Puzzlemation - Frequently Asked Questions

When I showed Puzzlemation at the Bay Area Maker's Fair, people had a number of questions. Here's an FAQ:

• How do the tiles communicate with each other?
  They don't. The tray controller (PCB to the left in the photo) broadcasts the animation to the tiles via the copper strips running across the tray. The tiles have spring loaded contact pins to pick up the data. The data is sent as 9600 baud serial. Each tile has a uniquie identifier. A tile listens to the broadcast, and picks up the animation data when it's portion of the animation is sent. A "start" command is then broadcast. Once the start command is sent the tiles are free running. Crystal controlled clocks on each tile keep them in sync. The copper strips are only used for sending data when the animations are broadcast. Each tile has its own battery power.
  
  
• How do the tiles know where they're located?
  They don't. If you mix up the the tiles, the animation is mixed up. Putting them back in order is where the "puzzle" in Puzzlemation comes from.
  
  
• How do you create the animations?
  Anything that makes a series of PNG files or an animated GIF works. I've used both Adobe Flash and Photoshop to produce animations. I also had our kids make cut-out animations with red, green and yellow construction paper, which were then photographed. These were processed in Photoshop and made into animations.
  
  Once the animation is in PNG/GIF format, I have a Python script that chops the image and produces the bitmapped format used by Puzzlemation. This is downloaded into the tray either via an SD Card or Ethernet.
  
  
• How long do the batteries last?
  In theory they should go for at least six hours, but in practice they've done better than that. It depends on the duty cycle of the paricular animation. I've had great luck using Eneloop AAA batteries. Come to think of it, 32 AAA's (two per tile) is actually a lot of juice...25 A/hr to be exact. Each tile has a boost voltage regulator (based on the Minty Boost design). This provides a stable 3.3v source even as the batteries run down, and help suck every last electron out of them.
  
  
• What chip did you use?
  Each tile has a PIC24FJ64GA004 microcontroller. This is a 16 bit chip, programmed in C with Microchip's MPLab IDE. The tray uses a PIC24FJ64GA002 (same chip w/28 pins). It runs a TCP/IP stack and a FAT file system on the SD card, using libraries available for free from Microchip. Not bad for a $3 chip with 60K of code. A ULN2803 provides the current drive to run the LED display. The LED matrix displays are from SparkFun.
  
  
• How much do the tiles cost?
  For my prototype it ran about $63 per tile, but $33 of that was for PCB fabrication. I was on a contest deadline when I made the PCB's so I paid a premium for getting them done quickly. With a longer lead time, the PCB's would run about $3-5/tile. Even purchasing components in large quantities it'd be tricky to get the parts cost below $15 / tile.
  
  
• Are you selling them?
  At the moment, it's not a commercial venture. It's a bit pricey for the toy market. The use of SMD components limits the market for selling kits.
  
  

Back to Puzzlemation