Roll Your Own Trackball Mouse

What do you do when you’re into trackball mice, but nothing out there is affordable or meets all your murine needs? You build one, of course. And if you’re like [Dangerously Explosive], who has a bunch of old optical mice squeaking around the shop, you can mix and match them to build the perfect one.

The mouse, which looks frozen mid-transformation into a rodential assassin, is a customized work of utilitarian art. Despite the excellent results, this project was not without its traps. [Dangerously] got really far into the build before discovering the USB interface chip was dead. Then he tried to sculpt a base out of Plasticine and discovered he’d bought the one kind of clay that can’t be baked. After trying his hand at making homemade salt dough, he painstakingly whittled a base from scrap pine using a drill and a hacksaw.

Every bit of this mouse is made from recycled bits, which, if you pair that with the paint job and the chosen shade of blinkenlights, makes this a green mouse on three levels. One of the two parts of this mouse that isn’t literally green, the cord, is still ecologically sound. [Dangerously] wanted a really long tail, so he scavenged a charger cable built for fruity hardware and threaded it through a hollowed-out piece of purple paracord.

We love the thumb-adjacent scroll wheel and the trackball itself, which is a ping pong ball painted black. The cool part is the guide it rolls around in. [Dangerously] spent a long time hand-whittling the perfect size hole in a particularly wide mouse palm rest. All that plastic shaving paid off, because the action is smooth as Velveeta.

[Dangerously] certainly designed this mouse to fit his preferences, and ergonomics seem a bit secondary. For a truly custom fit, try using whatever passes for Floam these days.

Mouse Brains Plus Line Laser Equals Rangefinder

[Neumi] wrote in with a sweet robotics hack. It’s a 2D laser distance sensor (YouTube) made with a cheap line laser and an optical mouse’s flow-sensor chip used as a low-resolution camera. In one sense, it’s a standard laser-distance-sensor project. But it is clever for a whole bunch of reasons.


For one, using a mouse sensor as a low-res camera is awesome. It’s designed to read from a standard red LED, so the sensitivity is in just the right ballpark for use with a line laser. It returns a 30×30 pixel greyscale image, which is just about the right amount of data for a low-end microcontroller to handle and keep up with the framerate without resorting to coding tricks.

It’s also no coincidence that these sensors are available with lenses built in, for relatively cheap, on eBay. Apparently the quadcopter gurus use them as if they were mice to visually track their quad’s motion. Hacker spillover!

Detecting the laser line as it reflects off of whatever objects are lying on [Neumi]’s floor could also possibly prove difficult, and might produce false readings in the presence of background illumination. So [Neumi] takes two readings with the camera — one with the laser on and one with it off — and differences them. Done fast enough, this should reduce any non-laser sources down to the sensor’s noise floor. Finally, there’s some thresholding and averaging going on behind the scenes that help make everything work out right. The code is up on GitHub.

Not a bad build for a 2D laser distance system on a budget. If you want to shell out a bit more money, and are into a seriously involved build, this is probably the slickest we’ve seen in a long time. And if you’re thinking that you’ve heard of [Neumi] before, you’re right: we featured this 405mm laser PCB exposer / burner CNC machine just a few months ago.

Continue reading “Mouse Brains Plus Line Laser Equals Rangefinder”

Hacklet 42 – Mouse Projects

Ever since [Douglas Engelbart] and his team came up with the computer mouse, hackers, makers, and engineers have been creating ways to change and improve the design. Even the original mouse was something of a hack, built form a block of wood, a button, and two encoder wheels. The wire exited toward the user’s wrist, making the device look like it had a tail. Even after all these years, folks are still working to make the perfect pointing device. This week’s Hacklet highlights some of the best mouse projects on!

mouseballzWe start with [s_sudhar] and ORB – A 3D gaming mouse. Orb uses accelerometers and gyros to track its location in 3D space. The popular MPU-6050 chip provides all the sensors to create an Inertial Measurement Unit (IMU). The controller is an Arduino Micro, which provides the USB interface to a PC with the help of Arduino’s MouseKeyboard library. Two micro switches handle button duties. The original Orb was built up in a cardboard box. [S_sudhar] created a more advanced version housed in a 3D printed sphere with two buttons. The translucent joint between the two halves of the sphere is just begging for some RGB LEDs. We can already see them flashing red when you’re getting shot in Team Fortress 2!

mouse-wheelAnyone who has used X-Windows with a three button mouse knows how maddening the modern clickable center scroll wheel can be. You can’t click the wheel without it rolling, and causing all sorts of mayhem. There are plenty of software solutions and window manager mods to work around this, but [mclien] wanted a real three button mouse with a side scroll wheel. He didn’t want just any mouse though – it had to be a Silicon Graphics International (SGI) 3 button unit. His project 3-buttonmouse with seperate wheel used a dremel, drill press, and glue to transplant the electronics of a 3 button scrolling mouse into the classic SGI plastics. The final wheel placement did work – but it didn’t quite fit [mclien’s] hand. It did fit one of his friends hands perfectly though. So well in fact that the friend borrowed [mclien’s] creation. Neither the mouse nor the friend have been seen since!

jimmy[Jay-t] decided that mice are for more than pointing, so he built Jimmy the mouse bot. Jimmy is a robot built from an old Commodore Amiga two button mouse. His brain is a Parallax Propeller processor. Two outrigger mounted gear motors help Jimmy drive around. Jimmy has plenty of sensors, including infrared object detectors, switches, and a GPS module from Adafruit. Jimmy may be the world’s first homing mousebot. [Jay-t] does all his interactive testing with Tachyon Forth on the Prop. The great thing about having an 8 core processor is that there is plenty of room for expansion. Even with all these sensors, Jimmy is still only using 3 cores!



Finally we at [Clovis Fritzen] and the Wireless Batteryless Mouse. This is our favorite type of project – the kind that has just been uploaded. [Clovis] plans to use a movement based system to charge up a supercapacitor – eliminating the need for batteries or wires. He’s also hoping to use an accelerometer to detect the mouse’s position rather than a power-hungry optical system. The details are still sparse, because he’s just started the project! These are exactly the type of projects that get us thinking. How will [Clovis] translate movement to energy? Will it be weights, like a self-winding watch? Maybe pizeo elements in the buttons. Will people mind having to jiggle their mouse to get it working once that capacitor is discharged? One thing we’re sure of, [Clovis] has a proven track record of implementing projects like his weather station. Get in there and help with your own ideas, or simply follow along with us and see how this one turns out.

Not satisfied? Want more mousy goodness? Check out our freshly minted mouse and pointer projects list!

That’s about all the time we have for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of!