Tennis practice for hackers


Here’s an interesting WiiMote based project. [Mans] is a tennis fan, though a bit out of practice. With the tennis season coming to a rather climactic end, he got excited and wanted to brush up on his skills. He found the toss part of his serve to be very sloppy. Being a hacker, the first thing he thought was that there must be some way of tracking and graphing his toss so that he could improve it in an intelligent and controlled manner. The WiiMote seemed a perfect fit for this. Only a small modification was necessary, an external button wired to the internal “-” button. This switch is active while he’s holding the ball, and inactive when the ball is released. In this manner, he can track and chart his toss to find out exactly where he needs improvement.  He uses [Johnny Chung Lee]’s code, with a small but unspecified modification to write the accelerometer data to a text file.

As he points out, this could be very usefull for any repetitive movement. Whith accelerometers getting cheaper and cheaper, there’s nothing stopping you from using multiple ones either. Imagine a golf rig to analyze your swing, Maybe a boxing rig that measured your hip twist and arm extension, or possibly a yoyo glove to tell you if your flick needs some help. Great job [Mans].

Wii Balance board

[Matt Cutts], head developer for google’s anti spam team, describes how to attach a Wii balance board to a linux computer. He even shows how to make a GUI to show the input. The entire project is done in about 200 lines of python.The process assumes that you can already make a bluetooth connection to a WiiMote, but if you can’t, he’s got instructions for that too.

[via hackawii]

Wii MotionPlus + Arduino


[knuckles904] was able to use the new Wii MotionPlus with an Arduino. Nintendo has released the WM+ in order to detect the motion of the controller better. The Wiimote only detects acceleration, whereas the WM+ detects rotation along 3 axes. The Arduino communicates with it over I2C, the same protocol that is used with the Nunchuk. To connect the two devices, he used jumper wires, but breakout boards are also available. He was able to create some example code with help from When paired with a Nunchuk, which contains a 3-axis accelerometer, you can have a 6 degrees-of-freedom IMU for under $40, perfect for controlling your robots or logging data.

[via adafruit]

Wii nunchuck controlled Pleo

[Andy] wrote in to show us how he hacked his Pleo to be controlled by a Wii Nunchuck. He has installed Xbee units for the communication as well as written a “skit” that allows the Pleo to just stand there and wait for commands. He is using an Arduino to interpret the Nunchuck input and send it to the Pleo. It’s a pretty cool proof of concept, but the response time is pretty slow. This might be due to the Arduino’s slower serial communication rate.  Yes, we said you might want to refrain from hacking them, due to their impending extinction, but did you expect us to stick to that? If you’re going to dig into one, you may also be interested in how to hack the Pleo for face recognition and remote control.

Wii controlled segway style NXT bot

When [Epokh] sent in this Wii controlled segway style bot, we remembered a post a few months ago where someone made a balancing bot, but hadn’t completed the Wii code. Well, [Epokh] is going to show you how to implement the Wii controls with the Lego NXT system. He’s found the links to all the software you need and broken down the configuration step by step. He’s been busy lately, let’s hope he keeps it up.

Wiitar, a build log


[Ozan] sent in this build log from when he made a Wiitar. As you can probably guess from the title, it’s a guitar combined with a wiimote. He has completely gutted the Wiimote and installed the internals in the guitar. Some toggle switches were mounted to control the button states on the Wiimote.  This is a pretty useful setup as you can use the Wiimote data to control effects on the guitar. We’ve actually seen a very similar setup before. [Ozan] has included the build log, as well as a simple glovepie script and a sample effect patch.

Rocket acceleration logger


Have you ever wondered how high or how fast a model rocket goes when you launch it? [sprite_tm] did, so he decided to build a low cost, lightweight data logger that he could fit into the nose cone of his rocket. To keep the circuit small, he built it around the popular ATtiny13 microcontroller. The microcontroller collects data from a Freescale MMA7260, a 3-axis accelerometer that he extracted from a third-party Wii nunchuck controller. After the microcontroller collects the data, it’s stored in 32K of EEPROM on a 24C256. All of this is powered by a small 3.6v Li-ion battery, which is the largest part of the circuit. If this sounds like something you’d like to make, he has detailed instructions along with the software used available on his site. While we don’t launch a lot of model rockets here, we may soon start just so that we have an excuse to build this.