FLAGS HAL device added to IODevice.h, which allows use of SET/RESET/<Z>/<T> to set and reset a VPIN state, and to allow <S>/IF/IFNOT/AT/WAITFOR/etc. to monitor the VPIN state.
Also, correct handling of VPINs above 32767 in DIAG calls within IODevice.cpp and IODevice.h.
UserAddin allows a function to be 'plugged in' to the IODevice (HAL) framework and executed cyclically, using just one line of code in the myHal.cpp. This will facilitate functions for displaying CS state on OLEDs and LCDs, among other things.
Change I2C addresses from uint8_t to I2CAddress, in preparation for MUX support. Currently, by default, I2CAddress is typedef'd to uint8_t.
MUX support implemented for AVR and Wire versions.
Filter drivers provide extra functionality above a hardware driver. For example, a hardware driver for a PWM module may just set the PWM ratio, but a separate filter driver could animate motors or servos over time, calling the PWM driver to output the pulses. This would allow the animations to be easily implemented on a different type of PWM module.
To support nested drivers efficiently (i.e. to allow the higher driver to call another driver directly, without searching for a VPIN every time), the visibility of the IODevice::findDevice() function has been changed from private to protected.
If an Arduino pin was used as an input (e.g. by EXRAIL) without previously configuring it, the default pullup wouldn't be set up. Now, on first call to the _read() method the pullup will be enabled.
Previously, pullups were enabled on GPIO Expander digital pins by default, even if the pin was only ever used as an output. This could lead to a spurious HIGH state being seen by external equipment before the output is initialised to LOW. To avoid this, the pin pullup is now not enabled until a configure or read operation is issued for the pin.
Remove virtual method hasCallback().
Optimise findDevice() method (used by read, write etc.).
Simplify Sensor handling with regard to IO Devices that support callbacks.
Performance enhancements in IODevice::loop() function.
Improved error handling, device is placed off line if not responding.
Improved error reporting, device shown as offline if not operational (faulty or not present).
When writing to analogue outputs pins, the digital _read() function now returns the 'busy' status of the analogue pin. Consequently, the _isBusy() function becomes superfluous and has been removed. The static IODevice::isBusy() function now calls the object's _read() function instead.
Also, limit in DFPlayer of 3 pins has been removed.
When writing to a PWM device (servo or LED for example), it is possible to request the target position in the call, or to ask for a SET or RESET position. In the latter case, the positions corresponding to SET and RESET must be known, i.e. preconfigured. Defaults were assigned for this, but because the correct values will depend on the hardware device being driven, the defaults have been removed.
In addition, the <T> command, when defining a servo turnout, now configures the PWM positions (not required by <T> commands, but desirable for consistency with other commands).
IODevice::writeAnalogue() has an additional optional parameter "duration", specifying the time taken for the animation in units of 100ms (max 3276 seconds, or about 54 minutes).
