Propeller display device - V2.0
Introduction
As you remember from the Version 1 of the propeller clock, the purpose of this device is to write things (like a clock or a textual message) in thin air!
The device consists of a row of 8 LED's and some other electronics parts mounted on a motor. While this motor is running, the LED's are switched on and off on specified intervals.
Because it takes a while before an image projected on a humen eye fades out, we can play a mindtrick by writing a whole circle of text before your eye notices it's gone...
Changes since Version 1
As you might notice, the cosmetics of this device are somewhat smoother than the previous version.
In particular, the arm that holds the LED's was made as thin as possible. I used wires of an old coil I found somewhere to wire the LED's to the resistors. While heating these wires, the plastic shield that surrounds these tiny wires melts, so it allows you to safely attach them to both sides of the print, without risking to short circuit the propeller display.
The chip I used was a PIC16F48A-20 which runs at a clockspeed of 20Mhz. This is the only difference with the 4Mhz version.
Software
Because my Linux programmer didn't allow me to program the 16F84A (serial port timing issues?), I had to use some Windows tools to get my PIC programmed.
- c2c a c-compiler for Rapid Application Development on your PIC. After all, you want to see a result on your propeller display, instead of wasting your time mangling with that PIC assembly language. I used the mpasm assembler of Microchip to compile the assembler code into a .hex file.
- icprog to program your HEX code to the PIC. If you use the programmer of the old version of this device, in icprog, it's called a 'JDM programmer' and the configuration is like this: Oscillator: HS , Fuses : WDT off , PWRT on, CP off.
Some clickable close-up pictures of the device
The device, when finished.
Here is a detail of the tiny wires that are attached to the LED's. A nerve job...
Here is the other side of the LED arm. Notice the tiny wires as they are attached to their resistors.
LED's in the spotlight.
Result
And here's the result when you feed 5V DC into this construction:
the outer LED is attached to the current, and as you can see - it is blue. The red glow comes from my optical mouse.
The letters are really clear on this diplay device. They are also not deformed, like the letters on version 1.
The LED's don't have a very wide angle. Therefore it is necessary to look at it from the top.
http://www.ponnet.com/projects/propeller/
