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P8X32A Quickstart board power supply without USB? — Parallax Forums

P8X32A Quickstart board power supply without USB?

garyggaryg Posts: 420
edited 2013-03-12 14:26 in General Discussion
I had started a thread awhile back concerning learning about the Propeller.
I keep going back to the various threads, see some of the difficulties people are having and
I still feel the need to use a Prop on my currently in process platform project.
I'm convinced that the Propeller is the future.
Today, I went to my local Radio Shack store and looked at their Quickstart Board.
Cost was about $18 more than directly through Parallax, but it did include a cable.

I noticed that there is no power supply available without using the USB connection.

I have very basic needs, but my needs cannot be tied only to a USB cable.

What do people do to connect a Quickstart Board to a battery or other mobile power supply.

I realize this should have a simple solution, I just don't know what options are available.

I've been looking at this for a couple of months, and almost made a purchase, even at elevated cost, but I got over it.

Thanks for any suggestions,

Garyg

Comments

  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2013-03-08 20:01
    It'll get it's power from the computer it is plugged into when programming it.

    You can also add a jumper to /USB POWER ENABLE so that you can also power the board using a USB power supply. Some addon boards include this as an optional jumper, but you can also do it easily yourself.

    Here's some details and a picture.

    http://www.instructables.com/id/How-to-build-the-QuickPlayer-Extreme/step8/Special-page-for-DIYers/

    Jeff
  • Mike GreenMike Green Posts: 23,101
    edited 2013-03-08 20:06
    On the connector, there's a signal called Vin which is right next to the ground (Vss) pin. Vin is the input to the 3.3V voltage regulator and is the point where you should supply power. There's a diode in the USB power circuitry to prevent Vin from going back through the USB circuitry. You may want to put a diode in the lead from your power source to Vin so, if you try to program the QuickStart board's Propeller and have the external power source on, there won't be a conflict if the USB voltage is higher than your power supply's. Look at the QuickStart schematic for details.

    Assuming you have a diode in the external power (Vin) lead, your power supply should provide a voltage greater than 4V and less than maybe 9V (depending on the amount of current drawn from the 3.3V regulator ... heat issues).
  • garyggaryg Posts: 420
    edited 2013-03-08 21:48
    It appears to me, that Mike and Jeff are talking about Two different Quickstart Boards.
    The P8X32A that is shown in the Instructables link is different from the one that Mike is talking about.
    Also, The P8X32A that I was looking at in my local Radio Shack store appears to be the same one
    that Jeff has the link to in the Instructables.

    I'm thinking that the jist of this discussion so far is that there is really no straightforward way of using the P2X32A without the
    USB cable connecting it to my computer.

    My plan for now will be this:
    Locate a drawing for the P8X32A from the Parallax website or elsewhere.
    Discover the pinout of the USB connection and find out what is powering the P8x32A product.
    Fabricate a battery and plug that will connect into the P8X32A.
    Plug in the battery to the P8X32A and maybe Life Will Be Good.

    I will definitely look at the QuickStart schematic for the details concerning Vin location.

    I always look at the cost of building my small projects in that projects always cost about 10X what I'm expecting.

    Thanks for your comments so far.
    I may reconsider and keep sticking with my Basic Stamps.
    But I will look into this further.
  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2013-03-08 22:08
    @garyg,

    If it helps, the Quickstart sold by Propellerpowered comes with the ProtoLite board which can be powered both by USB (Power Enable Jumper) and by connection to screw terminals.

    This may help you lower the costs of your projects a little bit more.

    http://propellerpowered.us/index.php?route=product/product&path=25_61&product_id=52

    Jeff
  • mindrobotsmindrobots Posts: 6,506
    edited 2013-03-08 22:15
    Nope. Same board, there are just several ways to power it.

    Jeff's method is if you want to plug a USB power supply (wall wart with USB mini-B on the end of the cable) of some sort into the USB port and power it that way.

    Mike's method works if you want to plug the black wire from a battery pack into VSS and the red wire into VIN.

    You can also solder a pair of male pins into the holes marked VSS/VIN just off the end of the header and then put a pair of female connectors on your battery pack.

    If there is the potential for the voltage differences between your power source and the USB, then the diodes is a good idea.

    Jeff and Mike both know what they are talking about.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2013-03-08 23:43
    I usually add a pair of male headers to holes #39 and #40 to use as a power connection.

    Here's a picture that kind of shows what I'm talking about.

    attachment.php?attachmentid=83296&d=1311402017

    For a while after the QuickStart came out, I tried to collect links about the board and posted the links to this thread. I also added posts about some of my own QuickStart projects to the thread.

    There are some additional photos in that thread that you might find helpful.

    Jeff and I recently posted threads about using the QuickStart as the controller to an inexpensive robot.

    Here's a picture of my version of CheapBot.

    attachment.php?attachmentid=99098&d=1360188194



    Besides the pair of male headers for the power connection, I also populate the four Vss and four Vdd positions on the right side of the board with female headers.

    These added headers and the label, make the QuickStart much more user friendly IMO. The labels make a big difference when I'm adding a wire to a specific pin. It's much easier to read the label than trying to count holes.

    If you send me a PM with your address, I'll send you a couple of these labels. Phil also made some labels that look really nice. He was giving away his labels for a while but I don't think he's still giving them away.

    I've attached the file (in the QuickStart thread) for printing the labels in case you happen to have a Brother label maker (it needs to be one that can interface with the PC).

