If you want to see what kind of abuse you’re causing your body when out on those single-track rides this system is just the thing. It’s an Arduino data logger that [Wdm006] takes along on the rides with him. When he gets back home, a Python scripts captures the data dump and graphs it. It may sound like a neat trick, but he’s got something planned for that information.
The enclosure mounts to the stem of his bike. It houses an Arduino board with a data logging shield of his own design. That shield holds an SD card for storage, and breaks the other pins out as screw terminals. Right now there’s an accelerometer on the front fork, and some method of recording wheel speed. This is the research phase of an anti-lock brake system (ABS) he plans to build for mountain biking. No word on what hardware he’ll use for that, but we can’t wait to see how it comes out.
There’s a good chance that you use a MEMS accelerometer every single day. It’s the small chip that let your smart phone automatically adjust its screen orientation. They’re great chips, and since they’re mass-produced you can add them to your projects for a song (if you can abide the tiny packaging). But we have no idea of how they are made and only a inkling of how they work. [Bill Hammack] has filled that knowledge gap with this explanation of how MEMS accelerometers are made and how they function.
Our base knowledge comes from the acronym: Micro Electro-Mechanical Systems. There’s something in the chip that moves (so much for solid state electronics; and it makes us wonder if these wear out). [Bill] includes a diagram in his video after the break which shows the silicon-based system that moves as it is affected by gravity. This changes the capacitive properties of the structure, which can be measured and reported to a microcontroller for further use. The structure is built using an intricate etching process which we never want to try out at home.
Looking for a project in which to use one of these devices? We’ve always been fond of this POV device.
Continue reading “The Engineer Guy explains how MEMS accelerometer chips work”
[Chris Suprock] is interested in using technology to improve your accuracy with a firearm. To that end, he’s using an Accelerometer mounted to a gun to gather feedback about each shot.
The hardware setup is pretty simple. We don’t have specific details, but it looks like he’s using a QFN accelerometer chip like you would find in a cellphone. The milled aluminum mounting bracket that holds the board has ‘USB’ printed on it, although the connector is something we don’t really recognize.
In the video after the break [Chris] demonstrates the feedback he can get when the device is mounted on the stock of a Ruger Mini-14. The graph of the data makes it obvious when the trigger was pulled. The most useful part may be the period leading up to that event, as it shows any unnecessary movement prior to the shot. If you’re into sport shooting, this may be one more tool that will help give you the edge on your competitors.
Continue reading “Accelerometer may help make you a sharpshooter”
[Kevin Osborn] is making it a bit easier for young programmers to write programs that interact with the physical world. The device he’s holding in the picture is an Arduino based accelerometer and distance sensor meant for the Scratch language.
Scratch is a programming language developed at MIT. It has kids in mind, and focuses on graphical building blocks. This can make it quite a bit easier to introduce youngsters to programming concepts without the roadblocks and gotchas that come with learning syntax.
As you can see in the clip after the break, [Kevin's] Arduino sketch includes hooks that automatically pull the accelerometer and distance data into the Scratch environment. We figure his example provides everything you need to get just about any type of sensor up and running, be it a magnetometer or LDR (both of which would make a nice burglar-alarm type project). Give it a try with your own hardware and see what you can accomplish.
Continue reading “Building sensors for the Scratch programming language”
[Rob Morris] has been hard at working improving his guitar augmentation techniques. Here he’s demonstrating the use of an iPhone to control the effects while he plays. This builds on the work he shared a few years ago where he strapped a Wii remote to the body of his ax.
Just like the Wii remote, the iPhone includes an accelerometer. As you would expect the best parts of the older hack made it into this one, but the inclusion of the touch screen adds a lot more. In the clip after the break he starts by showing off the screen controlling a whammy bar functionality. But we really love the octave offset feature that comes next. This kind of sound manipulation simply can’t be done using a purely physical method (like the whammy bar can). But he’s not done yet. The demo finishes with a Theremin feature. You’ll notice he plucks a string but no sound comes out until he starts touching the screen. This turns it into an entirely different type of instrument.
The only info we have about putting this together is the list of packages he’s using: TouchOSC, Max/Msp, and GuitarRig
Continue reading “iPhone wielding guitar adds tip of your finger or tip the instrument control”
[Ben Peoples] works in theatrical electronics. Sounds like fun, and here’s an example of the kind of stuff he does. We’re not sure what event this installation was used for, but if the elevator ride needed something flashy just think of what the party room must have looked like. These HDTV screens on the ceiling of the elevator play different clips when the elevator is moving up or down. The challenge for [Ben] was to find a way to make it work without tapping into the elevator electronics or requiring any button presses.
The first attempt at sensing the elevator’s travel was done with an accelerometer. The problem with this approach is that an accelerometer only senses change in acceleration and this method proved to be fairly error prone. [Ben] switched over to a reflective sensor which performed quite well. Since most of these sensors will only work within about an eighth of an inch he ended up building his own with a LDR and a couple of amber LEDs.
[Sam] is working on his Interactive Technology Degree and he made some alterations to this guitar as a class project. It doesn’t look much different, but closer inspection will reveal a handful of extra buttons, and a camera module. He actually added a Wii remote to the guitar which is used to control Max/MSP.
His pinky is pointing at one of the buttons. That one is red and triggers the Bluetooth sync function for the Wii remote. The other four buttons are wired to the up, down, A, and B buttons. In the video after the break [Sam] talks about the Max/MSP front-end which is used to connect the remote to the computer. Once communications are established the accelerometer sensor data is continuously streamed to the software, and the other four buttons are used for controlling the patches.
The camera module that is mounted in the guitar can be used to stream video but it appears to have no effect on the sound. In fact, the live video feed can be mixed with a waveform generation. Sound characteristics like volume affect the cross-fade between the two video signals. [Sam] talks about this feature, but when the playing demo starts about 6:10 into the clip we don’t seen any of the live video on the projection screen.
Continue reading “Inconspicuous guitar hack adds a lot of control to Max/MSP”