Member Since: August 19, 2008

Country: United States

  • … or for a more elegant filter solution you could mount two polarized filters, one fixed and one rotating. The filters would span from near transparent when aligned to opaque when at right angles.

  • … and so if your goal is to hack this for tracking motion at a distance, you would first want to provide optics to focus the image on a plane in front of the sensor (having the ability to do frame dumps would be very handing in setting up the optics).

    Once you have the optics how you want them, you could emulate the shutter feature by mounting a circular grayscale smoke filter ahead of the optics on a stepper motor or servo, then use the LED output signal to rotate the filter accordingly.

  • My take on the datasheet explanation is that the shutter feature modulates current (or PWM?) to the LED driver in order to scale illumination to keep the pixels somewhere centered between the highest and lowest values. This would ensure the greatest amount of usable image regardless of whether the mouse were on a bright white surface or a black surface.

  • Also… it took some searching to locate these cables. Why on earth are they not listed under the “Cables” heading??

  • It is simple to convert these to a servo extension cable- I use them all the time. Just snip off a three-pin section of 0.10" straight breakaway header and plug it into one side to make it a male. For better pin engagement, push the header pins through the plastic base until the length is equal on both sides. For a really secure connection a small piece of electrical tape wrapped around the finished connection keeps everything in place. I prefer to stock only female-female extensions because I use them the most. When I do need male-female, I just use this method.

  • I am going to use these to replace the homebuilt Picaxe programmer breakout I built. For mine I simply added the two resistors the Picaxe uses on its Serin pin. The original was built on stripboard; but this will make for a cleaner adaptor once I add two SMD resistors to it- should be simple enough.

    I find myself prototyping Picaxe projects on breadboard from time to time, and I found that such an adaptor really speeds up the process (I have never fully understood why the resistors are not simply built into the Picaxe’s, since they are necessary for proper operation and programming.)

    It would be cool if Sparkfun added the two resistors to this breakout and offered it as a Picaxe programming breakout, but I do not know if there would be much demand for it.

  • My guess is that they wanted to follow the now somewhat conventional footprint/pinout that the 24-pin Basic Stamp2’s use. Particularly, pins 21 through 24 have the same functions, providing the same necessary power supply, ground, Vout, and reset lines the Basic Stamp2 uses. I also noticed the new 24-Pin version of Parallax’s Propeller microcontroller uses the same pinout.

    The programming connections are different, but that is to be expected in this case.

    I have several older BS2-based projects that I am considering reworking and “supercharging” with this new Arduino board. The hardware compatibility will allow me to resurrect some of those older projects and try some things that the BS2 is simply to slow to handle.


  • Great video Pete. Honestly it covered much of what I already figured out, only you condensed into a few minutes what I learned by trial and error over about 20 years. Having never been “formally” trained in the subject, it is good to have some confirmation that I am on the right track. I started home brewing my own PCB’s, first with a Sharpie and photo-etch, then to printed transparencies, and finally on to Eagle and some of the low-volume quick turnaround fab houses, along with the great tutorials Sparkfun has provided.

    I would recommend this to anyone who is just getting started with PCB design. Eagle has lots of great tools to assist, but they don’t provide the common-sense methodology of the layout as you have done. Thanks for another excellent resource. -Rob

  • I think these modules are what I need. I have several remote valves and other equipment spread over an eighty acre property. I would like a central microcontroller to be able to switch valves on and off and maybe monitor pressure or valve postion- not a lot of data to pass, each location would have its own microcontroller paired to the XBee. I want the XBees in the network to need as little configuration as possible (or none)- moslty to simply emulate an RS-485 connection. If I powered on three of these within range of one another and I transmitted data from one, would the others all see the same thing? If two of the modules attempt to transmit back to the host simulataneously, is bus contention an issue or do they automatically handle that? If the modules are strung out over a distance and the host transmits to the closest one, will the outlying modules automatically retransmit the signal to the further out modules? I read through the manual and there is a great deal of information about programming and configuration. I wonder if I could do what I need to with these modules in the default mode, considering that if all locations are receiving the same information I could handle device addressing and ID through the individual microcontrollers.

  • I have been trying to use this as an isolation transformer to connect the audio from a toy robot to a Class-D amp line input (To be able to amplify the robot sounds to a much higher volume).

    It sounds great, but I just had my second audio synth board on the robot fail. Each time it worked fine until suddenly dying. Now that I think about it I wounder if it is not an appropriate use for this transformer. If the little toy audio circuit was intended to drive an 8-Ohm voice coil and now it is driving a 600Ohm winding, could that have overloaded and damaged the audio driver?

    I have since found an alternative bridge circuit that uses a simple 10:1 voltage divider to feed the amp input a voltage closer to what it is designed for. Could this be a better solution?

    Any help is much appreciated.


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