All of our ultrasonic rangefinders will measure distance by tracking the time-of-flight of a sound wave. The diagram below shows how the sensor sends and receives the sound waves. Once the sensor emits a sound wave, it tracks how long it takes for the sound to reflect off of a surface and travel back to the sensor. The sensor then uses the known speed-of-sound to turn the time-of-flight into a range reading.

Our sensors can easily be connected and powered by the analog inputs on your NI roboRIO. If you use multiple sensors, you will have to connect the freerun/stop pin of the sensor to a digital output on the NI roboRIO. It is recommended to only have one sensor ranging at a time to avoid acoustic interfence, and the freerun/stop pin will allow you to control this. In our examples, the Analog Output (Pin 3) is the pin where you read the range value reported from the sensor.
The sensor pinout is shown below. The square pad with a hole is Pin 1.

Connect these pins to an Analog Input port on your RoboRIO. Our example uses Analog Port 0. That's all we need to do to connect our Sensor to the RoboRIO.

> Sensor Pin 3 connected to S
> Sensor Pin 6 connected to 5V
> Sensor Pin 7 connected to ⏚

Our sensors communicate with your RoboRIO using one of three methods:

• Analog Voltage Output (Pin 3) (example shown above)
• Pulse Width Output (Pin 2)
• 5 Volt RS-232 Serial Output (Pin 5)

In this example, we will use the Analog Voltage output for simplicity.
When power is applied to Pins 6 and 7 of our sensor, the voltage on pin 3 will change according to the distance between the sensor and the object in front of it. We can then use the RoboRIO to measure the voltage on Pin 3. This can be done using the WPILib Analog Input Library.