diff options
| -rw-r--r-- | src/main.c | 61 |
1 files changed, 43 insertions, 18 deletions
@@ -1,12 +1,21 @@ #include "stm32f0xx.h" -#define PINOUT_LED_1 3 -#define PINOUT_LED_2 5 -#define PINOUT_LED_3 4 -#define PINOUT_LED_4 6 +// GPIO A +#define PINOUT_DISP_CLK (5) +#define PINOUT_DISP_DIO (6) +#define PINOUT_POT (7) + +// GPIO B +#define PINOUT_LED_1 (3) +#define PINOUT_LED_2 (5) +#define PINOUT_LED_3 (4) +#define PINOUT_LED_4 (6) const unsigned short leds[] = {PINOUT_LED_1, PINOUT_LED_2, PINOUT_LED_3, PINOUT_LED_4}; +#define PINOUT_BTN (8) + + /* * This function configures the I/O-ports that are used by the I/O-shield. It * uses register RCC_AHBENR to enable the clocks for the ports that are used, @@ -14,18 +23,30 @@ const unsigned short leds[] = {PINOUT_LED_1, PINOUT_LED_2, PINOUT_LED_3, PINOUT_ * GPIOx_PUPDR to configure pull-up and pull-down resistors. */ void shieldConfig() { - // enable clock for I/O port D + // enable clock for I/O ports A and B RCC->AHBENR |= RCC_AHBENR_GPIOBEN; + // clear mode register configuration bits GPIOB->MODER &= ~((0b11 << (PINOUT_LED_1 * 2)) |\ (0b11 << (PINOUT_LED_2 * 2)) |\ (0b11 << (PINOUT_LED_3 * 2)) |\ - (0b11 << (PINOUT_LED_4 * 2))); + (0b11 << (PINOUT_LED_4 * 2)) |\ + (0b11 << (PINOUT_BTN * 2))); + // set output mode register configuration bits + // 0b00 -> input mode (reset state) + // 0b01 -> general purpose output mode + // 0b10 -> alternate function mode + // 0b11 -> analog mode GPIOB->MODER |= (0b01 << (PINOUT_LED_1 * 2)) |\ (0b01 << (PINOUT_LED_2 * 2)) |\ (0b01 << (PINOUT_LED_3 * 2)) |\ - (0b01 << (PINOUT_LED_4 * 2)); + (0b01 << (PINOUT_LED_4 * 2)) |\ + (0b00 << (PINOUT_BTN * 2)); + + // pull-up resistor for button + GPIOB->PUPDR &= ~(0b11 << (PINOUT_BTN * 2)); + GPIOB->PUPDR |= (0b01 << (PINOUT_BTN * 2)); } /* @@ -44,7 +65,7 @@ void ledWrite(int num, int on) { * value 0 indicates that the button is currently not pressed. */ int buttonRead() { - return 0; + return (GPIOB->IDR & (1 << PINOUT_BTN)) > 0; } void delay() @@ -55,22 +76,26 @@ void delay() asm("nop"); } } + +int mod(int a, int b) { + int m = a % b; + return m < 0 ? (b < 0) ? m - b : m + b : m; +} + int main() { shieldConfig(); - // RCC->AHBENR |= RCC_AHBENR_GPIOAEN; - // GPIOA->MODER &= ~(1 << (PINOUT_LED_1 * 2 + 1)); - // GPIOA->MODER |= (1 << (PINOUT_LED_1 * 2)); - - // GPIOA_MODER &= ~(0 << (PINOUT_LED_1 * 2 + 1)); - + uint8_t reverse = 0; + uint8_t led = 0; while (1) { - for(int i = 0; i < 2 * 4; i++) { - ledWrite(i % 4, i >= 4); + reverse = buttonRead(); + for(int j = 0; j < 4; j++) ledWrite(j, 0); + + led = mod(led + ((2 * reverse) - 1), 4); - delay(); - } + ledWrite(led, 1); + delay(); } } |