The “Smart Virtual” Platform

MPF’s Smart Virtual Platform is based on the virtual platform with one key difference: The Smart Virtual platform watches for coil pulse events and adjusts switches in response to simulate how those switches would have changed if that coil fired on real hardware.

To understand why the smart virtual platform exists, consider this simple machine config for a trough, a plunger lane, and keyboard key mappings to simulate their switches:

switches:
    s_trough1:
        number: s31
    s_trough2:
        number: s32
    s_trough3:
        number: s33
    s_trough4:
        number: s34
    s_plunger_lane:
        number: s27

coils:
    c_trough_eject:
        number: c01
        pulse_ms: 25
    c_plunger_eject:
        number: c03
        pulse_ms: 25

ball_devices:
    bd_trough:
        tags: trough, home, drain
        ball_switches: s_trough1, s_trough2, s_trough3, s_trough4
        eject_coil: c_trough_eject
        eject_targets: bd_plunger
    bd_plunger:
        ball_switches: s_plunger_lane
        eject_coil: c_plunger_eject
        tags: ball_add_live

keyboard:
    1:
        switch: s_trough1
        toggle: true
    2:
        switch: s_trough2
        toggle: true
    3:
        switch: s_trough3
        toggle: true
    4:
        switch: s_trough4
        toggle: true
    p:
        switch: s_plunger_lane
        toggle: true

MPF’s regular virtual platform interface is “dumb” in the sense that all switch actions need to be controlled externally (either via keyboard keys, the OSC interface, etc.)

So if you have the above configuration and then MPF wants to eject a ball from the trough, it will fire the trough coil but the switches won’t actually change. (In fact this will cause MPF to think that the eject failed, because it will fire the eject coil and not see the ball leave.)

If you wanted to “play” an MPF game with the example config above, you’d have to manually manually simulate the ball leaving the trough by hitting the “1” key to deactivate a trough switch, and then hitting the “P” key to activate the plunger lane switch. (And you’d have to do this fast enough for the eject failure detection not to kick in.)

A better solution? The “smart” virtual interface.

In order to address these challenges, MPF includes a smart virtual platform interface. The smart virtual interface works by watching for coil pulse commands. If it sees a coil pulse from a coil that’s configured in a mechanism that would ordinarily cause a switch to change state, then it will automatically change that switches state.

For example, if you have the trough config from above and the trough’s eject coil fires, the smart virtual platform will look to see if there are any balls in that device, and, if so, simulate the ball leaving (which could be by deactivating one of the device’s ball switches).

The smart virtual platform also knows (thanks to the eject_targets: ball device setting) where the ball is ejected to, so when a ball is ejected from a device, the smart virtual platform will also simulate the ball going into the target ball device.

Going back to the example machine config above, if the smart virtual platform interface is being used, when a game is started, you’ll see the s_trough1 switch automatically deactivate in response to the trough coil pulsing, and then 100ms later you’ll see the s_plunger switch activate to simulate a ball going into the plunger lane. So simply starting a game with the smart virtual platform puts the ball in the plunger lane without you having to mess with the “1” and “P” keys.

Using the smart virtual platform

There are three ways you can use the smart virtual platform:

1. No platform setting

If you do not have a platform: setting in your machine config’s hardware: section (or if you don’t have a hardware: section, then MPF will use the smart virtual platform anyone you run it.

2. Manually setting the platform

You can also manually specify the smart virtual interface in the machine config, like this:

hardware:
    platform: smart_virtual

3. Via the command line

You can also specify the smart virtual platform interface via the -X (uppercase X) from the command line, like this:

mpf -X

Or

mpf both -X

etc.

What does the smart virtual platform do?

The smart virtual platform currently simulates the following pinball mechanisms:

Ball Devices

If a ball device’s eject coil is pulses, it will simulate a ball leaving that device (as long as that device has at least one ball). It is smart enough to know how many balls are in a device, and works with special scenarios (such as timed entrance switches that are only active when the device is full and eject confirmation switches).

It will also simulate a ball entering the target device when a ball is ejected, and again it knows how to work with various ball switch and entrance switch combinations.

Drop Targets

The smart virtual platform will reset drop target switches if their associated reset coil is pulsed.