LED Messaging Waver

LED Messaging Waver ( using persistence of Vision to create letters and words)

The circuit consists of LEDs tied from the 7 pins of portd to the first 7 pins of portb. The remaining pin (portb.7) can be used to switch to different messages or change colour….

This pin is connected to a button with a 10K pull up resister to +5V and a micro switch to GND.

(not shown on this schematic)

All the LED's are Bi coloured green and red. There are 7 in total.

This works best if the display is spun in a circle or waved left and right....The flashing LEDS when moved left and right will create the illusion of floating letters in the air. This is known as persistence of vision.

When waving the display right and left the message is displayed forwards then backwards on the back swing. If rotated clockwise the message remains correct. With perhaps some timing changes or a mercury switch that detects forward motion only, the message can be turned off when swinging back… any takers? I will look into this…..

When waving the display with your hands to the right the words are displayed correctly as you swing back to the left….the letters are displayed reverse.

If you are spinning the display in a circle clockwise the display should read correctly.... have fun with it... Bring it a rave and wave it around with your personal message....

The led's should be as close as possible so the words do not appear to "dotty"

The above pictures were taken with a digital camera in a darkened room.

P.S. Squeezy is my wife….
The included BASCOM-AVR program uses an AT90S2313 Atmel chip program will display two sentences one in green and one in red. The messages used in the example program consist of a 7X7 matrix .... but it could really be 7 vertically by anything….because values are calculated vertically.

Please refer to the table below (matrixletter.gif) for the whole alphabet.

Here is a picture of the one I built on a perf board. Included in the zip file are all the images as well as a PC Board layout in Eagle 4.09.

The following 2 BASCOM-AVR programs are used to display the messages on the LEDs. Please note using the above table you can make it display what ever message you like. You can even do graphics if you like. I built a similar one using 8 red LEDs from portb to gnd that allowed me an 8 X 8 matrix for graphic characters and letters.…The programming is simpler (Listing 2)

Listing 1 – two text messages two colours.

'I used an ATMEL AT90S2313 20 Pin chip.

'I built it with a 5volt regulator and 4 mhz resonator.

'7 bi-coloured LEDs are attached from Portd to Portb with a current limiting resister.

'Portd.0 to Portb.0

'portd.1 to Portb.1

'Portd.2 to Portd.2

'Portd.3 to Portd.3

'Portd.4 to Portd.4

'Portd.5 to Portd.5

'Portd.6 to Portd.6

'Portb.7 to pull up resister and momentary switch to gnd.

'This switch can be used to goto a subroutine to change colour or between messages....

'currently not using it with this Application Note.

Dim A As Byte , B1 As Byte , C As Byte

Config Portd = Output

Config Portb = Output

Start:

Portb = 00 'set Portb to all low to display text in Red.

For C = 1 To 40 '147 bytes to send to the display, loops 147 times.

Restore Xxx 'displays the message 40 times before switching to

For A = 1 To 147 'second message.

Read B1 : Portd = B1 'sending text info to portd

Waitms 1

C = 0

For C = 1 To 40

Portd = 0 'set Portd to all low to display text in Green.

Restore Yyy '2nd message to be displayed in Green 40 times

For A = 1 To 140 'with 140 bytes of data to the displays to make up the message.

Read B1 : Portb = B1 ' sending text info to portb

Waitms 1

Goto Start

End

'Red Message

Xxx:

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Data &H7F , &H01 , &H01 , &H01 , &H01 , &H00 , &H00 'l

Data &H3F , &H41 , &H41 , &H41 , &H3F , &H00 , &H00 'o

Data &H78 , &H06 , &H01 , &H06 , &H78 , &H00 , &H00 'v

Data &H7F , &H49 , &H49 , &H41 , &H00 , &H00 , &H00 'e

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Data &H3F , &H40 , &H40 , &H3F , &H40 , &H40 , &H3F 'm

Data &H3E , &H01 , &H01 , &H01 , &H3E , &H00 , &H00 'u

Data &H7F , &H48 , &H48 , &H40 , &H00 , &H00 , &H00 'f

Data &H00 , &H00 , &H7F , &H00 , &H00 , &H00 , &H00 'i

Data &H7F , &H20 , &H1C , &H02 , &H7F , &H00 , &H00 'n

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Data &H3F , &H41 , &H41 , &H41 , &H3F , &H00 , &H00 'o

Data &H7F , &H48 , &H48 , &H40 , &H00 , &H00 , &H00 'f

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Data &H7F , &H01 , &H01 , &H01 , &H01 , &H00 , &H00 'l

