Sensors
Note
As per Game Manual Part 1 a UVC Webcam is not considered a sensor.
Listed below are a couple examples of common robot sensors. This is not
intended to limit or extend in anyway the scope of sensors as established in
<RE12>. While the FIRST Tech Challenge SDK supports many sensors not all
are natively supported.
Examples
Distance Sensor (Ultrasonic)
MB1242
RCWL-1601
An Ultrasonic Distance Sensor is a device that is able to measure the distance between an object and the sensor. It does this by sending out a sound wave and measuring the time it takes for the wave to travel to the object and back. Using this and the speed of sound the distance can be calculated.
Distance Sensor (Optical)
REV-31-1505
An Optical Distance Sensor is a device that is able to measure the distance between an object and the sensor. It does this by sending out a light beam and measuring the time it takes for the beam to travel to the object and back. Using this time and the known speed of light the distance can be calculated. Be mindful the way the object in question interacts with light can change the accuracy of the distance measurement. A transparent object like field panels will often provide innacurate measurements.
Color Sensor
REV-31-1557
MR 45-2018
A color sensor is a digital output device that is able to measure the color of an object. Most color sensors require the object in question to be relatively close to the sensor.
Touch Sensor
REV-31-1425
A touch sensor is a digital output device that detects the activation of a button. This can be used as a limit switch, a way to limit the range of motion of a mechanism. Such a device would typically use the digital port.
Magnetic Limit Switch
REV-31-1462
A Magnetic Limit Switch is used to detect the presence of a magnet in near proximity. This is commonly used to limit the range of movement of a mechanism that would cause damage if it went beyond said limit. This is done by placing a magnet on said mechanism which would cause the Limit Switch to activate. It is important to note that as a digital device this will only send out a boolean output and not a range. For measureing the strength of a magnetic field take a look at a magnetometer.
IMU
NAV X2 Micro
BNO055
An Interial Measurement Unit (IMU) is sensor that is a combination of a Gyroscope, Accelerometer, and Magnetometer. A Gyroscope is device that reports the angular orientation of an object in 3 dimensions. An Accelerometer is a device that reports the acceleration of an object in 3 dimensions. Acceleration can be thought of as the rate of change of speed at any given instance. A Magnetometer is a device that measures the strength of magnetic fields in 3 axis. This can be used as a compass to gain the orientation of a robot relative to the poles of the Earth, an absolute measurement.
Potentiometer
REV-31-1155
50k Ohm Potentiometer
A Potentiometer is a device that changes the output voltage based upon the degree to which the adjuster is turned. It is often used as a form of measuring the absolute orientation of an axle. The manner in which the output voltage change is subject to change based on the Potentiometer that is used. Such a device is typically attatched via the analog port of the REV Hub.