.. include:: <isonum.txt>

Sensor Glossary
===============

Sensors are used in a variety of applications within FTC\ |reg|. 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 <https://andymark.com/products/ma3-absolute-encoder-with-cable>`_)
      - Potentiometer (`REV-31-1155 <https://www.revrobotics.com/rev-31-1155/>`_)
   - Relative
      - REV Through Bore Encoder (`REV-11-1271 <https://www.revrobotics.com/rev-11-1271/>`_). It has absolute support but over PWM, which is inaccessible within the FTC control system.
      - E4T (`am-3132 <https://andymark.com/products/e4t-oem-miniature-optical-encoder-kit>`_)
      - Generic (`Sparkfun Rotary Encoder <https://www.sparkfun.com/products/9117>`_)
- Positional
   - Linear Potentiometers Slide Pot (`Sparkfun Slide Pot <https://www.sparkfun.com/products/9119>`_)

Contact
-------

- Physical
   - Limit Switches (`3103-0001-0001/3103-0001-0002 <https://www.gobilda.com/limit-switches/>`_)
   - Endstops Generic (`Sparkfun <https://www.sparkfun.com/products/13014>`_)
   - Touch Sensor REV (`REV-31-1425 <https://www.revrobotics.com/rev-31-1425/>`_)
- Magnetic
   - Hall Effect Sensor REV (`REV-31-1462 <https://www.revrobotics.com/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 <https://www.revrobotics.com/rev-31-1389/>`_, that convert the sensor data to be readable by the REV hubs. The `REV Expansion Hub guide <https://docs.revrobotics.com/duo-control/sensors/5v-sensors#logic-level-converter>`_ 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.