I2C and sensors

[artemis1992]

Posted on March 19, 2014 at 16:08

Hello, I have a STM32F100RBT6B board, and I should use some sensors

LSM303D

with I2C

.

Just a question: wich is the maximum number of sensors that I can use with an I2C interface?

#sensor #i2c

[Tesla DeLorean]

Posted on March 19, 2014 at 16:18

wich is the maximum number of sensors that I can use with an I2C interface?

Will be limited by the number of unique addresses you can assign to the devices you plan on using, in the case of the part you mentioned that would be TWO, controlled by the SA0 pin

[artemis1992]

Posted on March 19, 2014 at 16:23

Thanks for the answer. So if I would like to control 4 sensors, should I use both I2C interface? In this case, is it impossible to control 5 sensor?

[frankmeyer9]

Posted on March 19, 2014 at 16:46

So if I would like to control 4 sensors, ...

 

Not correct.

I2C uses the LSB to differ between read and write access, so you can attach only two devices to one bus without interference.

That is even described in the LSM303D datasheet (see sect. 6.1.1).

[artemis1992]

Posted on March 19, 2014 at 17:00

Thank you very much

[artemis1992]

Posted on March 19, 2014 at 17:06

Thank you very much