What Is...I2C?

Summary

The video script introduces I2C (Inter-Integrated Circuit), a serial communication protocol developed by Philips in 1982 for connecting peripheral devices to microcontrollers. It's known for its simplicity, requiring only two pins, and is cost-effective due to fewer logic gates needed. I2C is widely used in various applications like IoT, consumer electronics, and aerospace. The protocol operates synchronously with a master-slave model, allowing bi-directional communication. It offers different speed modes, with standard, fast, and fast mode plus being the most common. The script also explains the I2C communication process, including start and stop conditions, slave addressing, read/write bits, and data transfer.

Takeaways

• 🌐 I2C (Inter-Integrated Circuit) is a communication protocol for connecting peripheral devices to a microcontroller.
• 📅 I2C was developed by Philips (now NXP) in 1982 for serial communication between integrated circuits.
• 🔗 I2C is widely used in various applications including IoT, consumer electronics, industrial equipment, automotive, and aerospace.
• 💰 I2C devices are cost-effective due to fewer logic gates required and only needing 2 pins for implementation.
• 🔄 I2C operates on a master-slave architecture with the master device providing the clock signal for communication.
• 🚦 I2C is a synchronous, bi-directional, and serial bus protocol.
• 🔢 I2C supports five speed categories ranging from 100 kHz to 5 MHz, with standard mode, fast mode, and fast mode plus being the most common.
• 🔗 Each device on an I2C bus must have a unique slave address, which is specified in the device datasheet.
• 🔵 The I2C protocol involves a start condition, slave address, read/write bit, acknowledge bits, data bytes, and a stop condition.
• ⏲️ I2C transactions are initiated with a start condition where the master pulls the SDA line low while SCL is high.
• 🔔 Acknowledge bits in I2C act as a 'handshake' between the master and slave, ensuring correct data transmission.

Q & A

What does I2C stand for?

I2C stands for Inter-Integrated Circuit, which is also referred to as I2C or IC.

Who created the I2C protocol?

The I2C protocol was created by Philips, now NXP, back in 1982.

What was the original purpose of the I2C protocol?

The original purpose of I2C was to provide a simple serial bus for various TTL integrated circuits or ICs.

Why is I2C still widely used today?

I2C is widely used today because it is cost-effective to manufacture due to fewer logic gates needed and only requires two pins to implement.

What are the advantages of using I2C over other protocols?

I2C offers advantages such as lower costs, simplicity, and the fact that it only requires two pins, making it suitable for a wide range of applications.

What is the nature of communication in I2C?

I2C is a synchronous protocol with master-slave communication, where the master provides the clock and initiates communication with the slave.

What are the different speed categories in I2C?

The speed categories in I2C are Standard Mode (100 kHz), Fast Mode (400 kHz), Fast Mode Plus (1 MHz), High Speed Mode (3.4 MHz), and Ultra Fast Mode (5 MHz).

What is the most common I2C speed category?

The most common I2C speed categories are Standard Mode, Fast Mode, and Fast Mode Plus due to their ease of implementation.

What are the two bus lines in I2C?

The two bus lines in I2C are Serial Clock (SCL) and Serial Data (SDA).

How does the I2C protocol ensure proper communication?

I2C protocol ensures proper communication by using pull-up resistors (R1 and R2), which work on the premise that SCL and SDA bus lines are open drain or open collector.

What is the purpose of the start and stop conditions in I2C?

The start condition initiates an I2C transaction by driving the SDA line low while SCL is high, and the stop condition terminates the transaction by releasing the SDA line while SCL is high, returning the bus to an idle state.

What does the R/W bit signify in I2C communication?

The R/W bit, following the slave address, indicates whether the master wants to read (1) from the slave or write (0) to the slave.

What is the function of the acknowledge bits in I2C?

Acknowledge bits in I2C serve as a 'handshake' between the master and the slave, indicating whether data was received correctly (ACK) or not acknowledged (NACK).