#netduino Woot-Off Detector Works!

There always comes a time when you repeatedly smack your head against the wall trying to solve a problem, and the answer is so trivial that you want to poke yourself in the eye afterwards. In the previous post(s), I mentioned that I was only getting 1.7v out of digital Pin0. When using a multimeter on just the pin itself with no load, I discovered that I was getting a constant 3.3v. So just to play and debug further, I brought up the example “blink” app and modified it to send a signal to Pin0 along with the onboard LED. Again, I found that I was getting a constant 3.3v. Surely something was wrong – this should have been switching from high to low along with the LED. Yes, something was wrong – my code! Here’s what I had:

pEnable = new OutputPort(Cpu.Pin.GPIO_Pin0, false);

Yeah, so GPIO_Pin0 is not digital Pin0. Arrgh. The correct code should be (and is now checked in):

pEnable = new OutputPort(Pins.GPIO_PIN_D0, false);

And because of this, we can completely disregard my last post.  No transistor needed.  Dumb.  But awesome.

All updated code is up on Codeplex.  Pictures are up on Flickr.  Here’s the package tucked in an Altoids tin:

Woot.NETMF Package

Curiously strong...


In a week or so, I’ll try to post a video of it in action and include a schematic and final parts list. With Thanksgiving this week, there’s a slim to none chance it will get done this week. Which is too bad, because with Black Friday, I’m sure there will be a Woot-Off or two.

This entry was posted in Netduino, Projects, woot-off detector and tagged , . Bookmark the permalink.

1 Response to #netduino Woot-Off Detector Works!

  1. Lyra says:

    I had exactly the same problem. It cost me a whole day to figure out, that Cpu.Pin.GPIO_Pin0 and Pins.GPIO_PIN_D0 aren’t the same.

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