A three colour LED show

I happened to come across some two-colour LEDs the other day and put them together into this little project. Each LED contains separate red and green LEDs, allowing three colours, because when both are lit a peculiar orange effect is produced. The layout is very simple. The eight cathodes are connected to the eight output ports of the Velleman board. The anodes of the two groups are connected together and driven - via a BFY52 transistor - by the two DAC of the board. This arrangement allows three colours to be selected and it also permits the brightness of output to be regulated.

Below is the circuit diagram and a suggested PCB layout.

The program

The program is written in the form of a short demo, which runs through various colour patterns and finishes with a slow fade-out. The LED to be lit is selected with the statement:

SYS K8055_SetDigitalChannel%,O%(J%)

Where O% is an array that holds the place value of the LED. This is needed because the LEDs are not connected in the right sequence. The different colours are selected by the statement:

SYS K8055_OutputAnalogChannel%,N%,I%

N% is the channel number. When this is 1, the red LED is selected, when it is 2, the green LED lights up. To get the orange colour, both LEDs must be lit: Like this:

SYS K8055_OutputAnalogChannel%,1,I%

SYS K8055_OutputAnalogChannel%,2,I%

I% is a number between 0 and 255 which selects the output voltage of the DAC - 255=5V. To fade the LEDs this number can be slowly changed from 255 to a lower value. Like this:

FOR J%=255 TO 180 STEP-1
SYS K8055_OutputAnalogChannel%,2,J%
TIME=0:REPEAT UNTIL TIME>5
NEXT

As usual I supply a zip archive with the BBC BASIC for Windows program file and a stand-alone exec file

