I2C

=== buffers ===
https://www.nxp.com/docs/en/data-sheet/P82B96.pdf
P82B96 Voltage Range bidirectional datatransfer between an I2C bus 2 V to 15 V range. 
 
=== raspberry ===
circuitbasics i2c
gist.github LCD
OLED i2c module raspberry spy
ada_i2c github repo
=== maxbotix ===
http://www.maxbotix.com/articles/095.htm links to https://github.com/felias-fogg/SoftI2CMaster
https://variecose.wordpress.com/2011/09/24/i2c-rtc-ds1307-and-arduino/ Mega2560 has internal pullups on the sda, sdc lines.
https://github.com/sosandroid/FRAM_MB85RC_I2C
Category:I2c
Category:Microcontroller