[Extend Dallas 1-Wire] Add support for read PIO-A of DS2406

[rmcbc]

Extend Dallas 1-Wire

Extend the devices supported with DALLAS 1-WIRE.
The DS2406 can be read, the system adds it as a digital device and only read PIO-A state.

Electronics

1. Connect a 3.3Kohm resistor from pin 3.3V to IO2 (pad after 3.3V hole) on a Sonoff Basic R2.
2. Take 3 wires: GND, 3.3V and IO2 (I think is GPIO14)
3. Connect DS2406 pin 1 to GND, pin 2 to IO2 and pin 3 is the input port

Just a Note: if it's to receive a signal from a relay I put a 10K resistor to 3.3v as a pull up or to GND as a pull down depending if relay NC is GND or 3.3v and NO is a open signal)

Devices

To have access to DALLAS devices I use in platformio:
default_envs = itead-sonoff-basic-r2-dallas

You can mix DS18x20 devices with this new DS2406.

Because only have 5 units of DS2406, I test all in the same Sonoff, it detects all and work without any problem.

[mcspr]

I have noticed that the other sections does check for the 'expected' return value. Should it do the same here, and the one reset() below?

https://github.com/PaulStoffregen/OneWire/blob/master/OneWire.cpp#L164

// Returns 1 if a device asserted a presence pulse, 0 otherwise.

Based on the commit history, hot-plugging is the reason for that branch:
90c5155

[rmcbc]

@mcspr you were right, sorry for that.
Fixed, thanks.