Article
Polyphonic Doorbell
Several tunes from a PIC 16F84
Music has been defined as ‘the art of combining sounds in a manner that is agreeable to the ear’. We thought would be a nice idea to entrust this delicate task to the best-known microcontroller in the Microchip stable, the PIC 16F84.This circuit, which can serve as a musical doorbell or music generator, is built around a microcontroller, and it can be configured by the user. You’ll be amazed by its virtuosity and the quality of the (polyphonic) sound it produces.As a doorbell, this circuit has several attractive features:– very good sound– eight different tunes– zero current when quiescent– customisable tunes– reasonable construction cost
Materials
Gerber file
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PCB
Component list
Resistors:
R1,R2,R3,R6 = 10k?
R4 = 470?
R5 = 1k?
R7-10 = 330?
R11-R22= 100k?
R23 = 1?
P1= 100k? logarithmic potentiometer
Capacitors:
C1,C2 = 22pF
C3 = 220µF 10V radial
C4 = 100nF
C5 = 1µF 10V radial
C6-C9 = 4µF7 10V radial
C10 = 22nF
C11,C12 = 22µF 10V radial
C13 = 220µF 10V radial
C14 = 220nF
C15= 100pF
Semiconductors:
D1 = zener diode 5V1 500mW
IC1 = PIC16F84A-10/P (programmed, order code 020354-41)
IC2 = TDA2006 (Philips)
T1 = BD240
T2 = BC547
Miscellaneous:
LS1= 4? loudspeaker
S1= pushbutton, 1 make contact
X1= 10MHz quartz crystal
9V battery (6F22) with clip-on leads
PCB available from the PCBShop
Disk, all project software, order code 020354-11 or Free Download
R1,R2,R3,R6 = 10k?
R4 = 470?
R5 = 1k?
R7-10 = 330?
R11-R22= 100k?
R23 = 1?
P1= 100k? logarithmic potentiometer
Capacitors:
C1,C2 = 22pF
C3 = 220µF 10V radial
C4 = 100nF
C5 = 1µF 10V radial
C6-C9 = 4µF7 10V radial
C10 = 22nF
C11,C12 = 22µF 10V radial
C13 = 220µF 10V radial
C14 = 220nF
C15= 100pF
Semiconductors:
D1 = zener diode 5V1 500mW
IC1 = PIC16F84A-10/P (programmed, order code 020354-41)
IC2 = TDA2006 (Philips)
T1 = BD240
T2 = BC547
Miscellaneous:
LS1= 4? loudspeaker
S1= pushbutton, 1 make contact
X1= 10MHz quartz crystal
9V battery (6F22) with clip-on leads
PCB available from the PCBShop
Disk, all project software, order code 020354-11 or Free Download
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