Add HC-SR04 ultrasonic sensors with an EZ-B to AR Parrot Drone v1/v2 for collision detection and avoidance
How to add the Drone Collision robot skill
- Load the most recent release of ARC (Get ARC).
- Press the Project tab from the top menu bar in ARC.
- Press Add Robot Skill from the button ribbon bar in ARC.
- Choose the Ultrasonic category tab.
- Press the Drone Collision icon to add the robot skill to your project.
Don't have a robot yet?
Follow the Getting Started Guide to build a robot and use the Drone Collision robot skill.
How to use the Drone Collision robot skill
Overview (Beginner Friendly)
The ARC Drone Collision skill helps your drone detect objects (walls, furniture, people, etc.) by measuring distance with HC-SR04 Ultrasonic Ping Sensors. When something gets too close, the skill can alert you and/or trigger avoidance behavior (depending on your configuration).
This skill requires an EZ-B controller physically mounted on the drone to read the sensors. The drone itself (AR Parrot v1/v2) does not directly read HC-SR04 sensors, so the EZ-B acts as the “sensor hub” and sends the distance information into ARC.
What You Need
- Synthiam ARC installed on your PC
- AR Parrot Drone (v1 or v2)
- EZ-B controller (mounted to the drone)
- One or more HC-SR04 ultrasonic sensors (front is most common; optional: left/right/back/bottom)
- Wiring (jumpers) and a safe way to power the EZ-B and sensors while on the drone
Important Notes Before You Start
- You must mount the EZ-B on the drone. ARC cannot read the HC-SR04 sensors unless they are connected to an EZ-B.
- You must mount the sensors securely. Loose sensors can vibrate, point the wrong direction, or fall off during flight.
- This manual does not include physical mounting instructions. Every drone build is different (frames, weight, battery, center of gravity).
- Ultrasonic sensors have limitations. Soft fabric, angled surfaces, and thin objects can be harder to detect reliably.
How It Works (Simple Explanation)
- The HC-SR04 sends out a short ultrasonic “ping.”
- The echo returns after bouncing off an object.
- The EZ-B measures how long that echo took and converts it into a distance.
- The Drone Collision skill uses that distance to decide whether the drone is “too close” and should warn/avoid.
Typical Sensor Placement
Beginners usually start with one front-facing sensor for basic “don’t hit the wall” protection. You can expand later:
- Front: Detect obstacles ahead (most important).
- Left/Right: Helps when drifting sideways.
- Back: Useful for reverse movement.
- Bottom: Can help with basic height/ground proximity (use carefully).
Basic Setup Steps (High Level)
- Mount the EZ-B to the drone so it is secure and balanced.
- Mount the HC-SR04 so it points in the direction you want to detect (commonly forward).
- Wire the sensor to the EZ-B according to your EZ-B’s supported sensor wiring method.
- Add/connect the appropriate AR Parrot Drone control in ARC (for v1 or v2).
- Add/connect the EZ-B connection in ARC.
- Confirm ARC shows the EZ-B as connected before continuing.
- Add the Drone Collision skill from ARC’s Skill Store (or Add Skill menu).
- Select which EZ-B ports/pins your HC-SR04 sensor(s) are connected to.
- Set a safe distance threshold (the distance at which you want warnings/avoidance to occur).
- Test with the drone powered but not flying (props removed if possible for safety).
- Move your hand or an object in front of the sensor and verify the distance changes.
- Confirm the skill triggers the expected warnings/behavior at your threshold.
Calibration & Tuning Tips
- Start with one sensor (front) until it works reliably.
- Watch for false readings caused by vibration or angled surfaces; adjust mounting angle if needed.
- Increase the threshold if the drone reacts too late; decrease it if it reacts too early.
- Keep weight low. Extra hardware reduces flight time and affects stability.
Troubleshooting (Common Beginner Issues)
What We Don’t Provide
We do not provide specific instructions for mounting the EZ-B to your AR Parrot Drone or mounting the HC-SR04 sensors. These steps depend on your drone version, frame modifications, battery choice, and weight/balance requirements.
Quick Checklist
- EZ-B mounted securely
- Sensor(s) mounted firmly and aimed correctly
- Wires secured away from props
- ARC connected to drone control
- ARC connected to EZ-B
- Drone Collision skill configured to correct ports
- Threshold set and tested on the ground
Beginner Recommendation
Start with a single front sensor and basic warning/stop behavior. Once stable, expand to additional sensors for better coverage.
The goal is reliable sensing first, then avoidance tuning.
