Brewery

Gadgets was orignially created to run my automatic brewery. The brewery looks something like this:

The gadgets system is created like this:

from gadgets import GadgetsFactory
from gadgets.pins.beaglebone import pins

args = {
    'locations': {
        'brewery': {
            'fan': {
                'type':'switch',
                'pin': pins['gpio'][8][17],
            },
        },
        'hlt': {
            'valve': {
                'type': 'valve',
                'pin': pins['gpio'][8][11],
                'trigger': {
                    'type': 'float',
                    'pin': pins['gpio'][8][12],
                    'volume': 26.5,
                },
            },
            'heater': {
                'type': 'electric heater',
                'pin': pins['gpio'][8][25],
            },
            'thermometer': {
                'type': 'thermometer',
                'uid': '28-000002b01241'
            }
        },
        'tun': {
            'valve': {
                'type': 'valve',
                'pin': pins['gpio'][8][14],
                'trigger': {
                    'type': 'gravity',
                    'source': 'hlt',
                    'tank_radius': 7.5,
                    'valve_radius': 0.1875,
                    'valve_coefficient': 0.43244,
                },
            },
            'thermometer': {
                'type': 'thermometer',
                'uid': '28-0000025ed750'
            }
        },
        'boiler': {
            'valve': {
                'type': 'valve',
                'pin': pins['gpio'][8][15],
                'trigger': {
                    'type': 'timer',
                    'source': 'tun',
                    'drain_time': 4 * 60,
                },
            },
            'heater': {
                'type': 'electric heater',
                'pin': pins['gpio'][8][24],
            },
            'cooler': {
                'type': 'cooler',
                'pin': pins['gpio'][8][22],
            },
            'thermometer': {
                'type': 'thermometer',
                'uid': '28-0000025f0aba',
            }
        },
        'carboy': {
            'valve': {
                'type': 'valve',
                'pin': pins['gpio'][8][16],
                'trigger': {
                    'type': 'user',
                    'source': 'boiler',
                }
            }

        }
    }
}

factory = GadgetsFactory(ensure_off=True)
gadgets = factory(args)
gadgets.

Brewing a batch of beer is done using a RCL method. The RCL method is handled by a MethodRunner. The MethodRunner broadcasts the commands in the method. Here is an example method for brewing beer:

heat hlt 176.2 F
wait for heat hlt

The ‘heat hlt 176.2 F’ command will get intercepted by the hlt heater. The heater will turn on the electric heating coils and heat the hot liquor tank (hlt) to 176.2 F. Once that temperature is reached it sends out a message like this:

completed heat hlt

The second RCL command (wait for heat htl) causes the MethodRunner to pause until the ‘completed heat hlt’ command is broadcast. The method then continues:

fill tun 5.0 gallons
heat tun 151 F
wait for fill tun
wait for user grains added

Here is another example of a special RCL command that is used by the MethodRunner. ‘Wait for user’ is for steps that require human intervention. The built in curses user interface listens for a ‘wait for user’ command and then puts a message on the screen telling the user to press a certain key when the task is complete. So in this case the user would hit the key after the grains have been added to the mash. The user interface will then send this message:

completed grains added

And once again, the RCL method will continue:

fill hlt
heat hlt 185 F
wait for 60 minutes

The ‘wait for 60 minutes’ is another command that is used by the MethodRunner. The method runner will start a timer that will restart the method after 60 minutes:

fill tun 6.0 gallons
wait for 10 minutes
wait for user ready to recirculate
fill boiler
wait for user recirculated
fill boiler 1
heat boiler 190 F
wait for fill boiler
fill tun 4.0 gallons
wait for fill tun
stop heating hlt
wait for 2 minutes
wait for user ready to recirculate
fill boiler
wait for user recirculated
fill boiler
heat boiler 204 F
wait for 90 minutes
stop heating boiler
wait for 10 minutes
cool boiler 80 F
wait for 10 minutes
fill carboy
wait for user carboy filled
stop filling carboy