheap micro, but which one? I don't want to learn a new programming language and have to purchase expensive compilers etc. Hum any other ideas or direction towards a cheap small micro.

    Maybe I can get Parallax to make a small IC that has 4 I/O lines in a 8-soic package and runs spin...
  • Mike GreenMike Green Posts: 23,101
    edited 2008-10-14 13:29
    The ATTiny13 used in the BS2pe Motherboard is a small cheap micro that does PWM among other things. You have to talk to it using the 1-Wire protocol, but there's an object in the Object Exchange that does that. On Parallax's webpage for the Motherboard, there are links to the source code, a downloader, and the free development package. Have a look at it.
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2008-10-14 14:12
    You should look at the SX28 chips that Parallax has. There are numerous projects that have been created using these processors as intelligent slave devices for other processors. The project you are asking about has already been written for the SX28 chip using SX/B. I've used quite a few of the SX series chips for projects like this and they work out great!

    Robert
  • hippyhippy Posts: 1,981
    edited 2008-10-14 14:50
    Mike's solution looks good and ready-to-go. I'd choose a PICAXE because that's what I'm familiar with. Just five lines of source code like BS1 PBASIC, mainly; "SERIN pin,baud,var : PWMDUTY pin, var".
  • grasshoppergrasshopper Posts: 438
    edited 2008-10-15 01:45
    Thanks for the input fellas.

    Mike that Attiny13 looks like its gonna be a good choice.

    Again thanks all.
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