Wherever you stand on the topics of road safety and vehicle speed limits it’s probably fair to say that speed cameras are not a universally popular sight on our roads. If you want a heated argument in the pub, throw that one into the mix.
But what if you live in a suburban street used as a so-called “rat run” through route, with drivers regularly flouting the speed limit by a significant margin. Suddenly the issue becomes one of personal safety, and all those arguments from the pub mean very little.
The theory of operation is straightforward, the software tracks moving objects along the road in the camera’s field of view, times their traversal, and calculates the resulting speed. The area of the image containing the road is defined by a bounding box, to stop spurious readings from birds or neighbours straying into view.
[Coyt] wanted a more convenient way to keep up to date with the ever-changing Bitcoin exchange rates, as well as weather and other useful information. He realized that the vacuum fluorescent display (VFD) he had purchased a couple of years ago would be perfect to display small amounts of information.
[Coyt] discovered that the VFD had a serial interface. The problem was that the VFD was looking for a 12V serial signal but the Raspberry Pi he wanted to use runs at a 3.3V. Upon closer inspection [Coyt] discovered that the VFD actually ran at lower levels as well, but it had a level converter chip installed in front of the main connector. He simply bypassed the level converter and was then able to get the RasPi speaking directly to the VFD.
The brain running this display is a Raspberry Pi. The Pi runs a Python script that pulls down all of the relevant information from the internet and displays it on the VFD. [Coyt] didn’t stop there, though. He knew that having the screen on all of the time would be somewhat of a waste, so he hooked up a PIR sensor to automatically turn on the display only when needed. The PIR sensor can detect motion in the room and will disable the display after a set period of inactivity. Most of this is powered by an LM7805 voltage regulator. While [Coyt] admits a linear regulator is not his ideal solution, it does get the job done. The metal stand acts as a nice heat sink for the regulator.
[Coyt] also wanted his project to have a certain aesthetic. He started by bending a metal plate into a stand for the electronics. He then mounted the VFD on the front of the stand and the RasPi on the back. He also mounted green LEDs between the two plates to light up the edges for a little extra pizzazz. [Coyt] believes he can use the RasPi to PWM the LEDs but this has not yet been implemented. This would allow him to pulse the light for added effect.
Since the whole thing is run by a Python script, it would be trivial to modify it to display other kinds of information. What would you do if you had a motion sensitive automatic ticker?
[Michael] just missed the deadline for the Trinket Contest but we still think his tablet is pretty cool. He says it predates the iPad and uses a custom aluminum case, a SoC he ripped from a Gecko Edubook, powered by eight NiMH batteries. Check out the front, the guts, and the sides.
Speaking of portable power sources, After doing a teardown of a 12V 6800 mAh Li-Po battery [Howard] strapped some prototyping equipment to either side of it and now he’s got a prototyping power supply that’s easy to take with him.
Blinky goodness doesn’t have to look hacked together (even if it is). This Raspberry Pi logo looks like a professional sign! It was cut from foam and plastic, primed and painted, then stuffed with addressable LED strips.
We’ve been saving the gnarliest link for last. [Matthew] laments that his missed Halloween to show off this project. But we don’t think an almost-entirely wooden spider-like walker needs to be paired with a holiday. It’s very cool and somewhat operational, but still needs help working out all of the kinks. Our favorite moment in the video is when [Matthew] exclaims “It wants to live!”.
For all their hoopla, the GPIO pins on the Raspberry Pi aren’t terribly useful on their own. Sure, you can output digital data, but our world is analog and there just isn’t any ADCs or DACs on these magical Raspi pins.
The AlaMode, a project designed by [Kevin], [Anool], and [Justin] over at the Wyolum OSHW collaborative aims to fix this. They developed a stackable Arduino-compatable board for the Raspberry Pi.
Right off the bat, the AlaMode plugs directly into the GPIO pins of the Raspberry Pi. From there, communication with the ATMega of the Arduino is enabled, allowing you to send and receive data just as you would with an Arduino. There’s a real-time clock, servo headers, plenty of ways to power the board, and even a breakout for this GPS module.
A lot of unnecessary cruft is done away with in the AlaMode; There’s no USB port, but it can be programmed directly over the GPIO pins of the Raspberry Pi. Pretty neat, and we can’t wait to grab one for our Raspi.