Posted by Lloyd Emelle | tagged: Ryan Howard, accelerometer, sports, celebrities

When I write my memoirs (my Guru-ography?) this one will be a special highlight. Sure, throwing out the first pitch at a Phillies game was cool, but how could I describe the chance to take swings with an MVP slugger, based on a tech invention I worked on? I believe the word would be Phantastic.

(New video: click here to see more interview footage with Ryan Howard, including the secret to his powerful swing!)

Everyone knows how fast the fastest pitcher pitches. But what about how quick the hottest hitter hits? Our mission: hack a bat with an accelerometer to find out. Then we thought, what if we added a wireless transmitter? And a gyroscope? Then you could profile a batter’s unique swing style.

Ryan Howard not only tried out our Hack-a-Bat, he offered some great insight on the science of the swing. And then he took the time to give a batting clinic to the little league team in Abington, PA, home of the Wurtzes.

MATERIALS:

* 34-inch baseball bat
* 1 ½ inch spade bit
* 3-axis accelerometer
* Gyroscope
* Microcontroller
* Wireless transmitter
* 3-volt lithium ion battery
* Data visualization software
* Foam padding
* Anti-static bag
* LED light display

STEP 1: Make a hole in your bat

You’ll need a place to put the electronics. Using your spade bit, bore out a hole at the end of your bat, two and a half inches deep, and one and a half inch in diameter.

STEP 2: Drill holes for LED lights

Drill 8 quarter-inch holes around the bat. The LEDs will light up during your swing.

STEP 3: Assemble the circuit

Test the circuitry on a breadboard, according to data sheets for each component. Connect them to the computer with a USB serial converter, and check that they are delivering data.

Solder header pins to the transceiver and the accelerometer and gyroscope sensors. Use wire wrap on header pins to make the connection. Insulate the connections with hot glue. Now connect the microcontroller to the IC socket, and connect the header pins from the microcontroller to the header pin socket that is connected to the LED light array. Wire-wrap the pins on IC socket so that microcontroller can be removed from the socket.

The microcontroller processes information from the accelerometer and gyroscope, and sends that to the transceiver, which sends it wirelessly to the computer.

STEP 4: Protect the electronics

Take the anti-static bag and place it around the electronic components, which should shield it from any electrical noise generated throughout the swing. Place the foam padding around the anti-static bag, and stuff them into the bat. Then insert the battery.

• Save Those Pink or Green Bags

  Anti-static bags included with electronics can be used for other projects! more

STEP 5: Cap the bat

Cap off the end of our bat, and seal it up with hot glue, and we’re ready to swing away.

STEP 6: Present the 2.0 Bat to Ryan Howard

If you don’t have a 2006 National League MVP on hand, present the bat to a young future MVP.

STEP 7: Track swing with data visualization software

The Hack-a-Bat software is an application from guest gurus Joel Murphy and Marcus Pingel. (You can download the software here; recommended for use with Mac computers.) They wrote it in the C++ programming language using the Xcode Developer Tools on a Mac. It was created using the openFrameworks C++ library version 0.05. openFrameworks is a great opensource project actively developed by Zach Lieberman and Theodore Watson along with help from the OF community. For more information check out open Frameworks.

First we established serial communication between the microcontroller reading the data from the accelerometer and gyroscope and the Hack-a-Bat software running on the computer. Then we wrote a program to visualize this data.

The Microcontroller in the LED display receives a signal from the Visualization software on the laptop. Upon receiving the signal, the Microcontroller retrieves the wireless data transmission from the bat. Then it sends that data to the Visualization software. The Visualization software requests data 60 times per second, in time with the video frame-rate.

The blue line is the y-axis of the accelerometer. The green line measures the swing speed. An elevated green line indicates a faster peak swing speed. The yellow and red lines, taken from the gyroscope, show how the position of the bat changes during the swing. They provide a graphic of the swing style.

Dig deeper into the science with Hack-a-Bat 101:

1. Introduction

2. The Bat's Circuit