【AT-START-L021测评】硬件SPI驱动TFT屏
#技术资源# 本帖介绍用AT32L021的spi2硬件驱动tft屏，使用的是屏幕是大越创新1.8寸的160*128屏幕。接口为与AT32L021通信用到了SDI SCL CS RS这四根线，因为单片机做主，tft屏幕做从设备，故SDO不用输出，可不接，单片机工作在半双工模式，其具体接线如图：
软件部分：
我们要配置两部分，一部分是硬件IO的配置，使用了硬件spi2，那么就要启用该功能，配置如下
gpio_init_type gpio_initstructure;
spi_init_type spi_init_struct;
crm_periph_clock_enable(CRM_GPIOB_PERIPH_CLOCK, TRUE);
crm_periph_clock_enable(CRM_GPIOA_PERIPH_CLOCK, TRUE);
//crm_periph_clock_enable(CRM_DMA1_PERIPH_CLOCK, TRUE);
//gpio_pin_mux_config(GPIOA, GPIO_PINS_SOURCE8, GPIO_MUX_0);
//gpio_pin_mux_config(GPIOA, GPIO_PINS_SOURCE9, GPIO_MUX_0);
gpio_pin_mux_config(GPIOB, GPIO_PINS_SOURCE12, GPIO_MUX_0);
gpio_pin_mux_config(GPIOB, GPIO_PINS_SOURCE13, GPIO_MUX_0);
gpio_pin_mux_config(GPIOB, GPIO_PINS_SOURCE15, GPIO_MUX_0);
/* software cs, pb12 as a general io to control flash cs */
gpio_initstructure.gpio_out_type = GPIO_OUTPUT_PUSH_PULL;
gpio_initstructure.gpio_pull = GPIO_PULL_UP;
gpio_initstructure.gpio_mode = GPIO_MODE_OUTPUT;
gpio_initstructure.gpio_drive_strength = GPIO_DRIVE_STRENGTH_STRONGER;
gpio_initstructure.gpio_pins = GPIO_PINS_12;
gpio_init(GPIOB, &gpio_initstructure);
/* sck */
gpio_initstructure.gpio_pull = GPIO_PULL_UP;
gpio_initstructure.gpio_mode = GPIO_MODE_MUX;
gpio_initstructure.gpio_pins = GPIO_PINS_13;
gpio_init(GPIOB, &gpio_initstructure);
/* miso */
//gpio_initstructure.gpio_pull = GPIO_PULL_UP;
//gpio_initstructure.gpio_mode = GPIO_MODE_MUX;
//gpio_initstructure.gpio_pins = GPIO_PINS_14;
//gpio_init(GPIOB, &gpio_initstructure);
/* mosi */
gpio_initstructure.gpio_pull = GPIO_PULL_UP;
gpio_initstructure.gpio_mode = GPIO_MODE_MUX;
gpio_initstructure.gpio_pins = GPIO_PINS_15;
gpio_init(GPIOB, &gpio_initstructure);
/* dc */
gpio_initstructure.gpio_out_type = GPIO_OUTPUT_PUSH_PULL;
gpio_initstructure.gpio_pull = GPIO_PULL_UP;
gpio_initstructure.gpio_mode = GPIO_MODE_OUTPUT;
gpio_initstructure.gpio_drive_strength = GPIO_DRIVE_STRENGTH_STRONGER;
gpio_initstructure.gpio_pins = GPIO_PINS_8;
gpio_init(GPIOA, &gpio_initstructure);
/* blk */
gpio_initstructure.gpio_out_type = GPIO_OUTPUT_PUSH_PULL;
gpio_initstructure.gpio_pull = GPIO_PULL_UP;
gpio_initstructure.gpio_mode = GPIO_MODE_OUTPUT;
gpio_initstructure.gpio_drive_strength = GPIO_DRIVE_STRENGTH_STRONGER;
gpio_initstructure.gpio_pins = GPIO_PINS_9;
gpio_init(GPIOA, &gpio_initstructure);以上是配置IO，第二步，我们要配置spi的具体参数，如下：
crm_periph_clock_enable(CRM_SPI2_PERIPH_CLOCK, TRUE);
spi_default_para_init(&spi_init_struct);
spi_init_struct.transmission_mode = SPI_TRANSMIT_HALF_DUPLEX_TX;
spi_init_struct.master_slave_mode = SPI_MODE_MASTER;
spi_init_struct.mclk_freq_division = SPI_MCLK_DIV_2;
spi_init_struct.first_bit_transmission = SPI_FIRST_BIT_MSB;
spi_init_struct.frame_bit_num = SPI_FRAME_8BIT;
spi_init_struct.clock_polarity = SPI_CLOCK_POLARITY_HIGH;
