Moving from Arduino to STM32:
Your First "Bare Metal" Project

We all started with Arduino. It’s easy, it’s fun, and `digitalWrite(13, HIGH)` is etched into our brains. But eventually, you hit a wall.

Maybe you need to sample a sensor at 1 MHz, or you need true hardware debugging because your code keeps crashing. That is when you graduate to STM32.

Today, I’m going to show you how to set up the professional toolchain (STM32CubeIDE) and write your first code without the Arduino training wheels.

Why Leave Arduino?

Don't get me wrong, I love Arduino for quick hacks. But for professional products, STM32 offers:

• Speed: A standard Arduino Uno runs at 16 MHz. An STM32F4 runs at 168 MHz.
• Debugging: With ST-Link, you can pause your code line-by-line and inspect variables in real-time. No more `Serial.print("I am here")`.
• Peripherals: DMA (Direct Memory Access) allows you to move data without waking up the CPU. This is magic for battery life.

Step 1: The Toolchain (STM32CubeIDE)

Forget installing 10 different tools. ST Microelectronics now provides STM32CubeIDE, which is an all-in-one software.

It includes a Device Configuration Tool (where you click on pins to set them as Input/Output) and the Code Editor itself. It writes the initialization code for you, so you don't have to memorize 500 registers.

Step 2: "Hello World" (Blinky)

Let’s replicate the classic Blink sketch.
1. Open CubeIDE and start a new project.
2. Select your chip (e.g., STM32F103C8 "Blue Pill").
3. Click on Pin PC13 in the diagram and set it to "GPIO_Output".
4. Hit "Generate Code" (The Gear Icon).

The Code

Head over to `main.c`. You will see a lot of auto-generated comments. Scroll down to the `while(1)` loop. This is your `loop()` function.

Add these two lines:

That’s it! `HAL_GPIO_TogglePin` is the professional equivalent of flipping a switch. `HAL_Delay` uses the system tick timer to pause.

Step 3: Flashing the Board

Connect your ST-Link V2 programmer to the board (3.3V, GND, SWDIO, SWCLK). Hit the green "Run" button in the IDE.

If the LED starts flashing, congratulations! You just ran your first Bare Metal ARM Cortex-M code. You are no longer just a maker; you are an embedded engineer.

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