How it works?

The human retina has three cells types that are sensible to color, called cones. Each one is sensible to a specific wavelengths range of the light spectrum, more specifically to peaks in 419 nm (blue-violet), 531 nm (green) and 559 nm (green-yellow). The cones’ classification in “red”, “green” and “blue” (RGB) is a simplification used for convenience to represent the three target frequencies. All the existent colors are a combination of these three primary colors.

The device has three color sensors that recognizes the red, green and blue components. When the device turns on, two LEDs are lit to illuminate the object that will have your color recognized. Pressing one of the buttons (1), the sensors’ information are sent to the micro-controller (2). The micro-controller compares the received values with a color table and approximates it to one of the tabulated color. Once the color was identify, the correspondent sound is played in the speaker (3).

The money bills identification happens by a similar process. The money bills in Brazil has different colors that permits the use of this property to identify them. When the user pushes the button (1), the color sample is sent to micro-controller (2), it is verified which color is the nearest of this sample and which money bill has it and its value is played in the speaker (3).

Current Stage

We have a functional prototype that only speaks the color name or the money bill value when the device is connected to a computer with a specific installed software, developed by us. Currently the color name is showed in a LCD display too.

Source Code

The source code is open and it is available at GitHub.