Monthly Archives: March 2014

2014 Halloween project update

I have been sent a few things I will be using to make a prototype for the Halloween project. The main features will be playing audio on demand, and switching lights (or other 120V items) on and off in time to the audio. Here are the items I will be evaluating:

  • MP3 Shield ($19.99) from This shield has its own flash storage and lets you load MP3 files over from SD memory cards or USB thumb drives. In addition to control buttons on the shield itself (vol+/-, pref, next, play), it also has buttons to start up the copy operation and put the unit to sleep. There is a 1/8″ headphone style jack for getting audio out. It is controlled via serial (tx/rx) and can be made to play a specific track number off the memory.
  • Relay Shield ($7.59) from e-Bay seller happyvalley009. This shield has four relays that can handle 120V up to 3amps, which is a small amount but enough for our needs. It is dangerous to run 120V in to a shield like this, as a short could really cause some problems. A better solution might be to use a separate relay board ($8.49 with Amazon Prime shipping) that is controlled without being attached to the Arduino itself. That would let it be physically separate and still be controlled the same way (and, this one can handle more amperage).

As soon as my funding source returns from vacation, we will order more items and begin working on a prototype.

Pac-Man source code now on GitHub

For those who wish to follow along with my Pac-Man project without having to copy/paste source code from these articles, I have posted my current work-in-progress source (which includes many changes I have not discussed, yet).

I have broken the program up in to multiple files, but since this makes quite a mess in the IDE, I am probably going to combine all the bitmaps in to one file instead of separate ones.

If you want to play with it, you can modify the Joystick code to read whatever you have for input (buttons, analog joystick, whatever) and at least move the Pac-Man around the screen. There is no ghost collision detection, no scoring, and no dot handling yet… But it’s a fun demo.

Arduino ethernet for $10

Here is a heck of a deal. This Arduino Ethernet Shield uses the WizPro 5100 like the official Arduino shield:

If this $10 shield works the same, it is a very cheap way to get internet connectivity out of an Arduino. If you get one, let me know how it works for you.

The shield I used for my Ethernet experiments was made by Sainsmart and it runs about $20:

And for those who don’t want to wait for mail order (from China?), you can get a $20 Seeed ethernet shield at your local Radio Shack:

Pretty cool.