Justin Platz and Kurt Clothier from Pubnub illustrates how to control a physical object with the motion of two hands. They used Raspberry Pi and the Leap Motion controller for this purpose.
Controlling servos with hand motion
The two servos mirror the movement of the user’s two individual hands. Attached to the servos are 8×8 RGB LED Matrices, which react to each finger movement on your hand. The Leap Motion communicates directly with the Raspberry Pi via PubNub Data Streams with minimal latency, and the Raspberry Pi then drives the servos.
Leap Motion is a powerful device equipped with two monochromatic IR cameras and three infrared LEDs. In this project, the Leap Motion is just going to capture the pitch and yaw of the user’s hands and publish them to a channel via PubNub. Attributes like pitch, yaw and roll of hands are all pre-built into the Leap Motion SDK.
To recreate realtime mirroring, the Leap Motion publishes messages 20x a second with information about each of your hands and all of your fingers to PubNub. On the other end, our Raspberry Pi is subscribed to the same channel and parses these messages to control the servos and the lights.
Travershenry never felt like he had enough buttons on his joystick for flying games. So he designed his own game controller using Teensy to fulfill his need. It is a pretty neat design and works with any game that supports a joystick.
DIY game controller
Mihir Garimella is participating in the 2015 Hackaday Prize with his Firefly, an ARM Cortex processor powered low-cost flying robot with autonomous navigation.
Firefly changes this. Firefly is a low-cost (~$200), open-source flying robot platform for first responders. It includes a base layer of generic algorithms for completely autonomous flight—algorithms for avoiding obstacles and efficiently searching for targets—that are based on how organisms in nature solve the problems of perception and navigation. Users can plug in application-specific modules containing sensors (e.g., thermal cameras for finding people or gas sensors for finding fires or hazardous chemicals) that work with this algorithmic layer to autonomously accomplish different tasks.
ThomasVDD‘s DIY capacitance meter uses a 555 timer circuit as a monostable multivibrator, where the output pulse interval depends upon the value of the capacitance to me measured. An ATTiny84 is used to measure the duration of the 555 timer output pulse, and thus compute the capacitance, which is then displayed on a seven segment LED display module.
A while ago I also posted a tutorial on how to measure capacitance with a PIC microcontroller.
Digital capacitance meter
This cellphone-controlled toy car is controlled over a phone line by sending DTMF tones from another cell or landline phone.
Cell-phone controlled car
This Project implements the functionality of IVRS (Interactive Voice Response System) technology.
The car is controlled by a Mobile phone that makes a call to the phone attached to the Car. During the call, if any key is pressed, a DTMF (Dual Tone Multi Frequency) tone corresponding to the key is sent at the other end.
The received tone is processed by the Atmega16 microcontroller with the help of MT8870 DTMF decoder.
The decoder converts the tone into an equivalent binary code before sending it to the controller. The controller is pre-programmed to take a decision for any input and, outputs its decision to the motor driver that drives the car in various directions.