Room door automated keylock

Any type of keylock on the door usually is signaling that this area is more or less private and not everyone is welcome without permission. Outside doors usually have more serious locks installed, but if you need to add entry control to your room you may go with simpler solution – keypad operated door lock. Simplest solution requires an Arduino, keypad and DC motor with belt pulley. Motor is controlled using H-bridge driver. When uses inputs correct code on keypad, motor unlocks door and keeps it open for 5 seconds and then locks again. The lock even has an audible output when lock king mechanism is activated. Speaker is also gonna be upgraded to knocking sensor in future. Other things like status LED and IR led for remote also may… Continue reading

Driving DC motor with L298 H-bridge controlled by PIC

In some embedded projects you need to use DC motors and there is always what driver IC to use. Chris offers to try L298HN motor driver IC. Chip is actually well known H-Bridge which allows to drive DC motor in both direction but also can variate it’s speed with PWM inputs. In this particular example project Motor driver IC is interfaced to PIC18F452 microcontroller. Microcontroller generates signals needed to drive motor to selected direction and speed. Only to integer variables need to be adjusted. Sample code is available for download. This might be a good resource for your next upcoming project. Continue reading