Just Passing Through

Member Since: December 16, 2011

Country: United States

  • If you go to the data sheet for the photo-interrupter, they recommend putting a 103 capacitor across the power supply and the ground. Also read my post about my suspicion of the current limiting in the comments on the photo-interrupter device itself. You may need to add a transistor circuit on the output in order to drive things that need current like LEDs. If you hook it up without the the SparkFun board, make sure you pay attention to the ~47 ohm series resistor on the infrared LED that is shown in the datasheet for the device under the timing test. I think it might be built into the Sparkfun board, but not in the device itself. It sizzled one photo-interrupter when I forgot to include it.

  • I've always been fond of this one...


    The more you go... The more you go!!!

  • Every time someone suggests doing something stupid, it encourages some people to test the limits. Capacitors can kill you when charged. So the smart thing is always practice safe habits and then no one gets hurt. Kids in particular don't always practice safety.

  • Sparkfun should offer a few options to buy Makerbeam of various lengths. I found out that I go through a lot of the 10, 15, 20 and 30 mm in framing the project and have little use for the 4 and 6 cm beams. Also, the option to buy more 90 degree brackets and nuts & bolts would be helpful, too.

  • ... and then I'm going to post it on the internet. Click!

  • Unless you can afford to defend it (meaning lots of $ and productive time lost), then a patent is pretty much a useless effort, a money sink and a boat anchor to you and your business.

    If you have a big idea and a big company wants it, they will just use it. They know that typical defense costs when going against a big company can be in the millions. They retain big lawyers for big $ for precisely that reason. You cannot. You are not that rich. So if your idea is really good, you will go broke long before you ever get to court. And then the big company just uses it.

    If you have a little idea, then there will be the zerg-rush of copycats and again, you can't stop the zergs. You cannot undertake a hundred legal actions, the patent cannot be enforced.

    So the reality of the matter is, that a patent can only work for big companies in this day and age. the little guys - they just can't compete that way in the modern age.

  • I just got one of these and the black and red leads are swapped from the photo: the sensor I have has the black on the left and the red on the right. I hooked it up using the instructions on Bildr Tutorial and it stayed railed on 'motion detected'. So I took a shot and switched the black and the red leads (working off the 5V Arduino USB power). Still no change in response with motion/No motion. Replaced the 10K resistor with a 1K and then it was always railed the other way - no 'motion detected'. Added a 10K pot to the 1K resistor and got it to work somewhere in between 10K and 1K. Don't forget to put the 1K in series with the POT to make sure you keep the current sinking into the signal lead from becoming a short. Turns out with the sensor I got, the signal pin is red, the +5V Power pin is black and the ground pin is brown!