User manual

PoStep60 user manual
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8 PoStep60 I2C protocol specification
PoStep60 has implemented I2C communication connection which enables setup and read most of
the driver configuration parameters and statuses. I2C pins are located on PoExtension connector
(please see Figure 1).
Pin
Function
1
5V
2
GND
5
SCL – I2C clock pin
6
SDA – I2C data pin
3, 4, 7, 8, 9, 10
NC – not connected
8.1 I2C address
PoStep60 default I2C address is set to 1 (0x01), but can be configured within PoStep60 application to
any value between 1 and 127 (please see Figure 18). This way multiple PoStep60 drivers can be
connected to same I2C bus and be monitored and configured externally in real-time. To confirm the
I2C address “Write values to driver” has to be clicked.
Figure 18: PoStep60 I2C address setup
8.2 PoStep60 I2C protocol
I2C communication is driven by a single I2C master which communicates to multiple slaves (PoStep60
drivers). Every packet consist of I2C address, Read/Write command bit, command byte (in case of
write) and multiple data bytes. In write operation master specifies command for either write or read
operation. In a Master read operation, based on previously written command, data bytes are sent
back from PoStep60 driver (slave). Always applies the last command send by the master.
8.2.1 Master write
In Master write operation master always provide a command as a first data byte. Following bytes
represent data to be interpreted by PoStep driver.
STOP
I2C ADDRESS
R/W=0
A
COMMAND
A
BYTE0
A
…
BYTEn
A
END
From Master to PoStep driver
From PoStep driver to Master
NOTE!
In a Master read operation always applies the last command send by the master in a
Master write operation. This way same parameter can be read continuously.
1: I2C address
2
1
4
3
6
5
8
7
10
9