https://github.com/rhthomas/kw41z-dev
COMP3215 Lab 1 – Implementing FreeRTOS using multiple development environments.
https://github.com/rhthomas/kw41z-dev
arm-cortex-m0 freertos gnu-toolchain keil nxp rtos
Last synced: 2 months ago
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COMP3215 Lab 1 – Implementing FreeRTOS using multiple development environments.
- Host: GitHub
- URL: https://github.com/rhthomas/kw41z-dev
- Owner: rhthomas
- Created: 2017-10-23T18:43:58.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2017-11-13T00:34:04.000Z (over 7 years ago)
- Last Synced: 2025-01-25T16:32:00.221Z (4 months ago)
- Topics: arm-cortex-m0, freertos, gnu-toolchain, keil, nxp, rtos
- Language: C
- Size: 2.41 MB
- Stars: 0
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# KW41Z-Dev
The idea of this lab exercise is to get experience and realise the pros and cons of different development environments. To demonstrate this, a simple RTOS program will be written, flashed and debugged for the FRDM-KW41Z on three different development environments:
1. ARM Keil
2. NXP MCUXpresso
3. GNU FOSS Toolchain and Makefiles
The directory structure for this repository is as follows:
```
KW41Z-Dev/
├── GNU/
│ ├── README.md
│ ├── RTOS_Blink/
│ └── img/
├── Keil/
│ ├── README.md
│ ├── RTOS\ Blink/
│ └── img/
├── MCUXpresso/
│ ├── README.md
│ ├── RTOS_Blink/
│ └── img/
└── README.md
```
---
## Simple RTOS Program
The RTOS program that will be written for the processor will simply toggle two different LEDs with different periods. A red on at 500ms, and a green one at 330ms.
Below is segments of the FreeRTOS functionality **ONLY**, i.e. no development platform specific functions or includes.
### Main Function
The job of the main function is to create the two LED tasks and begin the OS scheduler.
```c
int main(void)
{
// Create red LED task.
xTaskCreate(
LEDTask1, // Task function.
"LEDTask1", // Task name (for simulations).
configMINIMAL_STACK_SIZE, // Size of task stack.
(void *)NULL, // Parameter passed to task at startup.
(unsigned portBASE_TYPE)tskIDLE_PRIORITY+1, // Priority.
(xTaskHandle *)NULL // Pointer to reference of the task.
);
// Create green LED task.
xTaskCreate(
LEDTask2, // Task function.
"LEDTask2", // Task name (for simulations).
configMINIMAL_STACK_SIZE, // Size of task stack.
(void *)NULL, // Parameter passed to task at startup.
(unsigned portBASE_TYPE)tskIDLE_PRIORITY+1, // Priority.
(xTaskHandle *)NULL // Pointer to reference of the task.
);
// Start OS scheduler.
vTaskStartScheduler(); // No return!
return 0;
}
```
### LED Tasks
The LED tasks are very basic. They consist of a while loop that forever turns on an LED, waits a period of time, then turns off the LED before again waiting. This is not at all efficient code however it is meant to only be a simple example.
```c
void LEDTaskN(void *pvPs)
{
while (42) {
// Turn LED on.
vTaskDelay( tDelay_ms(500) );
// Turn LED off.
vTaskDelay( tDelay_ms(500) );
}
}
```
### Converting RTOS *Ticks* to Seconds
For the `vTaskDelay` function, we cannot simply pass a millisecond wait time, we need to convert this to RTOS processor *ticks* which is done using a small converter function.
```c
portTickType tDelay_ms(const float ms)
{
return (portTickType)(ms / portTICK_PERIOD_MS);
}
```
---
## Comparison Between Development Platforms
### ARM Keil
#### Pros
+ Easy to use debugging interface.
+ Able to batch build for multiple targets.
+ Well designed and easy to use package manager.
#### Cons
- 32kB code limit.
- Very expensive full version of the software.
- Pulls in files from a variety of locations. Not sure what you're including.
### MCUXpresso
#### Pros
+ Cross-platform IDE.
+ Free.
+ IDEs allow more time writing code rather than wasting time figuring out the toolchains.
+ Easy debugging interface.
+ Familiarity to those who have used Eclipse tools in the past.
#### Cons
- Based on Eclipse so is a fairly heavy editor for embedded platforms.
- Most of Eclipse isn't even used!
### GNU Toolchains
#### Pros
+ Free.
+ You know exactly what files are being compiled into your project.
+ More control over code size.
+ More control over security.
+ Not pulling in random libraries you didn't write.
+ Lightweight IDEs.
+ Just need a text editor and a terminal.
+ Use whatever text editor you like.
+ Atom
+ Vi/Vim
+ Nano
+ Notepad++
#### Cons
- Makefiles can be very complicated/convoluted.
- Spend more time debugging makefiles rather than actual code.
- More complicated methods of making linker scripts.
- More time spent setting up the toolchains rather than actually writing functional code for the target.
- GDB in the command line has a steep learning curve.