How many I2C devices does a level translator support?

Hey all,

I am doing a project which involves having up to 6 sensors working at a time or individually, and a OLED I2C display to showcase the data from the sensors. Hence my question,

How many level translators do I need for my project? How many devices does a level translator support?

I suppose that the OLED display does not need a level translator and I could connect it directly to the MCU.

The sensors work with 1.8V

Most OLED displays work at 3.3V. If you use an Arduino 5V board, you better use a level shifter for the OLED as well.

One level shifter is enough for a 1.8V I2C bus. The level shifter requires the high-side-voltage (5V or 3.3V) and the low-side-voltage (1.8V). Sometimes they are called HV and LV. The most used level shifter is with mosfets, like the Adafruit level shifter. They say it will work down to 1.8V.

The number of devices depends on the length of the wires, the pullup resistors, the level shifters, and so on. The actual number of sensors does not matter a lot, as long as they have different I2C addresses.

Which sensor is it ? Can they select 6 different I2C addresses ? If not, you might need a I2C multiplexer or a trick with the address selector.