Help configuring a MCP23017 expander with an ESP32 for interrupt handling

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1

Hi, I have a board with an MCP23017 GPIO expander and an ESP32. The expander has its INT B pin (pin 19) connected directly to ESP32 GPIO 0 (pin 25). There is no pullup or pulldown resistor.

I'm trying to get the expander to trigger an interrupt handler in the ESP32. I can configure the expander, and the ESP32, but I'm unsure how to configure each. Should the expander be configured as open drain and the ESP32 have the internal pullup activated on the ESP32, with GPIO 0 configured as input?

Thanks very much.

2

Please help finding a data sheet of the MCP23007. Many links refer to MCP2017 or MCP2008 but these may have different interrupt pin circuits. Have you tried the Adafruit MCP20xx library?

3

DrDiettrich:
Please help finding a data sheet of the MCP23007. Many links refer to MCP2017 or MCP2008 but these may have different interrupt pin circuits. Have you tried the Adafruit MCP20xx library?

My mistake, I meant the MCP23017:

Yes I have tried the Adafruit library, that will let me configure the chip but I'm still not sure how it should be configured.

4

Have you tried the examples coming with the library and in the Adafruit sites?

The interrupts can be configured as best suited for your project. Open drain allows to connect multiple interrupt lines to one input pin. Find out yourself which combinations you like best...