A harp without strings i. e. IR sensor-receiver pairs function as strings in our device. The device senses when a string is being plucked (causes blockage of IR). Correspondingly, the particular sound is produced by Direct Digital Synthesis. We used 6 TSOP sensors to identify the blockage of infrared led`s. They then give digital output to microcontroller which
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processes data and gives 6-bit digital output to Digital to Analog converter(r-2r ladder). DAC converts the digital input to analog data which is then filtered and amplified to drive the speakers. The microcontroller is used to interpret the sensor data and output the stored waveforms at the frequency assigned to the plucked strings using an interrupt. Since we were somewhat familiar of sensors because of line follower competition, we knew that working with the photodiode sensors would be difficult as their alignment and low sensitivity were some of the major problems. So we found out TSOP sensors which gave excellent variation from 0. 0 to 4. 81 V. Then we worked with two sensors kept at a distance of 5 cm to test that one led is not interfering with another sensor. We used pipes to remove this problem. TSOP sensors require the IR LED to operate on a square wave of a particular frequency, which in this case was ~38kHz. We provided the required square wave form by a circuit using the 555 timer. We then used DAC0808 to convert the digital output of TSOP sensors into analog signal but it was not working as per our expectations so we designed our own DAC chip using r-2r ladder. We were then getting range from 0 to 4. 5 V. Now we wanted to amplify this signal without affecting previous circuit. For this purpose we used a buffer and an amplifier which then gave range between 0 to 8. 6 V. We then gave this output to speaker...
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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