Internet of Things (IoT) is no longer a new concept and is now an everyday term. In fact, the IoT market has grown steadily in the past few decades and is expected to grow to 20 billion devices by 2020. IoT infrastructure is involved in many new applications and companies where physical and virtual devices can interact through data networks without human intervention. Examples of IoT applications are smart cities, smart homes, eHealth, smart transportation, critical infrastructure, precision agriculture, smart manufacturing or Industry 4.0. These applications are becoming increasingly diverse, complex and demanding.
So have you wondered about what are “Things” in the Internet of Things?
Things in the Internet of Things (IoT) are sensors or physical objects with a unique identifier, and embedded devices have the ability to transfer data across a network.
Using sensors must be as simple and smooth as connecting a mouse to a computer.
Plug and Play, sometimes abbreviated as PnP, is a catchy name for devices that work with computer systems as soon as they are connected.
What are Plug and Play I2C sensors?
Plug and Play I2C sensors communicate between an I2C Master device and a chain of I2C slave devices using I2C communications.
The Plug and Play sensor consists of two main components: conventional analog sensors and electronics that make the sensor easy to communicate using an I2C communication protocol.
The simple yet powerful difference between traditional analog sensors and plug-and-play sensors is that in these plug and play sensors the communication is done using the I2C communication protocol where one master device controls the multiple sensors connected in I2C chaining.
What is Plug and Play I2C interface?
Through the plug-and-play I2C interface, you can connect multiple I2C bus devices to each other and communicate individually with each device at high speed (subject to I2C restrictions). Plug-and-play I2C interface uses standard 4-pin I2C input and I2C output. Plug-and-play I2C devices transmit 5 V I2C data and supply 5 V current directly through this connection. Plug-and-play I2C devices use standard I2C communication for all data transmission, which is supported by almost every microcontroller produced today. The plug-and-play I2C interface is only the 5 V standard, which is ideal for longer cable transport. Plug-and-play I2C devices always contain a 6-inch (152 mm) 4-core I2C cable. The plug-and-play I2CM module always contains a 3″ (76mm)4-core I2C cable. Cables and connectors are available separately for designers who want to integrate their own plug-and-play I2C interface into their designs.
Benefits of Plug and Play Sensors
- No soldering required
- Easily expand your sensor network
- Easily connect master devices to multiple popular computing platforms
Raspberry Pi, Pi 2, Pi 3, Pi Zero, Pi 4
Arduino Uno, Nano, Micro, and Others
Particle Photon, Electron, Boron, Argon, and Xenon
- Use the Master Devices to Communicate to plug and play slaves(Nodes)
Relay Controllers & FET Controllers
Pulse Wide Modulators
GPIO Expansion Devices
4-20mA Input and Output Devices
0-10V ADC and DAC Expansion Devices
- Less jargon of wires.
- Plug and Play Uses Standard I²C Communications to communicate to All Expansions
- Connect Plug and play Nodes using USB or Wireless Communications
- Use Multiplexers to add more plug and play I²C Expansion Ports
How plug and play I²C Devices Connected?
Connecting plug-in and play devices is simple. Start by choosing the Master first. The Plug and Play Master adapts to the standard plug and play bus of your favorite computing platform.
Every plug and play device needs a different I2C address to operate properly in the I2C chain. It is important to note that some I2C devices have a fixed address while others have a limited range of addresses to customize their addresses.
Below is a partial list of some popular Plug and play Master devices that support Plug and play I2C communications. Click here for a complete list
Plug and Play compatibility
Plug-and-play I2C interface adapters are available for Arduino, Banana Pi, BeagleBone, Blues, ESP8266, Omega Onions, Photons and Electrons, PyCom, Raspberry Pi, 2, 3 and Zero and Windows. Plug-and-play I2C interface devices are compatible with almost everything in the microcontroller industry.
Different types of plug and Play I2C Extensions
You can connect a wide variety of plug and play devices to a master device using the Plug and Play master adaptor and 4-pin plug and play cable.
I2C Port 1 Pin 1: Carries the I2C SCL Signal to Pin 4 on an I2C sensor.
I2C Port 1 Pin 2: Carries the I2C SDA Signal to Pin 3 on an I2C sensor.
I2C Port 1 Pin 3: Carries +5 Volts to Pin 2 on an I2C sensor.
I2C Port 1 Pin 4: Carries Ground to Pin 1 on an I2C sensor.
Below is the partial list of a variety of Plug and Play devices(sensors). Click here for a complete list
LSM9DS0 3D Accelerometer Gyroscope Magnetometer I2C Mini ModuleLSM9DS0 3D Accelerometer Gyroscope Magnetometer I2C Mini Module
How many Plug and Play devices can be Chained Together?
Although I²C communication usually supports more than 100 devices, there are many factors that can limit the number of devices that can be connected in a plug and play I²C communication bus.
The four main factors are given below
- I2C addressing
- I2C communication speed
- Cable distance
- 5V I²C communication standard
- I2C Addressing: Unique I²C addressing is the main limiting factor in I²C communication protocol. Each I²C plug and play device has a fixed address or several jumpers that allow you to change the device address in a limited range. For example, a relay controller based on the MCP23008 has 3 jumpers that can be used to configure addresses that limit the maximum number of I²C devices to 8 per plug and play I²C port. Some I²C communication chips only allow 1 or 2 bus devices. More information about device addressing can be found on the datasheet.
- I2C communication speed: I²C communication speed also plays an important role in the total number of plug and play devices. In general, the slower speed is better if you connect multiple I²C devices using I2C cables. We can achieve very good results with a communication speed of 100 kHz I²C. Higher speeds, such as 400 kHz or more, tend to produce capacitive slewing on the I²C bus, that is not reliable over cables. One way to overcome the effects of signal slewing is to use a 4.7K I²C bus termination jumper, which is available on most I²C plug and play devices.
- Cable Distance: Cable Distance is yet another critical factor for I2C communications. In general, I2C devices have never been designed to operate over long cables. In general, I²C devices have never been designed to operate with long cables. However, immunity to interference from most I²C communication chips has allowed cable lengths of up to 30 meters. It is not recommended to use cables of this length. In general, keep the cable length as short as possible and test each device carefully before connecting other devices to the plug and play I²C bus. We have seen many reliable I²C connector cables in the range of 2 to 3 meters, but keep the cables as short as possible and check carefully.
- 5V I²C communication standard: The use of the 5V I²C communication bus is standard for plug-and-play devices. Because all power supplies and playback devices comply with the strict 5V standard. This allows longer cable lengths due to higher differential voltages between 0 and 5 V data signals. The disadvantage of using the 5 V standard is that it is NOT directly compatible with most CPUs because of an exceptional voltage standard of 3.3 V or less. For this reason, all plug-and-play master adapters convert the standard 3.3 V of the ordinary microprocessors into a 5 V I²C bus standard. This is important when working with I²C cable devices, especially if you use longer cables and higher speeds. Therefore, NEVER connect the plug and play I2C device directly to the 3.3 V microprocessor of your choice, WITHOUT a properly designed 5 V I²C level shifter in location, as this can cause damage.
Plug and Play I2C cables and connectors:
Plug and Play devices are connected using Plug and Play cables included with all related devices, controllers and sensors.
Expansion of Plug and Play devices using Multiplexers
A multiplexer is a device with Plug and Play I²C input and 4 or 8 Plug and Play I²C output ports. This effectively converts one Plug and Play I²C port into several Plug and Play I²C ports so that more devices can be controlled by branching. Some I²C devices may have a fixed address that limits the use of one device on the Plug and Play I2C port.