spi_init_struct.clock_phase = SPI_CLOCK_PHASE_2EDGE;
spi_init_struct.cs_mode_selection = SPI_CS_SOFTWARE_MODE;
spi_init(SPI2, &spi_init_struct);
spi_enable(SPI2, TRUE);其中有配置时钟，模式，分频，帧模式，cs模式，传输位等。配置成功后，我们就可以进行对tft进行初始化控制，主要是用到单片机的spi硬件发送函数。
uint8_t spi_byte_write(uint8_t data)
{
spi_i2s_data_transmit(SPI2, data);
while(spi_i2s_flag_get(SPI2, SPI_I2S_TDBE_FLAG) == RESET);
return 0;
}我们直接用库函数里的作为写tft的寄存器函数。其初始化如下：
LCD_WR_REG(0x11); //Sleep exit
delay_ms(120); // delay 120 ms
//ST7735R Frame Rate
LCD_WR_REG(0xB1);
LCD_WR_DATA8(0x05);
LCD_WR_DATA8(0x3C);
LCD_WR_DATA8(0x3C);
LCD_WR_REG(0xB2);
LCD_WR_DATA8(0x05);
LCD_WR_DATA8(0x3C);
LCD_WR_DATA8(0x3C);
LCD_WR_REG(0xB3);
LCD_WR_DATA8(0x05);
LCD_WR_DATA8(0x3C);
LCD_WR_DATA8(0x3C);
LCD_WR_DATA8(0x05);
LCD_WR_DATA8(0x3C);
LCD_WR_DATA8(0x3C);
//------------------------------------End ST7735S Frame Rate---------------------------------//
LCD_WR_REG(0xB4); //Dot inversion
LCD_WR_DATA8(0x03);
//------------------------------------ST7735S Power Sequence---------------------------------//
LCD_WR_REG(0xC0);
LCD_WR_DATA8(0x28);
LCD_WR_DATA8(0x08);
LCD_WR_DATA8(0x04);
LCD_WR_REG(0xC1);
LCD_WR_DATA8(0XC0);
LCD_WR_REG(0xC2);
LCD_WR_DATA8(0x0D);
LCD_WR_DATA8(0x00);
LCD_WR_REG(0xC3);
LCD_WR_DATA8(0x8D);
LCD_WR_DATA8(0x2A);
LCD_WR_REG(0xC4);
LCD_WR_DATA8(0x8D);
LCD_WR_DATA8(0xEE);
//---------------------------------End ST7735S Power Sequence-------------------------------------//
LCD_WR_REG(0xC5); //VCOM
LCD_WR_DATA8(0x1A);
LCD_WR_REG(0x36); //MX, MY, RGB mode
LCD_WR_DATA8(0xC0);
//------------------------------------ST7735S Gamma Sequence---------------------------------//
LCD_WR_REG(0xE0);
LCD_WR_DATA8(0x04);
LCD_WR_DATA8(0x22);
LCD_WR_DATA8(0x07);
LCD_WR_DATA8(0x0A);
LCD_WR_DATA8(0x2E);
LCD_WR_DATA8(0x30);
LCD_WR_DATA8(0x25);
LCD_WR_DATA8(0x2A);
LCD_WR_DATA8(0x28);
LCD_WR_DATA8(0x26);
LCD_WR_DATA8(0x2E);
LCD_WR_DATA8(0x3A);
LCD_WR_DATA8(0x00);
LCD_WR_DATA8(0x01);
LCD_WR_DATA8(0x03);
LCD_WR_DATA8(0x13);
LCD_WR_REG(0xE1);
LCD_WR_DATA8(0x04);
LCD_WR_DATA8(0x16);
LCD_WR_DATA8(0x06);
LCD_WR_DATA8(0x0D);
LCD_WR_DATA8(0x2D);
LCD_WR_DATA8(0x26);
LCD_WR_DATA8(0x23);
LCD_WR_DATA8(0x27);
LCD_WR_DATA8(0x27);
LCD_WR_DATA8(0x25);
LCD_WR_DATA8(0x2D);
LCD_WR_DATA8(0x3B);
LCD_WR_DATA8(0x00);
LCD_WR_DATA8(0x01);
LCD_WR_DATA8(0x04);
LCD_WR_DATA8(0x13);
//------------------------------------End ST7735S Gamma Sequence-----------------------------//
LCD_WR_REG(0x3A); //65k mode
LCD_WR_DATA8(0x05);
LCD_WR_REG(0x29); //Display on
LCD_Display_Dir(LCD_DIR_Mode); //选择--屏幕显示方式
//LCD_BLK_On; //点亮背光
LCD_Clear(WHITE);初始化后，进行对屏幕字符串的输出：
LCD_ShowString(0,0,120,16,12,BLUE,"abc");
LCD_ShowString(0,16,120,16,12,BLUE,"AT32L021-TEST");
LCD_ShowString(0,32,120,16,12,BLUE,"HARDWARE-SPI-TFT");实际效果如下：
显示图片啥的来一个
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