Next steps shows how the master (Arduino) reads from the slave I2C device. Wire.requestFrom(address, 1) command expects to receive 1 byte of data from the TC74 sensor. Wire.available() waits for data ...

Step-by-step guide on designing and programming a custom I2C slave sensor device using Arduino. More for You. Trump overpowers Musk's attacks on mega tax bill with blizzard of orders.

In principle, such backpacks are built aorund PCF8574 (from NXP) which is a general purpose bidirectional 8 bit I/O port expander that uses the I2C protocol. The PCF8574 is a silicon CMOS circuit ...

The Rev3 has a single serial connection, shared by the USB port and the RX/TX pins. There's also only one I2C bus on the Rev3. In contrast, the R4 WiFi includes two serial ports and two I2C buses.

I wrote some I2C sniffer code for a silabs C8051F340 MCU one time. On that MCU, it has specialized I2C hardware, so you only have to peek/poke certain registers to make the I2C bus do what you want.