PTest Software Stack

Testing architecture

At the core of the simulation architecture is the USBSession. This is an integration class that either connects to a Teensy running flight software or to a desktop binary executable, and allows exchanging state fields with the flight software.

Related to the USBSession is the RadioSession, which creates a connection to the email account that PAN uses to talk to the Iridium satellite network. Using this email account, the RadioSession is able to interpret downlinks and send uplinks when requested by the simulation.

At the top level, the SimulationRun architects the Simulation, any USBSession objects, any RadioSession objects, the StateCmdPrompt, and Datastore and Logger objects required by the state sessions, simulation, and radio session.

The State Command Prompt

This is a user-facing CLI that interacts with state session and simulation objects to produce meaningful test behavior. The user has access to a wide selection of commands:

  • rs and ws are used to read state fields and write state fields to a currently selected state session or radio session. wms can be used to write multiple state fields at a time.

    Typical usage is as follows:

    > rs pan.cycle_no
1                                               (Completed in 604 us)
> ws cycle.start true
Succeeded                                       (Completed in 731 us)
> wms pan.state 11 cycle.start true
Succeeded                                       (Completed in 985 us)
> rs pan.cycle_no
3                                               (Completed in 651 us)

    You can find the actual implementation for these commands in USBSession and RadioSession.

  • cycle is shorthand for ws cycle.start (advancing the flight software cycle by 1) and cyclecount is shorthand for rs pan.cycle_no.

  • plot [field] can be used to plot the values of a state field that have been collected so far.

  • listcomp lists the set of available state and radio sessions to connect to.

  • switchcomp can be used to switch between state and radio sessions.

  • checkcomp lists the currently active state or radio session. Typical state/radio session choices include

    • FlightController

    • FlightControllerRadio

    • FlightControllerLeader

    • FlightControllerLeaderRadio

    • FlightControllerFollower

    • FlightControllerFollowerRadio

  • checksim can be used to check how many seconds are left in the current simulation.

  • endsim ends the MATLAB simulation (though this behavior has been a little flaky.)

  • telem is used to extract the most recent telemetry packet off of the spacecraft.

  • parsetelem parses the most recently received packets into a meaningful state.

  • os [field] can be used to override the value of a state field on the current state session so that values sent by the simulation for that state field value are ignored.

  • ro [field] releases the override on a field.

Useful Commands:

  • ws cycle.auto true : DebugTask in flight software will no longer wait for cycle.start to be true before finishing, so Flight Software cycles will automatically proceed.