Contents
What is stop condition in I2C?
After a message has been completed, a STOP condition is sent. A single message can contain multiple Start conditions. The use of this so-called “repeated start” is common in I2C. A Stop condition ALWAYS denotes the END of a transmission. Even if it is issued in the middle of a transaction or in the middle of a byte.
How many slaves will handle I2C?
“You have a 7-bit address. That means you can address up to 127 slaves.” “The number of devices connected to the bus is only limited by the total allowed bus capacitance of 400 pF.”
What’s the name of the second start condition in I2C?
So you can do the write operation and instead of completing it with a stop condition on the bus you can follow with a second start condition and the latter half of the operation, terminating the whole thing with a stop condition only when you are done. This is called a “repeated start” condition and looks as follows (from the BME280 datasheet).
What should I do if my I2C transaction fails?
This means that typically you will need to disable the peripheral, change the pins to GPIO mode and bit-bang the clocks you need out of the port, after which you need to re-initialize the I2C peripheral and try the next transaction, and if this fails then rinse and repeat the process until you succeed.
What is the operation of the I2C bus?
The operation of the I2C bus is a read and write process between master and slave devices. There are mainly divided into 3 processes: Master device writes data to the slave device: The master device reads data from the slave device:
Are there any timeouts in the I2C protocol?
Since I2C is essentially transaction/packet based and it does not include timeouts in the specification (SMBUS does of course, but most slave sensors conform to I2C only) there is a real chance that you are going to reset your host processor (or bus master) in the middle of such a transaction.