C
A synchronous Serial Communication bus.
SCL - Serial Clock Line SDA - Serial Data Line
Connect slaves to master. SCL is the clock to tell when the slaves should send the data.
Low pin count, very easy
- What is I2C, Basics for Beginners - YouTube
- How I2C Communication Works and How To Use It with Arduino - YouTube
This is a LCD adapter, that converts i2c signals to analog signals.
Question
You can also have the concept of a clock. And you need to simultaneously read across multiple data lines.
- In this adapter, the “E” pin is the enable pin which tells the LCD to read the data from the bus.
Why isn't parallel the default?
Serial allows for higher clock speed.
- Parallel comm, sure you can have higher throughput with more data lines, but you are limited by the clock speed.
- At higher speeds, synchronization between multiple lines becomes a challenge due to clock skew (tiny timing differences between wires), signal reflections, and crosstalk between lines.
In many ways, these issues are somewhat analogous to CPU vs. GPU discussion.