Shop OBEX P1 Docs P2 Docs Learn Events
Put a QuickStart board in standalone mode to run off USB charger? — Parallax Forums

Put a QuickStart board in standalone mode to run off USB charger?

mronmron Posts: 2
edited 2014-11-12 21:37 in Learn with BlocklyProp
Hi,
I'm new to these boards. I have a simple test program running on a QuickStart. It works only when connected to a computer via USB. If I power it up via a USB charger, the program fails to run. The supply voltage and current of the charger is 5V and 500mA. Is there a jumper or firmware switch I need to set?

Comments

  • Beau SchwabeBeau Schwabe Posts: 6,547
    edited 2014-11-05 17:19
    See this link :

    http://forums.parallax.com/showthread.php/135067-Serial-Quirk?p=1043169&viewfull=1#post1043169
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2014-11-05 17:43
    You need to reconfigure the FTDI chip in the QuickStart so that it does not need "permission" from an attached PC to power up. Here's an AppNote that should help:

    -Phil
  • mronmron Posts: 2
    edited 2014-11-05 18:17
    Got it! Thanks for the quick replies. I think I'll just try and use Vin. I'm on a mac and all the ftdi tools are PC. The FreeBSD version might work on the mac to reprogram the chip, but I don't want to risk bricking the QuickStart board.
  • GenetixGenetix Posts: 1,742
    edited 2014-11-06 09:31
    mron,

    What is the revision of your QuickStart Board, because on a Revision A board /UPE [USB Power Enable - Pin 30 on the QuickStart Header] needs to be externally pulled low by an external circuit to use a USB Power Supply.
  • prof_brainoprof_braino Posts: 4,313
    edited 2014-11-12 21:37
    mron wrote: »
    I think I'll just try and use Vin. ...... I don't want to risk bricking the QuickStart board.

    I found a USB power back I wish to use to power a quick start, but attached to the quickstart it reads 2.0v Vdd and 2.4 Vin. I see the same from a laptop which is not permitted to install the FTDI drivers. And this is because there is no PC to tell the FTDI chip to wake up correctly.

    So, have I got this right: Trim the end off an old USB cable, and use 5v and ground from the cable to Vin and ground on the prop quickstart. The D+
    and D- wires aren't connected to anything, but should be made so they don't short in case they are pluggedinto a regular USB port.This should power a stand alone quickstart.
Sign In or Register to comment.