Switchboard Automation Framework

IoT automation is conceptually simple: when (a) happens do (b) and wait 3 seconds before also do (c). But what if (a) comes from a Raspberry Pi, (b) is a desktop computer and (c) an ESP8266 WiFi module? Who should be in charge of controlling this functionality? What should we do if WiFi becomes temporarily unavailable?

These are a few of the many hard questions I had to ask myself when deciding how to connect my devices together in a meaningful way. To this end I've been slowly piecing together a Python framework called Switchboard which takes care of device connectivity, availability, is easy to write logic for and is dynamically configurable through a command line interface.

• the Switchboard framework runs on a base station (x86 computer or Raspberry Pi)
• polls Switchboard clients via a simple HTTP REST Api
• input and output devices can be directly read from and written to by a Switchboard module, which is effectively a function with a decorator
• writing a Switchboard module is DEAD EASY: 1) specify a decorator with the desired inputs and outputs, 2) specify arguments to match the inputs and the outputs and 3) write your logic, knowing that all the connectivity is taken care of
• Python and C++ ESP8266 Switchboard client libraries (maybe also Arduino with an Ethershield if I get round to it)
• resilient to network outage
• easy to use command line prompt for dynamic Switchboard configuration: adding, updating or removing a piece of functionality is performed without affecting unrelated devices and modules

1. Download repository
2. Run python setup.py install
3. To execute, run switchboard -c <settings file>. -c can be used to specify a settings file and is optional.

When Switchboard is running it presents a command-line interface to configure and operate the framework. Where possible these commands feature tab completion.

• addclient [client] [alias] adds a new client and assigns an alias to it. Example addclient 192.168.1.2:3000 pc
• addclient [client] [alias] [poll_period] adds a new client and polls it at roughly max(poll_period, Switchboard_poll_period). Example addclient 192.168.1.2:3000 pc 5.0: poll roughly every five seconds if the Switchboard poll period is < 5.0s.
• updateclient [client alias] reloads an existing client
• updateclient [client alias] [poll_period] reloads an existing client and updates its poll period. If poll_period == 'None' the client is polled at every Switchboard cycle.
• addmodule [module] adds or updates a Switchboard module and enables it. Example addmodule test_module.module (from the simple_counters example code)
• remove [client|module] removes client or module
• enable [module] enables a Switchboard module
• disable [module] disables a Switchboard module. Currently this does not disconnect any output signals driven by the module
• launchapp [app] launches an app an prompts for its arguments through the Switchboard command-line interface. In order to support this functionality the app needs to provide a --getconf argument. If the application needs an IOData connection and/or acts as a Switchboard client these connections are automatically established.
• killapp [app] terminates an app.
• list [clients|devices|values|apps|modules] lists all the currently known clients, devices, values, apps or modules
• get [device|config] prints the value of an input device or of a simple config option such as polling period
• set [device|config] [value] sets the device or config option to given value
• start starts the Switchboard module engine
• stop stops the Switchboard module engine
• exit quit Switchboard