[Farlei Heinen] has a C programming class at school. Not wanting to do another boring cookie-cutter project out of the textbook, he decided to do something different — he’s built an Arduino controlled sentry gun!
It consists of two parts: The sentry gun itself and a sonar detection tower which can tell if you’ve successfully knocked down the pigs or not. He’s using an Arduino Mega at the heart of the project, which controls the servos and reads information off of the sonar sensors.
The sentry gun uses two servo motors to control up and down, and left and right. The loading mechanism is manual, using elastic bands to launch the projectile. The firing mechanism however is a micro (9g) servo, which can release the elastic and shoot the projectile. The target is an Angry Birds toy play set made for kids.
It’s a pretty cool project, and [Farlei] has even released the source code for it if you’re interested in building your own — check it out in action, after the break!




The 12AU7 is popular due to its ruggedness and tolerance for low operational voltages. This amp design uses a plate voltage of 12, although the 12AU7 can handle up to about 330. Since the 12AU7 is of the Twin Triode variety, one tube can be used to amplify both a left and right audio channel.