    I hope you give the QuickStart another try before giving up on it. The Propeller make projects possible that are way beyond the possibilities of the Basic Stamp.
  • 4x5n4x5n Posts: 745
    edited 2013-03-09 12:18
    When I got my first quickstart boards the came with headers soldered on them and a 9V battery connector. I'm not near the boards so I can't take a picture. I'll post pictures when I get home later today.
  • prof_brainoprof_braino Posts: 4,313
    edited 2013-03-11 09:42
    4x5n wrote: »
    When I got my first quickstart boards the came with headers soldered on them and a 9V battery connector. I'm not near the boards so I can't take a picture. I'll post pictures when I get home later today.

    Where did you get them? I never heard of them coming stock with 9v battery connectors...
  • softconsoftcon Posts: 217
    edited 2013-03-12 14:13
    My quickstart board also had pins for a 9-volt battery connector. I bought both of my quickstarts in the fm radio kit Parallax was selling some time ago, so I had a 9-volt battery plug that came with the kit. For a while, the plug was available as an extra, but I'm not seeing it in the store anymore. I'd wager though, that if you called Parallax, they'd be happy to provide you with one. If I recall correctly, they sold for $1.99 when they were in the store. Alternatively, Radio shack sells 9-volt battery connectors in bags of 5, though theirs don't have the jumper-like ends, just bare wires for connnecting, but you can likely rig something that'll work.
  • garyggaryg Posts: 420
    edited 2013-03-12 14:26
    Thanks for all of your comments and suggestions.
    I have ordered a P8X32A.
    It appears to be a good place to start learning how to use the Propeller.
    All of your comments have answered my Propeller Beginner questions.
  • gelfling6gelfling6 Posts: 60
    Resurrecting an old thread here.. I've gone as far as to power my Quickstart directly through the VDD & VSS pins on mine as well, using a Sony LIP-1359 batte4ry back from a scavenged PS3 controller, (3.7V output, the .04 higher voltage doesn't seem to affect anything.) I usually will plug a 5V USB charger and put the propeller into a small 'rest' program that stops at the end, in RAM, allow the battery to charge a little off the USB cable to the computer, then unplug the computer, and connect the charger. Otherwise, two simple IDC pins plugged into the batter connector, then plugged into the socket. (Yes, I added a 2X4 socket set top those empty pins too.) the last pin of the main IDC socket, 40, is +4V to +9V unregulated input, Gated from the +V pin of the USB socket by a JFET (3-pin SMT transistor above the 'Brownout" label), going to the 17-33 regulator directly above the USB. (so, if anyone gets the bright idea of plugging a >5V source into those pins while it's connected to their computer, DON'T! It could fry the USB host chip in the computer! Even if Pin 38 (USB_PWR_EN) is pulled high (JFET Off).)
    100_6882a.jpg
    640 x 480 - 106K
  • Duane DegnDuane Degn Posts: 10,588
    gelfling6 wrote: »
    I've gone as far as to power my Quickstart directly through the VDD & VSS pins on mine as well, using a Sony LIP-1359 batte4ry back from a scavenged PS3 controller, (3.7V output, the .04 higher voltage doesn't seem to affect anything.)

    I'm guessing your battery is a Lithium Ion battery? While the "nominal" voltage is listed as 3.7V, a freshly charged Li-Ion cell can have a voltage of over 4.2V.

    The Propeller's datasheets lists the supply voltage range as 2.7V to 3.6V. The "Absolute Maximum Rating" for Vdd is listed as 4.0V. I strongly suggest you stop using a Li-Ion cell to power the Propeller without a regulator.

    You may be able to power the QuickStart with pins 39 and 40 of the main header with your battery. When the cell is freshly charged, it will be above the 4V limit. I'm not positive but I think voltages less than 4.0V will work, but the output from the 3.3V regulator will likely be lower than 3.3V.

    I think using a Li-Ion cell to power the QuickStart from pins 39 and 40 is a much safer than powering the QuickStart with a Li-Ion cell directly to Vdd and Vss.

  • gelfling6gelfling6 Posts: 60
    Duane Degn wrote: »
    I'm guessing your battery is a Lithium Ion battery? While the "nominal" voltage is listed as 3.7V, a freshly charged Li-Ion cell can have a voltage of over 4.2V.

    The Propeller's datasheets lists the supply voltage range as 2.7V to 3.6V. The "Absolute Maximum Rating" for Vdd is listed as 4.0V. I strongly suggest you stop using a Li-Ion cell to power the Propeller without a regulator.

    You may be able to power the QuickStart with pins 39 and 40 of the main header with your battery. When the cell is freshly charged, it will be above the 4V limit. I'm not positive but I think voltages less than 4.0V will work, but the output from the 3.3V regulator will likely be lower than 3.3V.

    I think using a Li-Ion cell to power the QuickStart from pins 39 and 40 is a much safer than powering the QuickStart with a Li-Ion cell directly to Vdd and Vss.

    It is the Lithium-Ion, but will hardly ever get above, as I'm also using the on-board regulator as the limit on the charge voltage. The battery itself says a Maximum charge voltage of 4.2V, but I am charging it through the 17-33 regulator.. (barely trickle charge) just pulled the battery after charging through the regulator, and I'm reading only 3.31 absolute tops.
  • Buck RogersBuck Rogers Posts: 2,185
    Go ahead and laugh, but... What about the blue bodied battery packs that Best Buy was selling that we all scooped up? Perfect for the job.
  • RS_JimRS_Jim Posts: 1,764
    thread bump, need external power for quickstart.
    Jim
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