LED Blinker: Initial Component Integration

In this section, users will create a deployment and perform the initial integration of the LED component into that deployment. This deployment will automatically include the basic command and data handling setup needed to interact with the component. Wiring the Led component to the GPIO driver component will be covered in a later section after the component implementation has finished.

Users must have created the initial Led component implementation in order to run through this section. Users may continue to define commands, events, telemetry, and ports after this initial integration.

Creating the LedBlinker Deployment

In order to produce an executable to run the software, users need to create a deployment. A deployment is one software executable that contains the main entry point, and an F´ system topology.

Create a new deployment in the led-blinker directory with:

#In led-blinker
fprime-util new --deployment

This will ask for some input, respond with the following answers:

[INFO] Cookiecutter: using builtin template for new deployment
Deployment name [MyDeployment]: LedBlinker
Select communication driver type:
1 - TcpClient
2 - TcpServer
3 - UART
Choose from 1, 2, 3 [1]: 2
[INFO] Found CMake file at 'led-blinker/project.cmake'
Add component LedBlinker to led-blinker/project.cmake at end of file? (yes/no) [yes]: 

Use the default response for any other questions asked.

In order to check that the deployment was created successfully, the user can build the deployment. This will build the code for the current host system, not the remote embedded hardware allowing local testing during development.

# In led-blinker
cd LedBlinker
fprime-util build

This will reuse the build cache created during the project creation. CMake warnings may appear to indicate that the build cache is refreshing. The build should start shortly thereafter.

Adding Led Component To The Deployment

The component can now be added to the deployment’s topology effectively adding this component to the running system. This is done by modifying instances.fpp and topology.fpp in the Top directory.

Add the following to led-blinker/LedBlinker/Top/instances.fpp. Typically, this is added to the “Active component instances” section of that document.

  instance led: Components.Led base id 0x0E00 \
    queue size Default.QUEUE_SIZE \
    stack size Default.STACK_SIZE \
    priority 95

This defines an instance of the Led component called led. Since the component is active it needs a queue size, stack size, and priority for the thread of the component and the queue that thread serves. We have chosen the topology specified defaults and a priority of 95.

Next, the topology needs to use the above definition. This is done by adding the led instance to the list of instances defined in led-blinker/LedBlinker/Top/topology.fpp:

    # ----------------------------------------------------------------------
    # Instances used in the topology
    # ----------------------------------------------------------------------

    instance led

No port connections need to be added because thus far the component only defines standard ports and those are connected automatically.

Testing the Topology

The topology may now be run. This can be done with the fprime-gds command. Since we are currently building for the host platform, that command will run the ground data system (GDS) and the deployment executable automatically in-tandem.

Make sure to build the deployment first with fprime-util build

fprime-gds --ip-client

This will likely open up your browser and show the running flight software. If it does not open a browser, navigate to http://localhost:5000.

Test the component integration with the following steps:

1. Verify connection: confirm that there is a green circle and not a red X in the upper right corner.
2. Send a Command: select the ‘Commanding’ tab, search for led.BLINKING_ON_OFF and send it with the argument set to ON.
3. Verify Event: select the ‘Events’ tab and verify that the SetBlinkingState event reports the blinking state was set to ON.

CTRL-C to stop the F´ GDS program.

Conclusion

Congratulations! You have now integrated your component and tested that integration.

Return to the led-blinker/LedBlinker and run the following commands to test whenever you desire.

#In led-blinker/LedBlinker
fprime-util build
fprime-gds  --ip-client

# CTRL-C to exit

This tutorial will return to the component implementation before finishing the integration of the component and testing on hardware.

Next Step: Continuing Component Implementation.