Today I finished my self designed I²C Hub with an integrated level shifter.
I2C Hub with two SRF08 ultrasonic sensors
As level shifter I used the “4-channel I2C-safe Bi-directional Logic Level Converter – BSS138” from adafruit. Now it is possible to connect to the hub four 3.3V I²C devices plus the Raspberry Pi as 3.3V device and five 5.0V I²C devices and the Raspberry Pi as master. For the first test I connectec two ultrasonic sensors SRF08 as shown in the picture below on the 5.0V side of the board.
I2C Hub with level shifter
The picture below shows the I²Cdetect command executed in the terminal window. Both connected SRF08 ultrasonic sensors where found on the bus.
I2C Hub Raspberry Pi i2c detect SRF08
The hub is perfect for my robot car I actual build. With the 3.3V on one side and 5.0V on the other side I am now able to use 5.0V devices as well on my Raspberry Pi which is initially a 3.3V device.
I2C Hub with two SRF08 ultrasonic sensors 2
I have a question: Can I make the connection by the ONE SRF08 and the R-PI 3? Or I need a logic level converter like that you used?
The Raspberry Pi is a 3.3V device. You need such a I2C level-shifter to connect a 5.0V device to the Raspberry Pi without damaging the Raspberry Pi.