51 lines
1.3 KiB
Markdown
51 lines
1.3 KiB
Markdown
## Blinky
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The classic, the helloWorld of embedded programming. This program turns the LED on and off periodically.
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### Initial steps:
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- Create new project with project generator.
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- Open the project folder in VSCode.
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- Build the project by pressing the `build` button at the bottom and select the option with `arm-none-eabi`.
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- Make sure the build exits with code 0.
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<img src="../assets/buildButton.png" width="300">
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### Basic Code:
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``` C
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int main()
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{
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stdio_init_all();
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const uint OnBoardLED = PICO_DEFAULT_LED_PIN;
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gpio_init(OnBoardLED);
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gpio_set_dir(OnBoardLED, GPIO_OUT);
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while (true){
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gpio_put(OnBoardLED, true);
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sleep_ms(500);
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gpio_put(OnBoardLED, false);
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sleep_ms(500);
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}
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}
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```
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#### Explanation:
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`stdio_init_all()`: initialize stuff
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`OnBoardLED = PICO_DEFAULT_LED_PIN`: Get the GPIO number of onboard LED. Remember this is GPIO Number, NOT PIN NUMBER.
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`gpio_init(OnBoardLED)`: Initialize that GPIO pin.
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`gpio_set_dir(OnBoardLED, GPIO_OUT)`: Set GPIO direction (`GPIO_OUT` for writing and `GPIO_IN` for reading).
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`while (true){}`: Super loop of the program
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`gpio_put(OnBoardLED, true)`: Set `OnBoardLED` pin to `on` (`true` to turn on/set to high/voltage to VDD, `false` to turn off/set to low/voltage to GND)
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Pico login HIGH voltage is 3.3v and LOW voltage is 0v.
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`sleep_ms(500)`: sleep for 500ms.
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---
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