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Converting voltages from 3.3V to 5V

Wed Jul 04, 2012 10:30 am


I was looking for a simple way to convert the Raspberry Pi voltages form 3.3V to 5V for interfacing and came across the following.

4-Way Bi-directional Logic Level Converter

Would using one of these enable 4 of the lines to become bi-directional with buffering to sort out the current or have I missed something.

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Re: Converting voltages from 3.3V to 5V

Wed Jul 04, 2012 4:04 pm

Hi - I just ordered something similar for connecting the Flexel data aquisition module. The Flexel is I2C but designed for the Arduino which is 5v so I need to step it down as the PIs GPIO are not 5v tollerent. I think you can get away with jus using 2x BSS138 if the slave device is open collector but mine has integral pull-up resistors so need an arrangement with further resistors also. I think all such devices are much of a muchness and do this:


I'm not sure if the BSS138 solution is the best for you - I have seen other more complex solutions by googling 'logic level convert 3.3 5v I2c' etc... I tend to google via pictures and look for schematics - saves a lot of time.
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