# GPIO Digital ## CMSIS ### Tutorial Code: LED Toggle ```cpp /** ****************************************************************************** * @author SSSLAB * @Mod 2021-8-12 by YKKIM * @brief Embedded Controller: Tutorial Digital In * - Turn on LED LD2 while Button B1 is pressing * ****************************************************************************** */ // GPIO Mode : Input(00), Output(01), AlterFunc(10), Analog(11, reset) // GPIO Speed : Low speed (00), Medium speed (01), Fast speed (10), High speed (11) // GPIO Output Type: Output push-pull (0, reset), Output open drain (1) // GPIO Push-Pull : No pull-up, pull-down (00), Pull-up (01), Pull-down (10), Reserved (11) #include "stm32f4xx.h" #define LED_PIN 5 //LD2 #define BUTTON_PIN 13 void RCC_HSI_init(void); //defined in ecRcc.h void RCC_GPIOA_enable(void); void RCC_GPIOC_enable(void); int main(void) { /* Part 1. RCC GPIOA Register Setting */ RCC_GPIOA_enable(); RCC_GPIOC_enable(); /* Part 2. GPIO Register Setting for OUTPUT*/ // GPIO Mode Register GPIOA->MODER &= ~(3UL<<(2*LED_PIN)); // Clear '00' for Pin 5 GPIOA->MODER |= 1UL<<(2*LED_PIN); // Set '01' for Pin 5 // GPIO Output Type Register GPIOA->OTYPER &= ~(1UL<PUPDR &= ~(3UL<<(2*LED_PIN)); // 00: none // GPIO Output Speed Register GPIOA->OSPEEDR &= ~(3UL<<(2*LED_PIN)); GPIOA->OSPEEDR |= 2UL<<(2*LED_PIN); //10:Fast Speed /* Part 3. GPIO Register Setting for INPUT*/ // GPIO Mode Register GPIOC->MODER &= ~(3UL<<(2*BUTTON_PIN)); // 00: Input // GPIO Pull-Up/Pull-Down Register GPIOC->PUPDR &= ~(3UL<<(2*BUTTON_PIN)); GPIOC->PUPDR |= 2UL<<(2*BUTTON_PIN); // 10: Pull-down /* Part 4. Deal loop */ while(1){ unsigned int btVal=0; //Read bit value of Button btVal=(GPIOC->IDR) & (1UL << BUTTON_PIN); if(btVal == 0) GPIOA->ODR |= (1UL << LED_PIN); else GPIOA->ODR &= ~(1UL << LED_PIN); } } void RCC_GPIOA_enable() { // HSI is used as system clock RCC_HSI_init(); // RCC Peripheral Clock for GPIO_A Enable RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN; } void RCC_GPIOC_enable() { // HSI is used as system clock RCC_HSI_init(); // RCC Peripheral Clock for GPIO_A Enable RCC->AHB1ENR |= RCC_AHB1ENR_GPIOCEN; } void RCC_HSI_init() { // Enable High Speed Internal Clock (HSI = 16 MHz) RCC->CR |= ((uint32_t)RCC_CR_HSION); // wait until HSI is ready while ( (RCC->CR & (uint32_t) RCC_CR_HSIRDY) == 0 ) {;} // Select HSI as system clock source RCC->CFGR &= (uint32_t)(~RCC_CFGR_SW); RCC->CFGR |= (uint32_t)RCC_CFGR_SW_HSI; // Wait till HSI is used as system clock source while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != 0 ); } void bit_toggle(unsigned int pinNum){ GPIOA->ODR ^= 1<MODER &= ~(3UL<<(2*pin)); Port->MODER |= mode<<(2*pin); } ``` ### Example code for LAB: LED toggle Tutorial\_DigitalInOut\_LED\_Button\_HAL.c ```cpp /** ****************************************************************************** * @author SSSLAB * @Mod 2021-8-12 by YKKIM * @brief Embedded Controller: LAB Digital In/Out * - Toggle LED LD2 by Button B1 pressing * ****************************************************************************** */ #include "stm32f4xx.h" #include "myGPIO.h" #include "myRCC.h" #define LED_PIN 5 #define BUTTON_PIN 13 void setup(void); int main(void) { // Initialiization -------------------------------------------------------- setup(); // Inifinite Loop ---------------------------------------------------------- while(1){ if(GPIO_read(GPIOC, BUTTON_PIN) == 0) GPIO_write(GPIOA, LED_PIN, HIGH); else