Ultrasonic Sensor (HC-SR04) + Raspberry Pi

Hardware

• Raspberry pi 3
• Ultrasonic Sensor(s) - HC-SR04
• A set of resistors for each sensor you are connecting
  • 330Ω and 470Ω
• Jumper wires to connect the sensor(s) to the pi
• Breadboard to connect the sensor(s) to the pi

Wire setup

Pins

There are four pins (labeled) on the sensor that need to be connected to the pins on the Raspberry pi

1. VCC to Pin 2 (5v - power)
2. GND to Pin 6 (ground)
3. TRIG to Pin 12 (GPIO18)
4. The 330Ω resistor to ECHO

• - On its end, connect it to Pin 18 (GPIO24)

  - Through a 470Ω resistor, connect it also to Pin6 (ground).

  - This is done because GPIO pins only tolerate maximal 3.3V

Breadboard

Use the breadboard as a connection between the sensor and the pi as done in this circuit diagram

• An additional sensor can be connected to the pi by mirroring this exact set up on the other half of the breadboard
  • Connect the VCC and GND to the same pins (2 and 6)
  • Choose any two GPIO pins for the TRIG and the ECHO connection
    • Just be sure to account for the correct GPIO pins in your code

Connecting resistors and jumper wires between sensors and pi

Software

Python

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Create a new script

• Link to repository with script to detect the distance of an object in front of the sensor

Creating a new script in Python 3

Save your script as ultrasonic_distance.py

• Go to File and click on Save as
• In the field Save in browse for the C: drive and then select a folder to save in
• For the field File name type in ultrasonic_distance.py
• In the field Save as type select All Files
• Click on Save

Use the terminal to run the script

• Click on the monitor icon on the top of the screen
• Type cd "folder name" to change directory to your pythonpractice folder, and hit Enter
• Type ultrasonic_distance.py and hit Enter to run your program