braids_displaytest.c

#include "stm32f10x.h"

const uint16_t kPinClk = GPIO_Pin_11;
const uint16_t kPinEnable = GPIO_Pin_10;
const uint16_t kPinData = GPIO_Pin_1;

const uint16_t kCharacterEnablePins[] = {
		GPIO_Pin_5,
		GPIO_Pin_6,
		GPIO_Pin_7,
		GPIO_Pin_8
};

void Init() {
	  RCC_APB2PeriphClockCmd(
	      RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC |
	      RCC_APB2Periph_TIM1 | RCC_APB2Periph_SPI1 | RCC_APB2Periph_USART1 |
		  RCC_APB2Periph_ADC1, ENABLE);
	  RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE); // for dac


	GPIO_InitTypeDef gpio_init;
	gpio_init.GPIO_Pin = kPinClk;
	gpio_init.GPIO_Pin |= kPinEnable;
	gpio_init.GPIO_Pin |= kPinData;
	gpio_init.GPIO_Pin |= kCharacterEnablePins[0];
	gpio_init.GPIO_Pin |= kCharacterEnablePins[1];
	gpio_init.GPIO_Pin |= kCharacterEnablePins[2];
	gpio_init.GPIO_Pin |= kCharacterEnablePins[3];

	gpio_init.GPIO_Speed = GPIO_Speed_50MHz;
	gpio_init.GPIO_Mode = GPIO_Mode_Out_PP;
	GPIO_Init(GPIOB, &gpio_init);

	GPIOB->BSRR = kPinEnable;
	GPIOB->BSRR = kCharacterEnablePins[0];
	GPIOB->BSRR = kCharacterEnablePins[1];
	GPIOB->BSRR = kCharacterEnablePins[2];
	GPIOB->BSRR = kCharacterEnablePins[3];
}


void Shift14SegmentsWord(uint16_t data) {
	GPIOB->BRR = kPinEnable;
	for (uint16_t i = 0; i < 16; ++i) {
		GPIOB->BRR = kPinClk;
		if (data & 1) {
			GPIOB->BSRR = kPinData;
		} else {
			GPIOB->BRR = kPinData;
		}
		data >>= 1;
		GPIOB->BSRR = kPinClk;
	}
	GPIOB->BSRR = kPinEnable;
}

const uint8_t kDisplayWidth = 4;
const uint8_t kBrightnessLevels = 4;

uint16_t active_position_;
uint16_t brightness_pwm_cycle_;
uint16_t brightness_ = 3;

int main(void)
{
	Init();

	int t;
	while(t++) {
		uint16_t bbval = ((t << 1) ^ ((t << 1) + (t >> 7) & t >> 12)) | t >> (4 - (1 ^ 7 & (t >> 15))) | t >> 7;
		Shift14SegmentsWord((uint16_t)bbval);
	}

}