GPIO_write(GPIOA, LED_PIN, LOW); } } // Initialiization void setup(void) { RCC_HSI_init(); GPIO_init(GPIOC, BUTTON_PIN, INPUT); // calls RCC_GPIOC_enable() GPIO_init(GPIOA, LED_PIN, OUTPUT); // calls RCC_GPIOA_enable() } ``` ## Application API ### EC\_GPIO.h ```cpp #include "stm32f411xe.h" #include "ecGPIO.h" #include "ecRCC.h" #ifndef __EC_GPIO_API_H #define __EC_GPIO_API_H #define EC_DOUT 1 #define EC_DIN 0 #define EC_PU 1 #define EC_PD 0 #define EC_NONE 0 #define EC_LOW 0 #define EC_MEDIUM 1 #define EC_FAST 2 #define EC_HIGH 3 #define LED_PIN 5 #define BUTTON_PIN 13 /* System CLOCK is HSI by default */ class EC_DigitalIn { public: EC_DigitalIn(GPIO_TypeDef *Port, int pin) { uint8_t mode=EC_DIN; // mode=0 GPIO_init(Port, pin, mode); Port_t=Port; pin_t=pin; mode_t=mode; } ~EC_DigitalIn() { delete[] Port_t; } int read() { val_t=GPIO_read(Port_t, pin_t); return val_t; } void pupdr(int _pupd){ GPIO_pudr(Port_t, pin_t, _pupd); } operator int() { return read(); } private: GPIO_TypeDef *Port_t; int pin_t; int mode_t; int val_t; }; class EC_DigitalOut { public: EC_DigitalOut(GPIO_TypeDef *Port, int pin); // Exercise. Define the function in EC_GPIO.cpp ~EC_DigitalOut() { delete[] Port_t; } void write(int _outVal); // Exercise. Define the function in EC_GPIO.cpp void pupdr(int _pupd); // Exercise. Define the function in EC_GPIO.cpp void otype(int _type); // Exercise. Define the function in EC_GPIO.cpp void ospeed(int _speed); // Exercise. Define the function in EC_GPIO.cpp EC_DigitalOut &operator= (int value) { write(value); return *this; } int read() { return GPIO_read(Port_t, pin_t); } operator int() { // Underlying call is thread safe return read(); } private: GPIO_TypeDef *Port_t; int pin_t; int mode_t; }; #endif ``` ### EC\_GPIO.cpp ```cpp #include "EC_GPIO.h" /* System CLOCK is HSI by default */ EC_DigitalOut::EC_DigitalOut(GPIO_TypeDef *Port, int pin) { uint8_t mode=EC_DOUT; // mode=1; GPIO_init(Port, pin, mode); this->Port_t=Port; this->pin_t=pin; this->mode_t=mode; } void EC_DigitalOut::write(int _outVal) { GPIO_write(Port_t, pin_t, _outVal); } void EC_DigitalOut::pupdr(int _pupd){ GPIO_pudr(Port_t, pin_t, _pupd); } void EC_DigitalOut::otype(int _type){ GPIO_otype(Port_t, pin_t, _type); } void EC_DigitalOut::ospeed(int _speed){ GPIO_ospeed(Port_t, pin_t, _speed); } ``` ### Example code for LAB: LED toggle Tutorial\_DigitalInOut\_LED\_Button\_API. ```cpp /** ****************************************************************************** * @author SSSLAB * @Mod 2021-8-12 by YKKIM * @brief Embedded Controller: LAB Digital In/Out with API * - Toggle LED LD2 by Button B1 pressing * ****************************************************************************** */ #include "EC_GPIO.h" #define LED_PIN 5 #define BUTTON_PIN 13 EC_DigitalIn button(GPIOC,BUTTON_PIN); EC_DigitalOut led(GPIOA,LED_PIN); int main(void) { // Initialiization -------------------------------------------------------- // Inifinite Loop ---------------------------------------------------------- while(1){ //if(button.read() == 0) led.write(HIGH); //else led.write(LOW); if(!button) led=1; else led=0; } } ``` ### mbed {% tabs %} {% tab title="mbed" %} ```cpp #include "mbed.h" DigitalIn button(USER_BUTTON); DigitalOut led(LED1); int main() { while(1) { if(!button) led = 1; else led = 0; } } ``` {% endtab %} {% endtabs %} --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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