It took me quite a while to get everything drawn out and even longer to get it all soldered and working, but it was a great learning experience and super fun.
This is the entire unit... arduino, i2c multiplexing shield, equalizer shield, bluetooth breakout board, 4 ADXL 345 accelerometers, and an electret microphone. Only things missing from the shot are the 450 LED pixel points, the 6v 12Ah sealed lead-acid battery, and another battery to run this unit (I'm going to run the lights and controller off of separate batteries).
 |
| LightWalker's guts. |
This is the i2c multiplexing shield with TCA9548A i2C switch. It allows me to hook up the 4 accelerometers that all have the same i2c hardware address to a single i2c line. The board can handle up to 8 units with the same address, so maybe I should do a spider for next year?
The big trick here was that I hooked up my SCL and SDA lines to where they were printed on the board but failed to realize that the board didn't connect those to the arduino's analog 4 and 5 pins like my board needed. I think newer boards would work through the stackable headers and the SCL and SDA holes printed on the board. Once I realized I was working with an older setup and re-routed them, all was good.
 |
| bottom of the i2c multiplexing shield |
 |
| top of the i2c multiplexing shield |
Here's the equalizer shield. I'm only using one of the MSGEQ7 chips on here for a single audio channel, so it's kind of overkill, but it does give me a nice stackable shield and pins to hook the microphone and bluetooth to.
 |
| equalizer shield w/ electret microphone |
And, just for completeness, the arduino compatible shield from seeedstudio...
 |
| the seeedstudio arduino compatible board I'm using |
