Kubos SDK Example Applications¶
We have provided a variety of example applications to help you get started with your Kubos project. These examples are located in the ‘Examples’ folder of the Kubos repo, as well as within the /home/vagrant/.kubos/kubos/examples folder of the Kubos SDK box.
Using an Example Application¶
Each of the example applications contains the files necessary to run as an independent Kubos project.
This means you can simply copy the desired example to a new folder and immediately build it with the kubos build command.
Note: The default target for all of these applications is stm32f407-disco-gcc.
You will need to manually change the target if this is not your desired endpoint device.
Exception: The kubos-linux-example application was designed specifically to run on KubOS Linux.
Since the stm32f407-disco-gcc target does not support KubOS Linux, this application will fail to build sucessfully until the target is changed to a board which is KubOS Linux-compatible.
“Compatible Targets” indicates which target boards the application should work on without modification.
KubOS RT Example¶
Compatible Targets: All KubOS RT compatible targets
| High-level Component | Specific Area |
|---|---|
| Kubos HAL [3] | GPIO |
| CSP [4] | Sockets, ping |
| FreeRTOS [5] | Threads, queues |
This is the default application included when the kubos init command is executed.
It is intended to provide an overview of several components as they might run in a KubOS RT application.
Four threads are created:
- A CSP server
- A CSP client
- A button poll
- An interval print
The interval thread prints out “echo, x={n}” to the default UART port, where {n} is a basic counter.
The button poll thread continually polls the board’s button to see if it has been pressed. If it has, a notification is added to a dedicated queue.
The CSP client thread checks for messages on the button queue. If found, it connects to the CSP server’s port and sends a message “Hello World”.
The CSP server thread checks for connections on the CSP port and then blinks the green LED if any messages are received.
KubOS Linux Example¶
Compatible Targets: All KubOS Linux compatible targets
| High-level Component | Specific Area |
|---|---|
| Kubos CSP [4] | sockets, ping, threads |
This is the default application included when the kubos init --linux command is executed.
It is intended as a basic example of how an application could be written to run on a KubOS Linux system.
The application contains a CSP interaction between client and server tasks.
Every 200ms, the CSP client thread pings the CSP server’s address to see if it is available, and then connects and sends a CSP packet containing the message “Hello World”.
The CSP server thread checks for connections on the CSP port and then prints any received messages to STDOUT.
Kubos Sensor Example¶
Compatible Targets: STM32F407 Discovery
| High-level Component | Specific Area |
|---|---|
| config.json [1] | Sensors |
| Kubos Core [2] | altimeter, temperature |
| FreeRTOS [5] | Threads |
This application provides a streamlined approach to using the BME280 humidity/pressure sensor and the HTU21D temperature/humidity sensor.
Kubos CSP Example¶
Compatible Targets: All KubOS RT compatible targets
| High-level Component | Specific Area |
|---|---|
| Kubos HAL [3] | GPIO |
| CSP [4] | Sockets, ping, threads, queues |
This application shows an example CSP interaction between client and server tasks.
Three threads are created:
- A CSP server
- A CSP client
- A button poll
The button poll thread continually polls the board’s button to see if it has been pressed. If it has, a notification is added to a dedicated queue.
The CSP client thread checks for messages on the button queue. If found, it connects to the CSP server’s port and sends a message “Hello World”.
The CSP server thread checks for connections on the CSP port and then blinks the green LED if any messages are received.
Kubos I2C Example¶
Compatible Targets: MSP430F5529, STM32F407 Discovery
| High-level Component | Specific Area |
|---|---|
| config.json [1] | Sensors |
| Kubos Core [2] | HTU21D sensor, BNO055 sensor |
| Kubos HAL [3] | I2C, GPIO |
| FreeRTOS [5] | Threads |
This application gives several examples of how to interact with I2C devices in a Kubos project:
If no sensor has been defined in the project’s config.json file, then this application will initialize a generic I2C connection over I2C bus 1 to a slave device with an address of ‘0x40’.
It will then write a single byte command of ‘0xE3’ to the slave and attempt to read back a three byte response.
After this attempt, the application will end.
If the HTU21D sensor has been defined in the project’s config.json file, the appropriate initialization calls will be made and then the application will enter a loop.
In each iteration of the loop, the application will fetch and print the current temperature and humidity data from the sensor to the default UART port.
If the BNO055 sensor has been defined in the project’s config.json file, the sensor will be initialized in NDOF (Nine Degrees Of Freedom) mode and then the application will enter a loop.
In each iteration of the loop, the application will fetch and print the current position data from the sensor to the default UART port.
Kubos SPI Example¶
Compatible Targets: STM32F407 Discovery
| High-level Component | Specific Area |
|---|---|
| config.json [1] | Sensors |
| Kubos Core [2] | BME280 sensor |
| Kubos HAL [3] | SPI, GPIO |
| FreeRTOS [5] | Threads |
This application gives two examples of how to interact with SPI devices in a Kubos project:
If no sensor has been defined in the project’s config.json file, then this application will initialize a generic SPI connection over SPI bus 1.
The application will then enter a loop and attempt to send and receive a dummy byte.
Note: This case is not a complete example, because it omits the manual manipulation of a chip select pin that is required for SPI communication.
If the BME280 sensor has been defined in the project’s config.json file, the appropriate initialization calls will be made and then the application will enter a loop.
In each iteration of the loop, the application will fetch and print the current temperature and humidity data from the sensor to the default UART port.
Kubos SD Example¶
Compatible Targets: MSP430F5529, STM32F407 Discovery
| High-level Component | Specific Area |
|---|---|
| config.json [1] | FS |
| Kubos Core [2] | FatFS |
| FreeRTOS [5] | Threads |
This application runs a series of commands against an SD card connected to SPI bus 1 using the FatFS library.
The application covers how to:
- Mount/unmount a SD card
- Open a file for writing (file will be created if it doesn’t exist)
- Open a file for reading
- Close a file
- Write a string to a file
- Read a specified length from a file
- Sync the file system
- Get the stats (size, timestamp, attributes) of a file
References¶
| [1] | (1, 2, 3, 4, 5) config.json - Kubos project file for custom configuration options |
| [2] | (1, 2, 3, 4) Kubos Core - Kubos built-in peripheral device support |
| [3] | (1, 2, 3, 4, 5) Kubos HAL - Kubos hardware abstraction for interfacing with peripheral devices |
| [4] | (1, 2, 3) CSP - (Cubesat Space Protocol) Lightweight communication protocol |
| [5] | (1, 2, 3, 4, 5, 6) FreeRTOS - The RTOS which KubOS RT is built on |