5V tolerance of Micro Bit

[pmulvey]

What is the position on the tolerance of the MicroBit to 5V on the I/O pins. Specifically I am considering connecting the MicroBit to a LCD backpack using I2C where the backpack has pullup resistors to its 5V rail. The LCD needs 5V to operate correctly.

[shaoziyang]

micro:bit use nRF51822 microcontroller, supply voltage range is 1.8 to 3.6v, and VIO is 0 to 3.6V, so it can tolerance 5V.

[rhubarbdog]

I had success with the same set up. I just pulled sda and scl to 3volts and had no problems. I now own a bi directional level shifter to interface between my 3volt and 5volt equipment. Have you seen my i2c lcd driver for microbit it's available here https://github.com/rhubarbdog/microbit-LCD-driver

[pmulvey]

I thought that I read somewhere that inserting 330R resistors in series with the I2C lines to the LCD backpack could protect the protection diodes on the 3V3 uC. I am currently running a NodeMCU V3 with no resistors directly on to the LCD backpack I2C lines and nothing has died... so far.