If you have a software programming background you are used to do a Hello World code as your first program to test your setup. When it comes to hardware it's more common to make a LED blink.
Let's go, open up STM32CubeIDE if you haven't already, and you should be greeted with the folllowing window:
This workspace is where your projects will be stored, you can see a workspace as a group of projects. For example, it is a good idea to have a workspace for all the projects of this workshop.
Then the welcome page will show up:
Click on Start new STM32 project and you will be preseted with a powerfull tool to help you pick the microcontroller you need.
You can filter by the number of pins you need, number of SPI, UART, a lot of other interfaces and hardware features. In this case we have already done this for you and we gave you a STM32F103C8. You can search for it on the search bar on the upper left and click Next.
Then you can give the project a name and click Finish.
It will ask you if you want to open STM32CubeMx perspective, it is recommended that you check Remember my decision and then click Yes to see the STM32F103C8 in all its glory.
If all went ok you will see this screen:
This is were you do all the peripheral configurations, you can do it in the code but here you can see all the options check if your configurations are ok. Here you can for example turn an analog pin on and set its sampling time, and if you have two analog signals you can configure to sample the first signal 10 times per second and the second one 2 times per second. This lets you give priorities to the analog signals you have. Impressed?!
Now let's learn to walk before we can run. Let's try to make the LED already included in the STM32 blink. As you an see in the board the LED has the following marking PC13 next to it.
This means it is connected to pin PC13 of the microcontroller, so you should set this pin as an output pin. You can do that by left clicking the PC13 pin and select GPIO_Output.
Then hit save and say Yes when you are propmted to generate code. Like before, we recommend checking Remember my decision.
Then on the left open the main.c file that can be found at:
Whoaaa! There's a lot going on here already! Yes, STM32CubeMX, the tool you selected the pin as output, generates (the boring to write) code for you. Because of that you need to be careful where to write your own code since there are chucks of code that belong to STM32CubeMX and those chunks are overwrited every time you change anything in STM32CubeMX. This means you have be be extra careful to always write your code between BEGIN and END comment statements. If you do that your code will stay safe.
Here it is an excerpt of code that has two bounding boxes for you to write code. Each one has different titles, for different ends.
#include "main.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */Hmmm, ok, but what code was generated when you have set PC13 as output? Let's see.
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOC_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_13, GPIO_PIN_RESET);
/*Configure GPIO pin : PC13 */
GPIO_InitStruct.Pin = GPIO_PIN_13;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
}Even a simple IO pin has some configurations to be done. It can be seen that the default state for the LED is OFF because its state was set to GPIO_PIN_RESET. Other interesting thing to note is that you can set an internal pull-up or pull-down by setting GPIO_InitStruct.Pull to GPIO_PULLUP or GPIO_PULLDOWN. You can also configure the GPIO to be push-pull or an open-drain by setting GPIO_InitStruct.Mode.
Here it comes the part we've all waiting for, let's make the LED blink! Search for the while (1) instruction and then use the same function present in the initialization routine to blink the LED. Be sure to put your code between BEGIN and END statements otherwise it will be thrown away later on.
Tip: You can use the HAL_Delay(uint32_t Delay) function to wait for a given time in milliseconds. And use CTRL + SPACE to complete code.