Boilersrock

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.   Below is a

Simple non-inverting 3.3v output to 5V When the input signal is high, the transistor is effectively off, so the output is fed 5V  via resistor R2. When the input signal is low, the transistor conducts, pulling the output low as well.

GarageBox After a year long hiatus, I've begun to finish my Olimex ESP8266DEV based project so that I can control my garage door and also a set of Christmas lights via WiFi.  Below is the current state of construction. The large orange board on the left is an Olimex-ESP3266EVB development board.  It is actually two boards in one:  If you look at the upper left , you'll notice a smaller PCB with is the actual ESP3266 wifi module.  It sits atop a larger board that provides power, a programming port and a single control relay.  The relay on this board is what I will use to open & close the garage door. In the lower right (black board) is a solid-state relay.  I plan to use this to control a string of lights hung above the garage door. In the upper right (green board) is a 5VDC power supply. Door Sensor Below is the sensor that checks whether or not the garage door is closed.  It is an infra-red proximity sensor with an open collector output (E18-D80NK). 

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.   Invert

This is the second version of my Remote Lightbox Controller (RLbC) made from parts from the controller from last year. This new version is cleaner and simpler. At the top is the power supply for the box.  It's complete overkill at 15VDC@30A, but heck it was only $24 off of ebay.  In the lower right is your typical XBee +shield on top of an Arduino Uno (Rev2).  To the lower left is a SainSmart 8 channel relay board whose logic-side components are powered by the little green 5VDC power supply.  Yes, I might've gone with a buck/boost convertor, but since I already had the 5VDC kit I used it.   Another view of the control box.  Here you can see the wiring that connects the output jacks to the channel relays.    Lid closed, lamp cables plugged in.  The lamp cables are 25+feet long with standard 1/4" mono plugs at each end. Test arrangement.  At this point, I'm able to transmit control signals wirelessly from my laptop to the RLbC

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.