OpenWrt Forum Archive

Topic: Best I2C GPIO expanders

The content of this topic has been archived on 1 Apr 2018. There are no obvious gaps in this topic, but there may still be some posts missing at the end.

Post #1
jabss
21 Jun 2015, 16:16

Hello,

I'm using the PCF8574/PFC8575 I2C "quasi-bidirectional" GPIO port expander for quite some time, and now I'd like to start using the INTerrupt instead of pooling it.

However, it seems it only works when all ports are configured as input, hence the "Quasi-bidirectional" name. More info on pages 8,9 from http://www.ti.com/lit/an/scpa032/scpa032.pdf.

Having this in mind, I guess I have to take a step further and look for other 8/16 bit GPIO port expanders.

Any suggestion on any device that, like PCF857x, has linux drivers and interrups?

Thanks,
Joaoabs

Post #2
lizby
21 Jun 2015, 16:49

Don't know about Linux drivers and interrupts, but the MCP23017 is a very popular 16-port GPIO expander.

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