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Gadget Freak Case #157: Microcontroller Lock Hardware Protects Bill's Sock Drawer

Gadget Freak Case #157: Microcontroller Lock Hardware Protects Bill's Sock Drawer

William Grill doesn't like people messing up his sock drawer, so he added an electronic lock that requires a user-defined sequence of key codes from three pushbuttons. The correct sequence opens the lock and turns on a status light. Enter the wrong sequence and an alarm circuit socks it to you with a noisy buzzer, flashing LED, or both. The designs use a Microchip Technology PIC12F509 microcontroller. Who knows what's in store for William's tie rack?


Gadget Freak Case 157 Microcontroller Lock Hardware Protects Bill's Sock Drawer


Amt Part Description Allied Part #
1 IC1-Microchip PIC12F509 MCU (8-pin DIP) 383-0284
1 Solenoid 804-0116
1 10I.25F Capacitor (50V DC) 613-0936
1 2.2I.25F Capacitor (50V DC) 613-0710
1 L3-LED, Green 505-2101
2 L1, L2-LED Red 505-2117
1 ASLM1-Mallory Sonalert 854-0034
2 Q1, Q2-IRLD024 Power MOSFET, N Channel 503-0515
1 820I(C) Resistor (1/8W) 840-0092
2 10KI(C) Resistor (1/8W) 840-0043
1 100I(C) Resistor (1/8W) 840-0076
1 330I(C) Resistor (1/8W) 840-0028
1 L78L05ACZ Voltage Regulator 248-0683
2 D1, D2-1N4148 Diode 431-0614
2* D3, D4-11DQ05 Schottky Diode 503-0046
3 K1,K2,K3-Pushbutton Switch 676-0219
1 AZ943-1AH-5DE Relay, %V DC Coil 686-0175
1 8-Pin DIP Socket 374-4541
2 3-Contact Terminal Block 742-0083
1 Battery Holder (3 AAA) 839-2484
3 Battery, AAA. Alkaline 729-4092
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