There is also a

And here are the two files for the K8061

10 REM LED-Tricolour 20 REM Drive 8 2-colour LEDs with the K8055 30 REM (c) Jochen Lueg 40 REM 50 REM Limavady, January 2012 60 REM Vers 1.0 70 80 COLOUR 128 90 CLS 100 COLOUR 15 110 ON ERROR PRINT REPORT$;" at line ";ERL : END 120 PROCK8055_init :REM Setup all system calls 130 PROCinit 140 SYS K8055_OpenDevice%,Board% 150 PROCsay_hello 160 PRINT "Here we go" 170 180 PROCturn_right 190 PROCswap 200 PROCsay_hello 210 PROCfadeout 220 SYS K8055_ClearAllDigital% 230 SYS K8055_ClearAllAnalog% 240 SYS K8055_CloseDevice% 250 END 260 270 280 DEFPROCturn_right 290 SYS K8055_ClearAllDigital% 300 SYS K8055_ClearAllAnalog% 310 320 SYS K8055_OutputAnalogChannel%,2,255 330 FOR I%=1 TO 3 340 FOR J%=1 TO 8 350 SYS K8055_SetDigitalChannel%,O%(J%) 360 SYS K8055_SetDigitalChannel%,O%(J%+1) 370 TIME=0:REPEAT UNTIL TIME>Delay% 380 SYS K8055_ClearDigitalChannel%,O%(J%) 390 SYS K8055_ClearDigitalChannel%,O%(J%+1) 400 NEXT 410 NEXT 420 430 SYS K8055_ClearAllAnalog% 440 SYS K8055_OutputAnalogChannel%,1,255 450 FOR I%=1 TO 3 460 FOR J%=1 TO 8 470 SYS K8055_SetDigitalChannel%,O%(J%) 480 SYS K8055_SetDigitalChannel%,O%(J%+1) 490 TIME=0:REPEAT UNTIL TIME>Delay% 500 SYS K8055_ClearDigitalChannel%,O%(J%) 510 SYS K8055_ClearDigitalChannel%,O%(J%+1) 520 NEXT 530 NEXT 540 SYS K8055_ClearAllAnalog% 550 SYS K8055_OutputAnalogChannel%,1,255 560 SYS K8055_OutputAnalogChannel%,2,255 570 580 FOR I%=1 TO 3 590 FOR J%=1 TO 8 600 SYS K8055_SetDigitalChannel%,O%(J%) 610 SYS K8055_SetDigitalChannel%,O%(J%+1) 620 TIME=0:REPEAT UNTIL TIME>Delay% 630 SYS K8055_ClearDigitalChannel%,O%(J%) 640 SYS K8055_ClearDigitalChannel%,O%(J%+1) 650 NEXT 660 NEXT 670 680 SYS K8055_ClearAllAnalog% 690 SYS K8055_OutputAnalogChannel%,1,255 700 SYS K8055_OutputAnalogChannel%,2,255 710 FOR I%=1 TO 3 720 FOR J%=8 TO 1 STEP-1 730 SYS K8055_SetDigitalChannel%,O%(J%) 740 SYS K8055_SetDigitalChannel%,O%(J%+1) 750 TIME=0:REPEAT UNTIL TIME>Delay% 760 SYS K8055_ClearDigitalChannel%,O%(J%) 770 SYS K8055_ClearDigitalChannel%,O%(J%+1) 780 NEXT 790 NEXT 800 810 SYS K8055_ClearAllAnalog% 820 SYS K8055_OutputAnalogChannel%,1,255 830 FOR I%=1 TO 3 840 FOR J%=8 TO 1 STEP -1 850 SYS K8055_SetDigitalChannel%,O%(J%) 860 SYS K8055_SetDigitalChannel%,O%(J%+1) 870 TIME=0:REPEAT UNTIL TIME>Delay% 880 SYS K8055_ClearDigitalChannel%,O%(J%) 890 SYS K8055_ClearDigitalChannel%,O%(J%+1) 900 NEXT 910 NEXT 920 930 SYS K8055_ClearAllAnalog% 940 SYS K8055_OutputAnalogChannel%,2,255 950 FOR I%=1 TO 3 960 FOR J%=8 TO 1 STEP-1 970 SYS K8055_SetDigitalChannel%,O%(J%) 980 SYS K8055_SetDigitalChannel%,O%(J%+1) 990 TIME=0:REPEAT UNTIL TIME>Delay% 1000 SYS K8055_ClearDigitalChannel%,O%(J%) 1010 SYS K8055_ClearDigitalChannel%,O%(J%+1) 1020 NEXT 1030 NEXT 1040 SYS K8055_ClearAllAnalog% 1050 SYS K8055_ClearAllDigital% 1060 ENDPROC 1070 1080 1090 DEFPROCsay_hello 1100 REM LEDs go from dark to bright three times in each colour 1110 1120 SYS K8055_ClearAllAnalog% 1130 FOR J%=1 TO 3 1140 SYS K8055_WriteAllDigital%,255 1150 FOR I%=180 TO 255 1160 SYS K8055_OutputAnalogChannel%,1,I% 1170 SYS K8055_OutputAnalogChannel%,2,I% 1180 NEXT 1190 SYS K8055_ClearAllDigital% 1200 SYS K8055_ClearAllAnalog% 1210 NEXT 1220 1230 FOR J%=1 TO 3 1240 SYS K8055_WriteAllDigital%,255 1250 FOR I%=100 TO 255 1260 SYS K8055_OutputAnalogChannel%,2,I% 1270 NEXT 1280 SYS K8055_ClearAllDigital% 1290 SYS K8055_ClearAllAnalog% 1300 NEXT 1310 1320 FOR J%=1 TO 3 1330 SYS K8055_WriteAllDigital%,255 1340 FOR I%=100 TO 255 1350 SYS K8055_OutputAnalogChannel%,1,I% 1360 NEXT 1370 SYS K8055_ClearAllDigital% 1380 SYS K8055_ClearAllAnalog% 1390 NEXT 1400 ENDPROC 1410 1420 1430 DEFPROCfadeout 1440 SYS K8055_OutputAnalogChannel%,2,255 1450 FOR J%=1 TO 8 1460 SYS K8055_SetDigitalChannel%,O%(J%) 1470 TIME=0:REPEAT UNTIL TIME>Delay% 1480 NEXT 1490 FOR J%=255 TO 180 STEP-1 1500 SYS K8055_OutputAnalogChannel%,2,J% 1510 TIME=0:REPEAT UNTIL TIME>5 1520 NEXT 1530 PRINT"The END" 1540 SYS K8055_ClearAllDigital% 1550 SYS K8055_ClearAllAnalog% 1560 ENDPROC 1570 1580 1590 DEFPROCswap 1600 FOR I%=1 TO 4 1610 FOR J%=1 TO 8 1620 IF J%=1 OR J%=4 OR J%=7 SYS K8055_OutputAnalogChannel%,1,255 1630 IF J%=2 OR J%=5 OR J%=8 SYS K8055_OutputAnalogChannel%,2,255 1640 IF J%=3 OR J%=6 SYS K8055_OutputAnalogChannel%,1,255: SYS K8055_OutputAnalogChannel%,2,255 1650 SYS K8055_SetDigitalChannel%,O%(J%) 1660 TIME = 0: REPEAT UNTIL TIME >Delay%*2 1670 SYS K8055_ClearAllDigital% 1680 SYS K8055_ClearAllAnalog% 1690 NEXT 1700 NEXT 1710 ENDPROC 1720 1730 1740 DEFPROCinit 1750 Board%=0 1760 Delay%=7 1770 1780 DIM O%(9) 1790 O%(1)=1 1800 O%(2)=2 1810 O%(3)=3 1820 O%(4)=4 1830 O%(5)=5 1840 O%(6)=6 1850 O%(7)=8 1860 O%(8)=7 1870 O%(9)=1 1880 1890 DIM T%(8) 1900 T%(1)=3 1910 T%(2)=2 1920 T%(3)=1 1930 T%(4)=8 1940 T%(5)=7 1950 T%(6)=6 1960 T%(7)=5 1970 T%(8)=4 1980 1990 DIM S%(9) 2000 S%(1)= 3 2010 S%(2)= 4 2020 S%(3)= 5 2030 S%(4)= 6 2040 S%(5)= 3 2050 S%(6)= 2 2060 S%(7)= 1 2070 S%(8)= 8 2080 S%(9)= 7 2090 2100 ENDPROC 2110 2120 2130 DEFPROCK8055_init 2140 REM Typing errors in routine name do not generate an error message - they just hang up the program. 2150 SYS"LoadLibrary","K8055D.dll" TO K8055_Board% 2160 SYS"GetProcAddress",K8055_Board%,"OpenDevice" TO K8055_OpenDevice% 2170 SYS"GetProcAddress",K8055_Board%,"ReadAnalogChannel" TO K8055_ReadAnalogue% 2180 SYS"GetProcAddress",K8055_Board%,"SetAllDigital" TO K8055_SetAllDigital% 2190 SYS"GetProcAddress",K8055_Board%,"CloseDevice" TO K8055_CloseDevice% 2200 SYS"GetProcAddress",K8055_Board%,"ClearAllDigital" TO K8055_ClearAllDigital% 2210 SYS"GetProcAddress",K8055_Board%,"ClearDigitalChannel" TO K8055_ClearDigitalChannel% 2220 SYS"GetProcAddress",K8055_Board%,"SetDigitalChannel" TO K8055_SetDigitalChannel% 2230 SYS"GetProcAddress",K8055_Board%,"OutputAnalogChannel" TO K8055_OutputAnalogChannel% 2240 SYS"GetProcAddress",K8055_Board%,"ClearAnalogChannel" TO K8055_ClearAnalogChannel% 2250 SYS"GetProcAddress",K8055_Board%,"ClearAllAnalog" TO K8055_ClearAllAnalog% 2260 SYS"GetProcAddress",K8055_Board%,"WriteAllDigital" TO K8055_WriteAllDigital% 2270 ENDPROC

