MIGRATION

		Migration from wiringPi to PIGPIO.
		==================================

WiringPi is unmaintained and replaced by pigpio. This will need large parts
of thermferm to be rewritten. It is also a good moment to replace the current
server protocol with json data and start sending data chaanges over
websockets.

Some parts of the code can make use of direct kernel support, since kernel 4
there are lots of new modules. Fact is that thermferm is started in 2014,
that is 10 years ago.

The current devices model is not very practical. We need to separate the parts
that don't need gpio out of it. All one-wire devices need their own driver
thread.


	Current threads.
	----------------

These are the current running threads.
1. my_devices_loop.
2. my_server_loop.
3. my_panel_loop.
4. my_simulator_loop (if enabled).


	Steps to do.
	------------

Write a new thread for the one-wire devices. Make it a dynamic table. The
old device table is still needed to tie devices to fermenters.
Try to read all temperature sensors at once. The kernel supports this now.
The devices thread needs to use the collected temperatures.
Read all ds2413 devices from sys/bus/w1. If output bits are set different
then send output values.
Create tables for ds28b20 and ds2413. Simulated and real sensors should
share these tables.


Add pigpio library and make it testable by the configure script.


	Flow one-wire.
	--------------

States:
  1. Init state.
  2. Check for exit.
     Scan for devices. Add to one-wire list.
  3. Check for exit.
     Read all DS2413 devices programmed as input.
  4. Check for exit.
     Read one temperture sensor from list and update device.
  5. Check for exit.
     Check for missing devices not in one wire table.
     Goto 2.
  6. Exit state.