The reed switch is an electrical switch operated by an applied magnetic field. It consists of a pair of contacts on ferrous metal reeds in a hermetically sealed glass envelope. They are often used in alarm systems, on bicycles for wheel speed measurement and in many other devices. Here we will say few words about reed switch and show you very interesting video how they are made
ADJD-E622-QR999 is a high performance, small in size, cost effective light to voltage converting sensor. The sensor combines a photodiode array and three transimpedance amplifiers in a single monolithic CMOS IC solution. With a Red (R), Green (G) and Blue (B) color filters coated over the photodiode array, the sensor converts RGB light to analog voltage outputs, denoted by VROUT, VGOUT and VBOUT, respectively. Complete project with ATmega8 using this sensor can be read at THIS ARTICLE
In this project we used ADJD E622 QR999 light to voltage converting sensor to detect color of surface in front of our PCB board. This kind of sensors are often used in robotics and where color detection is needed. Complete source code and schematic with PCB design is provided below.
Light .Visible light is an electromagnetic wave in range of 400 to 700nm. This is just a small part of all existing wavelengths. The light that we see is not one wavelength but a combination of many wavelengths.
The spectral power distribution - SPD shows the precise dependence of the color in function of light source in the form of diagram that represents energy at each wavelength in the visible spectrum.