User Manual

PoKeys user manual
54
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7.13. Peripheral communication protocols
I
2
C protocol
The I2C bus was designed by Philips in the early '80s to allow easy communication between
components which reside on the same circuit board. Philips Semiconductors migrated to NXP in
2006. The name I2C translates into "Inter IC". Sometimes the bus is called IIC or I²C bus.
PoKeys devices support communication with I
2
C slave devices, connected to the PoExtBus/PoNET
connector. As I
2
C, PoNET and PoExtBus use the same connector, PoExtBus, PoNET and I
2
C functions
are automatically switched by the PoKeys device.
Marking the pin closer to the edge of the PoKeys57CNC board as pin 1, the I
2
C devices should be
connected as follows:
Pin 1
Power supply 5V
Pin 2
Ground
Pin 3
Serial data
Pin 4
Pin 5
Serial clock
Protocol can be tested via PoKeys configuration software. Click on Peripherals > I2C bus test... The
following dialog appears.
Figure 28: I
2
C protocol test dialog