A three colour LED show

Below is the circuit diagram and a suggested PCB layout.

The program

The program is written in the form of a short demo, which runs through various colour patterns and finishes with a slow fade-out. The LED to be lit is selected with the statement:

SYS K8055_SetDigitalChannel%,O%(J%)

Where O% is an array that holds the place value of the LED. This is needed because the LEDs are not connected in the right sequence. The different colours are selected by the statement:

N% is the channel number. When this is 1, the red LED is selected, when it is 2, the green LED lights up. To get the orange colour, both LEDs must be lit: Like this:

I% is a number between 0 and 255 which selects the output voltage of the DAC - 255=5V. To fade the LEDs this number can be slowly changed from 255 to a lower value. Like this:

As usual I supply a zip archive with the BBC BASIC for Windows program file and a stand-alone exec file

K8055_LED-3col.zip

There is also a

YouTube video of the project

And here are the two files for the K8061

K8061_LED-3col.zip

Return to the interfacing index

Back to the Limavady home page

A three colour LED show

Below is the circuit diagram and a suggested PCB layout.

The program The program is written in the form of a short demo, which runs through various colour patterns and finishes with a slow fade-out. The LED to be lit is selected with the statement:

SYS K8055_SetDigitalChannel%,O%(J%)

Where O% is an array that holds the place value of the LED. This is needed because the LEDs are not connected in the right sequence. The different colours are selected by the statement:

N% is the channel number. When this is 1, the red LED is selected, when it is 2, the green LED lights up. To get the orange colour, both LEDs must be lit: Like this:

I% is a number between 0 and 255 which selects the output voltage of the DAC - 255=5V. To fade the LEDs this number can be slowly changed from 255 to a lower value. Like this:

As usual I supply a zip archive with the BBC BASIC for Windows program file and a stand-alone exec file

K8055_LED-3col.zip

There is also a

YouTube video of the project

And here are the two files for the K8061

K8061_LED-3col.zip

Return to the interfacing index

Back to the Limavady home page

The program

The program is written in the form of a short demo, which runs through various colour patterns and finishes with a slow fade-out. The LED to be lit is selected with the statement: