So I continuously recived the question… “How do you change the message?” As I answered this many times before, I began to realize that my “you use an ISP programmer along with a bash script in linux” answer wasn’t going to cut it for most people. I started looking at alternatives, and finally settled on an HID implementation. I used Objective Development’s VUSB firmware (a firmware only USB implementation for AVR microcontrollers) along with a few additional components. (ceramic resonator, three resistors, two capacitors, a voltage regulator, and of course the USB mini-B connector) I also added an aditional LED because I could.
Now is where I talk about interesting things…
I use a small delay to detect whether USB is present, resulting in the small delay before the message starts. I had Room for the LED, so I added it so I could pull off our local protospace logo.
I also added a bit of code in firmware to allow additional characters to be stored in EEPROM. I figured people would like the option to add some of their own.
I created a simple C# app (visual studio 2010 ) to connect, communicate, and download new messages onto the device. It is include in the source as well.
I can’t really think of anything else right now.
Any questions can be added below…
And… The source! Available here: USB POV source (578)