Sensor Glossary¶
Sensors are used in a variety of applications within FTC®. Sensors can give external feedback regarding the position of the robot (for example, relative to the field wall or to a vision target) or internal feedback (velocity, distance traveled, voltage, etc.). Sensors can also be used to determine the rotation of a mechanism and detect color.
Encoders/Potentiometers¶
- Rotational
- Absolute (+ Potentiometers)
MA3 (am-2899 )
Potentiometer (REV-31-1155 )
- Relative
REV Through Bore Encoder (REV-11-1271 ). It has absolute support but over PWM, which is inaccessible within the FTC control system.
E4T (am-3132 )
Generic (Sparkfun Rotary Encoder )
- Positional
Linear Potentiometers Slide Pot (Sparkfun Slide Pot )
Contact¶
- Physical
Limit Switches (3103-0001-0001/3103-0001-0002 )
Endstops Generic (Sparkfun )
Touch Sensor REV (REV-31-1425 )
- Magnetic
Hall Effect Sensor REV (REV-31-1462 )
Optical¶
- Color
Adafruit RGB
REV Color
MR Color
- Computer Vision
- Hardware
PixyCMU
- Software
OpenCV (EasyOpenCV)
Distance¶
ToF
Ultrasonic
Other¶
- IMU
Accelerometer
Gyroscope
Compass
Magnetometer
Logic Level Converter¶
The REV Robotics system runs on 3.3v sensor logic. Most off the shelf sensors used in FTC natively use/support 3.3v logic, but some sensors may not. To solve this, REV sells boards, called logic level converters , that convert the sensor data to be readable by the REV hubs. The REV Expansion Hub guide has a chart detailing what adapters are needed for what sensors.
It is ideal to not use logic level converters to simplify your wiring. If you need to, there is a best practice. Electrical tape the connectors on either end, this helps with static, and it keeps it from being physically disconnected. This does produce a very noticeable effect with encoders on fields with lots of static.
The second tip is to never tape over the middle or LED. The board generates a very small amount of heat, and it’s very easy to overheat if it can’t ventilate, also don’t fully enclose it in any cases without holes.