A teams of students from Colorado State University have designed and built a PIC-based circuit to control the flight of a blimp. You can control it manually by remote or let the zeppelin find it’s own path to a specific destination that is designated by an infrared beacon.
The remote control has a 20×4 LCD display which shows the commands and a 12 key keypad from which you can control take off, land, forward, reverse and steering commands. The zeppelin also has an altitude controller with ultrasonic sensors. This makes it go higher if it detects the ground too close or go lower if it’s altitude increases too much.
The thrust is given by two motors, each set at the end of a horizontal bar. A servo motor controls the angle of this bar and thus the direction of the thrust. There are four IR sensors each placed in the four cardinal points. These sensors serve the autonomous flight mode. The IR sensors output a low pulse when it “sees” the beacon so the zeppelin will follow the direction of the sensor which gives out the most pulses. The beacon is made with 16 IR LEDs driven by two 555 circuits.
The altitude control is been taking care of by a PIC16F84 designated IC2 in the schematics, steering is done by a PIC16F88, IC3, and all communicate with the control center a PIC16F874, IC4. Thrust motors are driven by SN754410, IC5 in the schematics. In the remote control you will find a PIC16F877P who takes care of all the RC functions, reading the keypad, displaying characters on the LCD, sending audio message to speaker and sending serial commands to the zeppelin.