Half of all “my sensor doesn’t work” problems are I2C problems. These guides cover bus wiring and pull-ups, address scanning and conflicts, 3.3V↔5V level shifting, and running multiple identical devices with a multiplexer — with working examples on Arduino, ESP32, and Pi. The exact converters and expanders used in the guides are below.
Shop the parts used in these tutorials
Pre-Soldered I2C Logic Level Converter 3.3V-5V Bi-Directional for Arduino, Raspberry Pi, ESP32 & Pico
$6.25
TCA9548A Pre-Soldered 1-to-8 I2C 8-Channel Multiplexer Module
$9.99
ADS1115 Pre-Soldered ADC Analog to Digital Converter Module for Arduino & Raspberry Pi
$9.75
BH1750 Pre-Soldered Digital Light Sensor for Arduino & Raspberry Pi
$6.98
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