Using LEDs as light sensors. A DDR pad. We designed our pad to have no moving parts. Instead, we chose to measure light reflectance off the user`s feet to determine if one of the arrows was being stepped on or not. Since a design with no moving parts offers little to no tactile feedback, we wanted to make sure the pad offered some other form of feedback, so the user would know when they
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had successfully stepped on the arrow. The design consists of one master controller and four slave controllers. Each slave controls a set of 15 LEDs. Thirteen LEDs are placed around the border of the arrow and flash in rhythm with the music. The remaining two LEDs are used as an illumination and sensing pair - the LED pointing straight up acts as a permanent flashlight, and the LED at an angle serves to sense reflection of the previous LED off the foot of the player. Readings are taken with the technique described in the MERL paper, summarized here. We place the interior sensing LED in reverse bias mode to allow the LED to charge up a capacitance in the LED junction itself. When a reading is to be taken, we set the cathode to input mode, disable the internal pull-up resistor, and time how long it takes the capacitance to discharge. Greater light input results in a shorter discharge time. As light from the illumination LED reflects off the foot of the player, the time the LED takes to discharge through the microcontroller decreases. By comparing this time to a threshold, the slaves determine if the arrow is pressed, and will raise or lower a line to the master accordingly. The master runs the main DDR pad controller program. It determines when the arrow LEDs should be on by and receives constant readings from the slaves. The master passes the readings from the slaves on to the Xbox 360 controller. The master can receive...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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