One way to learn lots about a protocol is by implementing a bit banged version. Openschemes shares with us his experimentation with the Arduino and the FT232 chip.

"We’ve been considering the synchronous bit bang mode of the FT232R for an upcoming project. The first steps towards something like this are always to build up a little debug board or test bench that can be used for debug and tweaking while the real boards are in fab. Luckily for us, the Arduino board contains an FT232R ripe for the hacking. For most users, all their dreams are fufilled by avrdude-jtag, which will allow them to reprogram the bootloader on the Arduino Atmega. As you may know, four of the FT232R’s GPIO pins are brought out to an unpopulated header on the Arduino board. The first (and easiest) job is to solder in a set of header pins for future connections."

PJMonty from SoCalHalloween sure knows how to rig up some great animatronics! The bird and talking skull are funny and spooky at the same time! This project was entered in the Halloween Project Contest, which by the way there is still time to enter.

Via: HG Forum

"The electronics consist of two custom circuit boards I designed. The bottom one (most of which is obscured) contains the micro-controller and memory. It talks to the host PC via a serial port and has animation moves streamed to it on the fly. The top board has another micro-controller and is responsible for handling the time critical work of controlling the actual RC servos. It also has some interface circuitry on it for things like the LCD. Partially visible on the right is the power supply which powers both the circuitry and the servos."

SoCalHalloween - "Small Candy" from SoCalHalloween on Vimeo.

Piezoelectric elements can be used to make sound or detect sound. Steve Hoefer has made a Knock Lock, which is a device that can listen to knocks on the door. If the sequence of knocks is the same as the recorded knock sequence it unlocks the deadbolt on the door. Steve was the guy who also made the Dice Reading Machine.

Via: Zedomax

"While working on another project I ran across the Arduino knock sensor tutorial. Sensing a single knock is a great little project for learning about microcontrollers, but what about sensing specific knocks? Seeeeecret knocks? And if we could detect a secret knock, shouldn’t it unlock a door? If you can’t tell by looking this was cobbled together from spare stuff around the lab, it’s not much more than a piezo speaker, a tiny gear reduction motor, and an Arduino. And PVC pipe."

Ian from Dangerous Prototypes has made a high tech Multi Color Remote Controlled LED Pumpkin. It uses a remote control to change the inside glow color. Schematics and code are provided so you can make your own.

Via: HG Forum.

"It uses a minimal PIC 18F2550 circuit that decodes the remote control signals and drives a ShiftBrite color changing LED module. The F2550 is a USB PIC with a USB bootloader, so it’s technically a USB upgradable pumpkin too. The color changing LED is a ShiftBrite module from Macetech.com. It’s driven by three PIC pins and powered by a 5volt supply."

If you have a need for a DIY 30KV power supply have a look at this one that Daniel Eindhoven from megavolts.nl has built! You may have to scrounge for the parts for a few years though since it took 30 microwaves to get the needed parts. If you are thinking that you remember the name you are right, Daniel is also the one who brought us the MV CoilMaster Mark1 Coil Gun.

Kizomox has been working on some great high voltage experiments lately. You may remember the Potato that he Exploded with Defibrillator Capacitor that we featured before. Looks like he has moved way up in power since then! There aren’t very many people who have their personal pole transformer in their back yard.

Via Article comments.

Ever wonder how those cheap devices at Walmart sense you walking by so they can play the cricket sound or meow like a cat? Have a look at the circuit for these Spooky Halloween Eyes for some details. A slight change in ambient light is all it takes for the small device to "see" that someone is close.

"The schematic is quite simple, each of the devices (LED’s, phototransistor, sounder) are simply connected to the appropriate uC pin. The phototransistor is biased by a single 499kohm resistor. This seemed to give a nice range of resulting voltages in the low light levels expected during operation. Triggering is done using by detecting a change in illumination, not an absolute threshold, thus this should provide nice performance."