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Propeller Clock Powered by the Propeller Microcontroller — Parallax Forums

Propeller Clock Powered by the Propeller Microcontroller

Ray_DRay_D Posts: 8
edited 2014-04-18 11:03 in Robotics
Here is my entry to the "Hack the Halls!" contest. I started making this out for my brother and when I saw the contest I figured I'll post and see how I do. Check out the video:

http://www.youtube.com/watch?v=hSxGq68Pllk

It was supposed to be a simple project to help me get better with using the Propeller microcontroller but it turned out to be a great challenge. Here's a short summary of the components:
  1. A 555 timer generates an AC signal to a power MOSFET to deliver current through the primary coils of an air core transformer to get power to the rotating propeller.
  2. the secondary coil (attached to the rotating propeller) picks up the AC signal.
  3. The AC signal goes through some circuitry (see attached schematic) to get a 3.3V to power the components on the propeller.
  4. a 2nd 555 timer generates a ~38KHz signal to the IR LED
  5. an IR detector at the propeller picks up the IR signal for reference.
  6. a DS1302 was used to keep track of the time
It's programmed to display the clock except on Christmas day when it will read "Merry Christmas" in the bottom and my family's name's on the top for 30 seconds every minute (as shown in the video). This year will be my first year that I don't get to spend it with my family so when they see the clock I'll still be able to with them a Merry Christmas :-) On New Years it will say "Happy New Years" for 30 seconds every minute. On a regular day it will read "get better soon brother" at the beginning of each hour (my brother started taking dialysis this year so I wanted to make something to cheer him up).

Let me know what you think.



PropClock - Power PCB.jpg
PropClock - Prop PCB Back.jpg
PropClock - Prop PCB Front.jpg
PropClock.jpg

Comments

  • SRLMSRLM Posts: 5,045
    edited 2012-12-18 22:39
    Very impressive project! I'm interested in learning more about the air core transformer. I've always wondered how to get power to a rotating bar. Off to Google I go! Are you considering releasing the source code?

    To be elegible for the contest, don't forget to provide a link in the Hack The Halls thread: http://forums.parallax.com/showthread.php?144156-CONTEST-Hack-The-Halls!
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-12-18 23:05
    Ray_D,

    That's just too cool for words! Good luck with the contest and to your brother! I hope he has a full and complete recovery.

    -Phil
  • Martin_HMartin_H Posts: 4,051
    edited 2012-12-19 04:12
    Nice job! I like how you solved the problem of getting power onto the rotating Propeller board. That really keeps the rotational inertia low.
  • ercoerco Posts: 20,255
    edited 2012-12-19 19:41
    Amazing project, Ray! Nice way to stay in touch with your family over the holidays. Good luck to you in the contest and to your brother's health.
  • Ray_DRay_D Posts: 8
    edited 2012-12-19 22:49
    @SRLM, Oh yeah I forgot to include the code so here it is.

    Also, I didn't give credit to those that are due. I picked up some ideas from "Tjaco's design graveyard" where he has a schematic of a propeller clock he built. Also, thanks to Steve Augsberger who gave me some insignt on filtering out the AC signal being picked up by the secondary coil.
  • trannghia308trannghia308 Posts: 2
    edited 2014-04-17 08:48
    Hi! My name's Nghia, i see your project using wireless power to supply the power for MCU board. Could you tell me the diameter of the 30 gauge and 24 gauge when we do 500 turns and 100 turns. In my country we don't use the unit "gauge”, how can i change it to ”mm” ?Thanks so much!
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-04-17 10:01
    Nghia,

    I'm pretty sure the "gauge" in this case is the American Wire Gauge. You can find a conversion table in this Wikipedia article.
  • trannghia308trannghia308 Posts: 2
    edited 2014-04-17 17:33
    Hi Duane Degn!
    I know the convertion, but we'll get the inaccuracy. That mean maybe the Emitter and Receiver have different frequency and they can't work. Do you think so?
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-04-17 18:35
    Hi Duane Degn!
    I know the convertion, but we'll get the inaccuracy. That mean maybe the Emitter and Receiver have different frequency and they can't work. Do you think so?

    I hope others will correct me if I'm wrong but I don't think the gauge is very important. You just need to make sure the wire is large enough so the resistance isn't too high. I think the important figure is the number of turns used in the coil. I think if you use wire that's thicker than what Ray_D used, it shouldn't be a problem.
  • abecedarianabecedarian Posts: 312
    edited 2014-04-18 11:03
    Wire gauge is mostly related to how much current a wire can carry at some particular voltage without heating up so much that it negatively affects current or voltage, and doesn't burn up the insulation.

    If there is some inaccuracy converting AWG to MM wire sizes, choose the MM wire size that is larger than, but as close as possible to the AWG size.
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