- on Home & Garden
- Published in issue 7/2013 on page 62
Acoustic Spirit Level / Tilt Alarm
An ATtiny45 design with many uses

This little project was inspired by a tilt sensor circuit which first appeared in our 2010 Special Projects Edition. The idea was to build a simple multi functional tilt sensor. The resultant design has two main uses; it functions as an acoustic three-axis spirit level or a security movement detector.
- www.elektor.com/070829
- www.atmel.com/devices/ATTINY45.aspx
- www.elektor.com/120633
- www.freescale.com/webapp/sps/site/taxonomy.jsp?nodeId=01126911184209#2
COMPONENT LIST
Resistors
R1,R3,R5 = 470kOhm
R2,R4,R6 = 330kOhm
R7 = 100Ohm
R8 = 220Ohm
Capacitors
C1,C3,C4,C5 = 100nF
C2 = 1µF
Semiconductors
IC1 = ATtiny45, programmed, Elektor # 120633-41 [3]
IC2 = LP2950 CZ3,3
D1 = LED, red
Miscellaneous
MOD1 = module with MMA7260QT tilt sensor installed (Elektor # 090645-91, limited to stocks)
Bz1 = piezo transducer (not a buzzer)
S1 = pushbutton with make contact
S2 = on/off switch
K1 = 2-pin PCB screw terminal block, 5mm pitch
Resistors
R1,R3,R5 = 470kOhm
R2,R4,R6 = 330kOhm
R7 = 100Ohm
R8 = 220Ohm
Capacitors
C1,C3,C4,C5 = 100nF
C2 = 1µF
Semiconductors
IC1 = ATtiny45, programmed, Elektor # 120633-41 [3]
IC2 = LP2950 CZ3,3
D1 = LED, red
Miscellaneous
MOD1 = module with MMA7260QT tilt sensor installed (Elektor # 090645-91, limited to stocks)
Bz1 = piezo transducer (not a buzzer)
S1 = pushbutton with make contact
S2 = on/off switch
K1 = 2-pin PCB screw terminal block, 5mm pitch