Shop OBEX P1 Docs P2 Docs Learn Events
Another example of a poorly designed battery powered propeller based product - Page 2 — Parallax Forums

Another example of a poorly designed battery powered propeller based product

2»

Comments

  • william chanwilliam chan Posts: 1,326
    edited 2009-01-23 02:28
    Different brand of aircon uses different protocols, so it is not so simple.
    On top of that, most aircons send mode, temperature, louver, timer and fan speed in one go when you press the ON button.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    www.fd.com.my
    www.mercedes.com.my
  • Ken PetersonKen Peterson Posts: 806
    edited 2009-01-23 03:30
    I think William is referring to actually digitizing the bit stream from a remote rather than storing the actual codes. This would allow it to learn from any remote, but would use a lot of memory.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

    - Bjarne Stroustrup
  • Ryan CrabbRyan Crabb Posts: 3
    edited 2009-01-23 05:59
    You have an excellent idea. I have no use for it as I have central air in my home. I was hoping to see another open source type product. I can understand completely not releasing any code or schematics. It does take alot time and money to develope a product. Just remember to give back to the propeller comunity. I'm sure you found some example code here usefull in your developement. Good luck and keep us posted on your progress.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2009-01-23 17:02
    William, very nice. I hope you find a cabinet that you like for your project. I know how difficult that can be to the extend I have built projects (and PCB) around a cabinet I already had.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Engineering
  • Timothy D. SwieterTimothy D. Swieter Posts: 1,613
    edited 2009-01-23 22:37
    William - great idea for the air con remote. This type of device could be useful here in Hong Kong since most home have an AC wall unit in each room. I understand your dilema about the PCB design and the case. It sounds like you might have an idea on what size you want, so keep searching and eventually the two paths will meet and you will be able to design a case and a PCB.

    So, the reason you can not use an SX is because of the ram size? The reason that ram size is large is because of learning of the IR pulse stream?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Timothy D. Swieter, E.I.
    www.brilldea.com - Prop Blade, LED Painter, RGB LEDs, uOLED-IOC, eProto for SunSPOT, BitScope
    www.tdswieter.com
  • RaymanRayman Posts: 14,662
    edited 2009-01-23 23:10
    Maybe these handheld plastic cases from Hammond would be about the right size for you:

    http://www.hammondmfg.com/1553colors.htm

    Sparkfun also has a clear plastic enclosure:

    http://www.sparkfun.com/commerce/product_info.php?products_id=8632

    I'm surprised you can run the Prop for so long with just 2 AAs!· But, maybe with no LEDs or display, it's possible...
  • william chanwilliam chan Posts: 1,326
    edited 2009-01-24 01:03
    Timothy D. Swieter said...

    So, the reason you can not use an SX is because of the ram size? The reason that ram size is large is because of learning of the IR pulse stream?

    Yes. That is my opinion, but I could be wrong.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    www.fd.com.my
    www.mercedes.com.my
  • william chanwilliam chan Posts: 1,326
    edited 2009-01-24 01:35
    Rayman,

    The blue casing looks nice.
    But some of the casing cost more than the propeller!, makes us realize the bargain the prop is.
    Rayman said...

    I'm surprised you can run the Prop for so long with just 2 AAs! But, maybe with no LEDs or display, it's possible...

    Like I said earlier, the Prop's battery capabilities are still a kind of secret to many.

    The first prototype PCB uses 800uA and it lasted 1 month.
    So I figured the current PCB which uses only 140uA should last 1 year.

    The LEDs blink 10ms every 1 second so it's current is negligible.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    www.fd.com.my
    www.mercedes.com.my
  • mparkmpark Posts: 1,305
    edited 2009-01-24 02:14
    800/140 = 5.7... How do you figure a 12x increase in battery life?
  • william chanwilliam chan Posts: 1,326
    edited 2009-01-24 02:48
    mpark said...
    800/140 = 5.7... How do you figure a 12x increase in battery life?

    The mantra is that the less current you use, the more the battery life increases, not linearly but exponentially.

    This board actually has a switching boost regulator underneath the Propeller.
    When using the boost regulator, the current consumption is 250uA. But the batteries can be used until 0.5v (sum voltage of both cells).
    When connected directly without the boost regulator, the current consumption is 140uA, but the batteries can be used only until 2.7v

    Which is better?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    www.fd.com.my
    www.mercedes.com.my
  • mparkmpark Posts: 1,305
    edited 2009-01-24 03:12
    william chan said...

    The mantra is that the less current you use, the more the battery life increases, not linearly but exponentially.

    Ah, makes sense. Thanks.
  • Ken PetersonKen Peterson Posts: 806
    edited 2009-01-24 15:44
    If RAM capacity is a concern, you can add an external serial RAM quite easily. Many microcontrollers have built-in support for SPI

    http://forums.parallax.com/showthread.php?p=778710

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ·"I have always wished that my computer would be as easy to use as my telephone.· My wish has come true.· I no longer know how to use my telephone."

    - Bjarne Stroustrup
  • william chanwilliam chan Posts: 1,326
    edited 2009-01-25 00:50
    I forgot to tell you that there are still some other difficulties presented by this project that only the propeller can handle.

    One is to be able to change it's own clock speed.
    To play or record the IR, I run the propeller at 40Mhz momentarily.
    After that, it runs at 20Khz to keep the RTC, blink some LEDs,
    verify the power status of the aircon( in case it is changed by humans using the aircon remote),
    detect humans moving around and countdown to switch off the aircon.
    The multitude of tasks required means that the Propeller is not allowed to sleep at any time.

    I am more familiar with the SX than the Propeller, but the SX can't do this.
    Can any Freescale change it's own clock speed?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    www.fd.com.my
    www.mercedes.com.my
  • mctriviamctrivia Posts: 3,772
    edited 2009-01-25 01:21
    the ti 420 day processer would draw less power and have smaller cost. i beleive it runs 20mhz all the time though except when asleep. but it can be woken by clock time so this meens you can artificially slow it down.
Sign In or Register to comment.