This is the code for a simple game, which is based on the interaction with hardware inputs. Basically the game is programmed as a state machine where the states serve as individual levels. The game was implemented for a BeagleBone Black, so all directly hardware related files are specific to this, but as the level of abstraction is quite high it should be fairly easy to port the code to a different hardware.
The basic working principle is a state machine as mentioned. A state is at least defined by a name, next state and a list of conditions for entering the next state. In addition the framework provides the posibility to call arbitrary function when entering and leaving a state. Furthermore the user can pass a function which is executed in parallel in the state in a separate thread.
Conditions are supplied via either the AnalogCondition class which can be used to check for a condition equal, bigger or smaller to a threshold of an analog device or via the DigitalCondition class for binary choices.
The feature list also includes the following gimmicks:
- Central soundserver with play queue
- GUI program to mock the hardware with sliders and buttons to be able
to program without having access to real hardware
In this framework a full 6 level game can be written as simply as:
states =
{0: State('Align Mirror',
AnalogCondition(photo_diode, threshold=0.4, condition='bigger',
hold_true=hold_time, debug=debug), next_states=[1, 1]),
1: State('Change Cavity Length',
AnalogCondition(cavity_poti, condition='equal', equal_epsilon=0.03,
threshold=0.7, hold_true=hold_time, debug=debug),
next_states=[2, 2], parallel_actions=[(cavity_resonant_blinking,
(cavity_blue_led, cavity_green_led,
cavity_poti))]),
2: State('Trap Atom',
AnalogCondition(photo_diode, threshold=0.15, hold_true=hold_time,
condition='smaller', debug=debug), next_states=[3, 3]),
3: State('Tune Frequency Blocking',
AnalogCondition(laser_poti, condition='equal', equal_epsilon=0.1,
threshold=0.2, hold_true=hold_time, debug=debug), next_states=[4, 2],
fail_probability=0.02, random_actions=[(kick_out_atom, atom_eject_servo)],
parallel_actions=[(blink_randomly, (spcm_0_led, spcm_1_led))]),
4: State('Tune Frequency Conjunct Tunneling',
AnalogCondition(laser_poti, condition='equal', equal_epsilon=0.1,
threshold=0.7, hold_true=hold_time, debug=debug),
parallel_actions=[(blink_alternating, (spcm_0_led, spcm_1_led))], next_states=[5, 5]),
5: State('Success', False, next_states=[5, 99],
parallel_actions=[(blink_together, (spcm_0_led, spcm_1_led))]),
}
Have fun building own games!