Data &H3F , &H41 , &H41 , &H41 , &H3F , &H00 , &H00 'o

Data &H78 , &H06 , &H01 , &H06 , &H78 , &H00 , &H00 'v

Data &H7F , &H49 , &H49 , &H41 , &H00 , &H00 , &H00 'e

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

'Green Message

Yyy:

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Data &H00 , &H00 , &H7F , &H00 , &H00 , &H00 , &H00 'i

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00 '

Data &H7F , &H01 , &H01 , &H01 , &H01 , &H00 , &H00 'l

Data &H3F , &H41 , &H41 , &H41 , &H3F , &H00 , &H00 'o

Data &H78 , &H06 , &H01 , &H06 , &H78 , &H00 , &H00 'v

Data &H7F , &H49 , &H49 , &H41 , &H00 , &H00 , &H00 'e

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Data &H40 , &H20 , &H1F , &H20 , &H40 , &H00 , &H00 'y

Data &H3F , &H41 , &H41 , &H41 , &H3F , &H00 , &H00 'o

Data &H3E , &H01 , &H01 , &H01 , &H3E , &H00 , &H00 'u

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Data &H32 , &H49 , &H49 , &H49 , &H26 , &H00 , &H00 's

Data &H3E , &H41 , &H45 , &H43 , &H3F , &H00 , &H00 'q

Data &H3E , &H01 , &H01 , &H01 , &H3E , &H00 , &H00 'u

Data &H7F , &H49 , &H49 , &H41 , &H00 , &H00 , &H00 'e

Data &H43 , &H45 , &H49 , &H51 , &H61 , &H00 , &H00 'z

Data &H40 , &H20 , &H1F , &H20 , &H40 , &H00 , &H00 'y

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Listing 1 – two text messages single colour.

' I used an ATMEL AT90S2313 20 Pin chip.

' and built it with a 5volt regulator and 4 mhz resonator.

'8 superbright red LEDs are attached from Portb to Gnd through a current limiting resister.

'Portd.2 to pull up resister and momentary switch to gnd.

'This switch can be used to goto a subroutine to change between messages....

'currently not using it with this Application Note.

Dim A As Byte , B1 As Byte , C As Integer

Config Portb = Output

Wait 2

Start:

Portb = 00

For C = 1 To 100

Restore Xxx 'gets data from the XXX table.

For A = 1 To 32 'there are 32 bytes of data so it loops 32 times

Read B1 : Portb = B1 'values from the table are output to the LEDs.

Waitus 400 'determines the width of each letter

Next 'the first message is I love U with a heart shape

Waitms 1 ‘for the word love.

C = 0

For C = 1 To 100

Portb = 00

Restore Yyy

For A = 1 To 119

Read B1 : Portb = B1

Waitus 400 'determines the width of each letter

Next '119 bytes of data to display the message here

Waitms 1 'so the loops goes for 119 times.

Goto Start

End

Xxx:

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Data &H81 , &HFF , &H81 , &H00 , &H00 , &H00 , &H30 , &H48

Data &H84 , &H82 , &H41 , &H82 , &H84 , &H48 , &H30 , &H00

Data &H00 , &H00 , &HFE , &H01 , &H01 , &H01 , &HFE , &H00

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Yyy:

Data &H00 , &H00 , &H7F , &H00 , &H00 , &H00 , &H00 'i

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00 '

Data &H7F , &H01 , &H01 , &H01 , &H01 , &H00 , &H00 'l

Data &H3F , &H41 , &H41 , &H41 , &H3F , &H00 , &H00 'o

Data &H78 , &H06 , &H01 , &H06 , &H78 , &H00 , &H00 'v

Data &H7F , &H49 , &H49 , &H41 , &H00 , &H00 , &H00 'e

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Data &H40 , &H20 , &H1F , &H20 , &H40 , &H00 , &H00 'y

Data &H3F , &H41 , &H41 , &H41 , &H3F , &H00 , &H00 'o

Data &H3E , &H01 , &H01 , &H01 , &H3E , &H00 , &H00 'u

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

Data &H00 , &H02 , &H01 , &H01 , &H7E , &H00 , &H00 'J

Data &H3E , &H01 , &H01 , &H01 , &H3E , &H00 , &H00 'u

Data &H7F , &H01 , &H01 , &H01 , &H01 , &H00 , &H00 'l

Data &H00 , &H00 , &H7F , &H00 , &H00 , &H00 , &H00 'i

Data &H7F , &H49 , &H49 , &H41 , &H00 , &H00 , &H00 'e

Data &H00 , &H00 , &H00 , &H00 , &H00 , &H00 , &H00

For comments or more information you can contact me on the Bascom-AVR mail list.

I hope you enjoy this fun project.

: )