The electrical lines
The I2C bus lines are reported in the following table:
Name |
Description |
---|---|
SCL (Serial Clock) |
This is the bus clock signal |
SDA (Serial Data) |
This is the bus data signal |
GND |
This is the common ground |
I haven't reported the interrupt line since, strictly speaking, it's not part of the I2C protocol. It is usually implemented as a dedicated interrupt line connected to a CPU's interrupt capable pin (GPIO lines).
The GND line has been added because it's needed for electrical reasons, as the I2C protocol just talks about the SCL and SDA signals only.
In case of multiple devices are connected, the I2C devices can be connected in parallel, as shown in the following diagram:
Tip
The pull-up resistances Rp can be omitted in most cases, as most of the times an I2C controller integrates them by default.