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TcMenu / IoAbstraction

Rotary encoders, fully debounced switches, EEPROM support on Arduino and mbed - direct and over I2C
Apache License 2.0
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Support for PCF8575C 16-bit I2C I/O expander #157

Closed vzahradnik closed 2 years ago

vzahradnik commented 2 years ago

Hi,

In my Arduino project I use PCF8575C expander and I'd like to integrate it with your library without any hacks. Currently I use the following library: https://github.com/4-20ma/I2cDiscreteIoExpander

I could implement a wrapper around the library with your IoAbstractionRef abstraction, however, the cleanest approach seems to me to add direct support into this library, similarly to PCF8574.

Any guidance is highly appreciated. For starters, I'd like to know which repositories need to be modified. This one for sure, but I'd like to have full support, including TcMenu builder.

Thanks!

davetcc commented 2 years ago

It looks like this should be a very trivial task. The PCF8575 basically acts like two PCF8574. The protocol is exactly the same. I will have a go at adjusting the current PCF8574 class to support both. It should be nothing more that changing to class to send and receive either one or two bytes depending on device.

davetcc commented 2 years ago

For tcMenu I’m already trying to sort out the webserver remote management support and it should be really quick to add this in at the same release.

vzahradnik commented 2 years ago

It looks like this should be a very trivial task. The PCF8575 basically acts like two PCF8574. The protocol is exactly the same. I will have a go at adjusting the current PCF8574 class to support both. It should be nothing more that changing to class to send and receive either one or two bytes depending on device.

Is there anything I could help with? I need the support now so I'm prepared to code it by myself and contribute back. If you point me to what you'd like to change and how, I can start working on that.

davetcc commented 2 years ago

It's trivial enough that I'll have a go at adding the support and if you can test it with the device that would be great.

vzahradnik commented 2 years ago

Sure, I will happily do that :)

davetcc commented 2 years ago

You can look at the two files I've committed (that are shown in the issue), I don't have the device so can't test it, but I did test it with a PCF8574 and it should work in theory.

To use it in TcMenu just set the expander type in designer to custom for now and declare the expander with the same name in your sketch file. See the online help button on the expander editor for more on how to do that.

In the next tcMenu release I'll add it properly so at that point you wouldn't need the custom code.

inline IoAbstractionRef ioFrom8575(uint8_t addr, pinid_t interruptPin = 0xff)

vzahradnik commented 2 years ago

Thanks, I will test that tomorrow.

vzahradnik commented 2 years ago

@davetcc your code works perfectly. It's ready to be merged.