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Finally closed my Facebook account.  😿

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DorkTronic 10000

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Introducing the DorkTronic 10000 Dave & Meredith Suter have a new kind of display coming this Halloween and it's going to feature a bit more interactivity than in years past - the kids in the area are going to love it! To help pull this off I'm building the DorkTronic 10000. At the heart of the DT10K is a Raspberry Pi 3B (RPi), a credit-card sized computer that costs about $35.  It's about as powerful as an iPhone 6 or a Pentium 4 computer running Windows XP, making it more than capable of running all sections of the display.  Part of the interactivity will include telling a visitor their fortune or providing a damned good joke - and I know how much all of you love a good joke.  Prototype  The display will allow a visitor to start the show by either standing in front of a Sonic Sensor, or by pushing Big Button (which also flashes).  From there, the RPi will activate strobes, fog machines, a soundtrack with sound effects, and glowing eyes....
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RESET circuit

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One thing I had to add was a power-up RESET circuit, which is just a 10uF cap and 1K resistor in series across the 5v supply. The RESET pin on the counters are connected to where the resistor and cap meet so that at power up, the cap is effectively a short to 5+. This causes a logic HI on the RESET lines to set the counters to zero. After the capacitor has charged up, it no longer looks like a short to 5+, so the only path left is through the resistor back to ground. That presents a logic LOW on the RESET pin, which allows the counter to count up or down.
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Pboard

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Pboard  Project Pboard (short for "P-channel board") is the working nickname of a new driver board that I plan to use with the next version RLbC.  Whereas RLbC 2 only featured output relays, Pboard will make use of  Adafruit's PCA9853 based servo-driver board to provide PWM signals to the outputs via P-channel MOSFETS.  Doing so will allow for fading the lights. Why use P-channel Mosfets? I chose to use  FQP27P06 P-channel MOSFETS over the more commonly accepted easier to wire N-channel logic-level MOSFETS out there simply because I wanted high-side switching.  Call me weird or old-fashioned, but I have always designed my low-level voltage systems with Common tied to the "negative" side of a supply (split or dual-tap not withstanding). However, going to P-channel switching does make the design a little more complex. Buffering is required since I can not directly tie the output of a PCA9685 to Vss (12VDC) otherwise it will be damaged....
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