Wk6 - Advanced Sensors Flashcards
What is the primary function of a sensor?
A sensor converts a physical phenomenon (e.g., temperature, mass) into an analog voltage signal, which is then digitized by an A/D converter.
What are the main limitations of simple sensors in IoT devices?
Simple sensors require a separate A/D converter for each sensor. A/D converters can be expensive, and IoT devices often cannot support dozens of digital input signals. This can make the device design complex and increase software complexity.
What is an advanced sensor, and how does it differ from a simple sensor?
Advanced sensors internally digitize the analog signal and may pre-condition the data, reducing wiring and simplifying the overall IoT design. They often use standardized communication protocols.
Why are advanced sensors beneficial in IoT systems?
They simplify wiring, reduce hardware complexity, and enable networking of multiple sensors, which makes scaling more practical and less costly.
What is an example of an advanced sensor, and how does it work?
The DHT20 temperature and humidity sensor is an advanced sensor. It provides data in user-friendly units through the I2C protocol, requiring no manual scaling or conversion.
What are three common protocols used to communicate with advanced sensors?
1-Wire: Single wire for data transfer, low speed (~16 kbits/sec)
I2C: = Inter Integrated Circuit, 2-wire interface, medium speed (~5Mbits/sec), used by sensors like DHT20
SPI: Serial Peripheral Interface, 4-wire interface, medium-high speed (~5Mbits+/sec)
What is the I2C protocol?
I2C, which stands for Inter-Integrated Circuit, is a protocol that was developed by Phillips. The I2C interface uses data and clock signals to transfer data between a sensor and a microcontroller.
What role do sensor networking protocols play in IoT systems?
Sensor networking protocols allow multiple sensors to communicate with the IoT device efficiently, enabling the system to support more sensors without complex wiring.
What are some benefits of networking sensors?
Networking sensors leads to:
- Less wiring to the IoT device.
- Support for more sensors on the IoT device.
What is a disadvantage of networking sensors?
Networking sensors increases software complexity, although libraries can help mitigate this issue.
What does the AHT20 library do?
The AHT20 library handles the I2C communication interface to the sensor. It also manages the I/O pin settings.
