Let's add to our room sensor - Part 5 - Movement detection

Summary

In this DIY Electronics tutorial, Pascal guides viewers through building an ESP-based motion sensor using a passive infrared (PIR) sensor. The project integrates with ESP Home to monitor movement and control lighting, distinguishing between movement and presence. The tutorial covers hardware setup, software requirements, and coding, with a focus on practical applications and future enhancements using millimeter wave sensors.

Takeaways

• 😀 The tutorial is about building an ESP-based motion sensor package using ESP Home.
• 🔍 The HC-SR501 PIR (Passive Infrared) sensor is recommended for its precision and reactivity in detecting motion.
• 🛠️ PIR sensors work by detecting changes in infrared radiation caused by body heat, commonly used in security and automatic lighting.
• 🔬 The difference between PIR and millimeter wave sensors is highlighted, with the latter providing more detailed presence detection.
• 💡 PIR sensors are cost-effective and simple for basic occupancy detection like motion-activated lighting.
• ⚙️ The HC-SR501 has settings for repeat trigger and single trigger modes, along with sensitivity and time delay adjustments.
• 🔩 The assembly process involves connecting the PIR sensor to specific GPIO pins on the ESP board, with safety measures taken to avoid damage.
• 📝 The code for the PIR sensor in ESP Home is simple and involves binary GPIO sensor states, with unique identifiers and device classes.
• 🔄 The tutorial includes practical demonstrations of the sensor's functionality, including triggering the sensor and observing its effects on a light.
• 🏠 Home Assistant integration is showcased, with the sensor's data feeding into Home Assistant for automation purposes.
• 🤖 Automation examples are provided, such as turning a light on when motion is detected and ensuring it only activates under certain light conditions.

Q & A

What is the main focus of the tutorial presented by Pascal?

The tutorial focuses on building an ESP-based motion sensor package using ESP Home, with the aim of monitoring movement to switch a light on and off using automation.

What is the difference between a passive infrared sensor (PIR) and a millimeter wave sensor in terms of occupancy detection?

A PIR sensor detects motion by measuring changes in infrared radiation caused by body heat and is cost-effective and simple for basic occupancy detection. A millimeter wave sensor, on the other hand, emits microwave pulses and analyzes the reflected signals to detect movement with more precision and can even detect the presence of a person when there is no movement.

Why would someone choose a PIR sensor over a millimeter wave sensor for a project?

One might choose a PIR sensor for its simplicity, cost-effectiveness, and quick response to significant changes in infrared radiation, making it suitable for applications like motion-activated lighting and security alarms.

What are the two states of a PIR sensor?

A PIR sensor has two states: it sends a high 5 volts signal when motion is detected and a low signal when motion is not detected.

What is the purpose of the repeat trigger and single trigger settings on a PIR sensor?

The repeat trigger setting allows the sensor to continuously detect motion and restart the delay timer with each motion, useful for tracking ongoing activity. The single trigger setting causes the sensor to trigger once and maintain the output state for a specified time, ignoring additional motion during this period.

How does the sensitivity potentiometer on a PIR sensor affect its performance?

The sensitivity potentiometer adjusts the range of detection. Turning it clockwise increases the range, while turning it anticlockwise decreases it.

What is the function of the time delay potentiometer on a PIR sensor?

The time delay potentiometer adjusts the duration for which the sensor maintains a high output signal after motion is detected. Increasing the setting with the potentiometer extends the delay, while decreasing it shortens the delay.

What are the three typical pin assignments for a PIR sensor?

The typical pin assignments for a PIR sensor are ground (GND), output/data (OUT or DATA), and VCC (power supply).

How does the tutorial demonstrate the integration of the PIR sensor with Home Assistant?

The tutorial demonstrates the integration by showing the sensor's data feed in Home Assistant, creating an automation that switches a light on when motion is detected, and using conditions to ensure the light only turns on under certain illuminance levels.

What is the purpose of the condition block in the automation created in the tutorial?

The condition block is used to ensure that the light only turns on when the illuminance level falls below a certain threshold, preventing the light from turning on in bright conditions where it might not be needed.

What is the next step in the tutorial series after adding the PIR sensor?

The next step in the tutorial series is to add a millimeter wave sensor for presence detection.