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How to power PINK module — Parallax Forums

How to power PINK module

lljc00lljc00 Posts: 3
edited 2007-11-11 16:12 in General Discussion
I'm new, so sorry for such a basic question.· How would you hook up and power the PINK module to a development board?· I have a Homework board (not tied to it, can move to something else like BOE if needed), and it says in the manual that the I/O pins provide 20 mA, while the PINK module says it needs 350 mA.· I dont want to damage my board before I even get a chance to play with it!·
Thanks!

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2007-11-10 19:09
    It's true that the I/O pins can only provide 20mA, but that is not true of the power supply which can provide roughly 500mA. You'll need to use something other than a 9V battery though because it'll run down quickly with a 400mA drain. You can find AC adapters with a 9V battery clip output, but you'll need to use one with enough current output (maybe 500mA) and a lower voltage than 9V (maybe 7.5 V) to minimize the amount of heat the regulator will have to dissipate ((input voltage - 5V) x 400mA = all heat!). The PINK power supply input has to be connected to the Homework Board's 5V power supply (Vdd) and, of course, the grounds (Vss) have to be connected together.
  • RDL2004RDL2004 Posts: 2,554
    edited 2007-11-10 20:23
    The PINK needs 250+ mA just idling and considerably more if actually doing something, this is pushing it on any of the Parallax boards,. It will work but don't be surprised at how hot the regulator gets. The PINK really needs its own separate power supply.

    I got this one off eBay for about $15 (including shipping), but it's pretty versatile. I just stripped the leads on an old wall wart and connected it to the power supply board (it can use AC or DC).

    attachment.php?attachmentid=49996

    Also, it might be useful to know that the J8 connector on the PINK / NetBurner board is an auxiliary/extra power connector (this is not in the Parallax documentation). You can power the board with 5 volts there (must be regulated), just make sure you have a common ground with your Basic Stamp. The pin out is :

    (+) +5 Volts <-Must be regulated!
    (-) GND
    (+) +5 Volts <-Must be regulated!

    Either or both +5 volt connections will work, this layout just makes it harder to connect with reverse polarity.

    This is how the PINK in the picture is powered. Be very careful about polarity, you don't want to blow up your PINK, and it needs to be regulated 5 volts! No wall wart or AC adapter here! Unless regulated!.

    For a while my PINK will be running here:


    75.65.162.169

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    - Rick
  • lljc00lljc00 Posts: 3
    edited 2007-11-11 00:08
    Thanks for the info. I bought an ac adapter that has selectable voltages from 1.5 to 12 V. Its only rated up to 300 mA, so hopefully that will be ok. BTW, i found a pic of a sample circuit between the BOE and the PINK module online - the older version of the doc (1.2) has it, but they've seemed to have taken it out of the most current doc (2.0). Wish me luck!
  • lljc00lljc00 Posts: 3
    edited 2007-11-11 00:30
    One thing on the AC Adaptor - it has a switchable polarity. It came set to the positive setting (i think its the positive, because its pointing to the symbole with the plus sign). Is this the correct setting?
  • RDL2004RDL2004 Posts: 2,554
    edited 2007-11-11 00:39
    Man, be careful. Wall wart/plug packs are all over the place on voltage output - some are not even DC. Run it through the Homework board first at least. You'll get 5 volts out and it will just shut down if too much current is pulled - nothing will blow up.





    Edit: You want center positive on a 2.1mm plug for most Parallax products

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    - Rick

    Post Edited (RDL2004) : 11/11/2007 12:10:07 PM GMT
  • DgswanerDgswaner Posts: 795
    edited 2007-11-11 02:51
    If you would like I can provide you with a PCB layout and parts list for a 5V power supply perfect for the pink, and it only measures 1/2"x2" I've been using one for my pink for weeks. all of the parts cost about $5.00 and actually if you want one I'll sell you for cost +shipping. or you could Google "LM2805 power supply" and find lots of info on them.

    PM me if I can help.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    A complex design is the sign of an inferior designer. - Jamie Hyneman, Myth Buster
  • RDL2004RDL2004 Posts: 2,554
    edited 2007-11-11 11:52
    LM7805?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    - Rick
  • DgswanerDgswaner Posts: 795
    edited 2007-11-11 16:12
    oops... yes LM7805.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    A complex design is the sign of an inferior designer. - Jamie Hyneman, Myth Buster
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