The Arduino Eye Shield is a circuit board that can be plugged on top of the Arduino allowing it to interpret analogue video ( PAL or NTSC ) from a camera or other source. It gives the Arduino the power of sight. There are many applications for this. In the example below the video information from the camera is used to drive an 8x8 LED matrix (with
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a MAX7219 and the Arduino Matrix library ). The PAL and NTSC formats have a relatively straightforward structure. For each line we see a negative-going pulse, then a colour burst, followed by the picture information - where the brightness is determined by the voltage of the signal. Lines follow sequentially to make up a full picture, with additional synchronisation pulses to indicate a new frame. In the example below we see two lines (and the pulse and sync of the next), where there will be two darker vertical features against a brighter background. For a more complete description see: PAL video timing specification. In the circuit below the LM1881 (IC1) separates the synchronisation pulses from the video signal, allowing the Arduino to identify a specify line of the picture. To read the information we need to sample the changing voltage along the line, which for PAL takes 52uS. The Arduino`s AnalogRead is too slow (taking about 100uS per sample). The solution used here is to digitise the video signal using a simple comparator circuit, which can then be read by a DigitalRead operation that takes about 4uS, allowing for operations to store the read value, this allows at least 8 samples to be made per line for the picture. The comparator ( AD811, IC3) sets its output either high or depending on whether the video signal is above or below the reference level. The reference-level is set dynamically by the Arduino. To obtain...
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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