Gizmo's Projects: CGMMSTICK Vacuum Fluorescent Display Example

I've had a couple of these display modules setting around for a while. They have a 10-pin connector, not the 'normal' 14 that an LCD module has. I also don't have a data sheet for the display, but a couple of old data sheets for different displays. Every time I bump into the modules in my box of stuff I wonder what they look like when activated.

I decided to wire up the display to a CGMMSTICK1 to test them. It is a 5V display, so I used OC outputs pulled to 5V through a 10k resistor. The display has a reset line, data in, and clock. Data is most significant bit first.

Pins 2, 4, 6, 8, 10 are ground

Pin 1 +5V

Pin 3 clock

Pin 5 data

Pin 7 reset

The value that it takes to write "A" is 1, "B" is 2. This doesn't follow ASCII. Below is the code I used to test the display:

' VFD test code

' I/O init
' Open collector data
SETPIN 12, 9 : PIN(12) = 1

' Open collector clock
SETPIN 13, 9 : PIN(13) = 0

' Open collector reset
SETPIN 15, 9 : PIN(15) = 1

' Values for characters
_A = 1 : _B = 2 : _C = 3 : _D = 4 : _E = 5
_F = 6 : _G = 7 : _H = 8 : _I = 9 : _J = 10
_K = 11 : _L = 12 : _M = 13 : _N = 14 : _O = 15
_P = 16 : _Q = 17 : _R = 18 : _S = 19 : _T = 20
_U = 21 : _V = 22 : _W = 23 : _X = 24 : _Y = 25 : _Z = 26

_AT = 0 : _SPACE = 32

_ZERO = 48 : _ONE = 49 : _TWO = 50 : _THREE = 51
_FOUR = 52 : _FIVE = 53 : _SIX = 54 : _SEVEN = 55
_EIGHT = 56 : _NINE = 57

' Initialize and display message
VFDRESET

VFDDATA _SPACE
VFDDATA _C
VFDDATA _I
VFDDATA _R
VFDDATA _C
VFDDATA _U
VFDDATA _I
VFDDATA _T
VFDDATA _SPACE
VFDDATA _G
VFDDATA _I
VFDDATA _Z
VFDDATA _M
VFDDATA _O
VFDDATA _S
VFDDATA _SPACE

END

' VFD display reset routine
Sub VFDRESET

' pulse the reset line
PIN(15) = 1 : PAUSE 1
PIN(15) = 0 : PAUSE 1
PIN(15) = 1 : PAUSE 1

' Clear the display
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
VFDDATA &h20
' Turn display on
VFDDATA &hFF

End Sub

' Write data to display, MSB first
Sub VFDDATA (valu)

PIN(13) = 1

PIN(12) = valu AND &B10000000
PIN(13) = 0 : PIN(13) = 1

PIN(12) = valu AND &B01000000
PIN(13) = 0 : PIN(13) = 1

PIN(12) = valu AND &B00100000
PIN(13) = 0 : PIN(13) = 1

PIN(12) = valu AND &B00010000
PIN(13) = 0 : PIN(13) = 1

PIN(12) = valu AND &B00001000
PIN(13) = 0 : PIN(13) = 1

PIN(12) = valu AND &B00000100
PIN(13) = 0 : PIN(13) = 1

PIN(12) = valu AND &B00000010
PIN(13) = 0 : PIN(13) = 1

PIN(12) = valu AND &B00000001
PIN(13) = 0 : PIN(13) = 1

End Sub

And the result: