I2C scanner

An I2C scanner sketch is introduced. This allows to determine I2C addresses or to check non-functioning circuits with I2C component.

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Port expander MCP23017

The 16-bit I/O port expander MCP23017 is introduced including a library. The functions are explained by sketches and circuits.

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Counter ICs

The counter ICs 4040, 4017 and 4033 will be presented. In addition to the counter function, I explain how to use the counters for port expansion.

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ESP-01 port expansion

Port expansion for the ESP-01 using the MCP23017, PCF8574 and the 74HC595 shift register are explained in this post. With circuits and sample sketches.

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ESP8266 ESP-01 module

Controlling ESP-01 modules with the Arduino IDE is explained step by step. I provide example sketches with circuits. Also: AT commands.

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