Low Speed comms protocol codes

[japrenticeuk]

This feels like a really dumb question but I am stumped.

The example for reading measurement byte 0 from Ultrasonic sensor in "Ultrasoninc Sensor I2C Protocol" defines the data to be sent as 0x02, 0x42, R + 0x03

What is the significance of "R"

TIA

John Prentice 

[SeaMan67]

The significance of "R" is restart condition of i2c protocol.

It's necesary to switch from writing to reading data from the device, the byte next the  "R" is the device address with the R/W bit value of '1'.

bye.