极海APM32F407IG Tiny Board开发板测评5：UART通讯+SPI驱动LCD12864+I2C读取D

极海APM32F407IG Tiny Board开发板测评4：按键+定时器测试  对极海APM32F407IG Tiny Board开发板进行了按键+定时器测试，本文将就UART通讯+SPI驱动LCD12864+I2C读取D展开测试。

5.极海APM32F407IG Tiny Board开发板测评：UART通讯+SPI驱动LCD12864+I2C读取DHTC12温湿度

5.1UART串口通讯

UART在嵌入式领域应用的非常广泛，APM32F407拥有4个USART和2个UART，板子上引出的串口时USART1 TX:PA9 RX:PA10

简单做一个将接收到的数据原样返回的程序，代码示例

#include "Board_APM32F407_TINY.h"

#include "bsp_delay.h"

#include "apm32f4xx_tmr.h"

#define UART_BUFFER_LEN 30

uint8_t uart_buffer[UART_BUFFER_LEN] = {0};

uint8_t uart_rxindex = 0;

uint8_t uart_rxlen = 0;

uint8_t uart_txindex = 0;

uint8_t uart_txlen = 0;

void uart_init()

{

    USART_Config_T usartConfigStruct;

    usartConfigStruct.baudRate = 115200;

    usartConfigStruct.hardwareFlow = USART_HARDWARE_FLOW_NONE;

    usartConfigStruct.mode = USART_MODE_TX_RX;

    usartConfigStruct.parity = USART_PARITY_NONE;

    usartConfigStruct.stopBits = USART_STOP_BIT_1;

    usartConfigStruct.wordLength = USART_WORD_LEN_8B;

    APM_TINY_COMInit(COM1, &usartConfigStruct);

    USART_EnableInterrupt(TINY_COM1, USART_INT_RXBNE);

    USART_EnableInterrupt(TINY_COM1, USART_INT_IDLE);

    USART_ClearStatusFlag(TINY_COM1, USART_FLAG_RXBNE);

    NVIC_EnableIRQRequest(TINY_COM1_IRQn,0,0);

}

void readrxtotxbuffer()

{

    uart_txlen += uart_rxlen;

    uart_rxlen = 0;

    USART_EnableInterrupt(TINY_COM1, USART_INT_TXBE);

}

int main(void)

{

    APM_DelayInit();

    uart_init();

    while (1)

    {

    }

}

void SysTick_Handler(void)

{

    APM_DelayTickDec();

}

void USART1_IRQHandler(void)

{

    if(USART_ReadStatusFlag(TINY_COM1, USART_FLAG_RXBNE) == SET){

        uart_buffer[uart_rxindex++] = (uint8_t)USART_RxData(TINY_COM1);

        if(uart_rxindex == UART_BUFFER_LEN)

            uart_rxindex = 0;

        uart_rxlen++;

    }

    if(USART_ReadStatusFlag(TINY_COM1, USART_FLAG_IDLE) == SET|| uart_rxlen == 10) {

        USART_ClearStatusFlag(TINY_COM1, USART_FLAG_IDLE);

        readrxtotxbuffer();

    }

    if(USART_ReadStatusFlag(TINY_COM1, USART_FLAG_TXBE) == SET){

        if(uart_txlen > 0)

        {

            USART_TxData(TINY_COM1,uart_buffer[uart_txindex++]);

            if(uart_txindex == UART_BUFFER_LEN)

                uart_txindex = 0;

            uart_txlen--;

        }

        else

        {

            USART_DisableInterrupt(TINY_COM1, USART_INT_TXBE);

        }

    }

}

编译烧录查看效果
板子上的Geehy LINK没有串口功能，还要额外找个USB转串口工具测试，按顺序连接好串口接线

SPI驱动12864LCD
SPI是一种高速的全双工同步的通信总线，需要至少SCK MOSI MISO三根线实现数据双向传输，可以通过片选线来实现对不同设备的访问。

APM32F407拥有3个SPI，手上有个12864的LCD屏，用SPI驱动的，尝试用这块板子点亮一下。通讯需要用到5个IO:SCK MOSI CS RST A0都是输出模式，SCK用PA5 MOSI用PA7，其它的就随意了。

数据是单向传输的因此SPI配置成仅发送就行了，代码示例

#include "Board_APM32F407_TINY.h"

#include "bsp_delay.h"

#include "apm32f4xx_tmr.h"

#include "apm32f4xx_spi.h"

#include "yuyy_project_config.h"

#include "yuyy_hs12864g18b.h"

Yuyy_Hs12864g18b_Gpio_Config_t hs12864g18b_gpio_config;

void hs12864g18b_init()

{

    GPIO_Config_T GPIO_InitStructure;

    SPI_Config_T  SPI1_InitStructure;

    RCM_EnableAHB1PeriphClock (RCM_AHB1_PERIPH_GPIOA);

    RCM_EnableAPB2PeriphClock(RCM_APB2_PERIPH_SPI1);

    RCM_EnableAPB2PeriphClock(RCM_APB2_PERIPH_SYSCFG);

    hs12864g18b_gpio_config.cs.gpio = GPIOA;

    hs12864g18b_gpio_config.cs.pin = GPIO_PIN_3;

    hs12864g18b_gpio_config.rst.gpio = GPIOA;

    hs12864g18b_gpio_config.rst.pin = GPIO_PIN_4;

    hs12864g18b_gpio_config.a0.gpio = GPIOA;

    hs12864g18b_gpio_config.a0.pin = GPIO_PIN_6;

    hs12864g18b_gpio_config.sck.gpio = GPIOA;

    hs12864g18b_gpio_config.sck.pin = GPIO_PIN_5;

    hs12864g18b_gpio_config.mo.gpio = GPIOA;

    hs12864g18b_gpio_config.mo.pin = GPIO_PIN_7;

    GPIO_ConfigStructInit(&GPIO_InitStructure);

    GPIO_InitStructure.pin = GPIO_PIN_3 | GPIO_PIN_4 | GPIO_PIN_6;

    GPIO_InitStructure.speed = GPIO_SPEED_100MHz;

    GPIO_InitStructure.mode = GPIO_MODE_OUT;

    GPIO_InitStructure.otype = GPIO_OTYPE_PP;

    GPIO_InitStructure.pupd = GPIO_PUPD_NOPULL;

    GPIO_Config(GPIOA, &GPIO_InitStructure);

    #if(YUYY_HS12864G18B_USE_SOFT_SPI)

    GPIO_InitStructure.pin = GPIO_PIN_5 | GPIO_PIN_7;

    GPIO_InitStructure.mode = GPIO_MODE_OUT;

    GPIO_Config(GPIOA, &GPIO_InitStructure);

    yuyy_hs12864g18b_set_spigpio(NULL,&hs12864g18b_gpio_config);

    #else

    GPIO_ConfigPinAF(GPIOA, GPIO_PIN_SOURCE_5, GPIO_AF_SPI1);

    GPIO_ConfigPinAF(GPIOA, GPIO_PIN_SOURCE_7, GPIO_AF_SPI1);

    GPIO_InitStructure.pin = GPIO_PIN_5 | GPIO_PIN_7;

    GPIO_InitStructure.mode = GPIO_MODE_AF;

    GPIO_Config(GPIOA, &GPIO_InitStructure);

    SPI_ConfigStructInit(&SPI1_InitStructure);

    SPI1_InitStructure.direction = SPI_DIRECTION_1LINE_TX; //只需要发送

    SPI1_InitStructure.mode = SPI_MODE_MASTER;

    SPI1_InitStructure.length = SPI_DATA_LENGTH_8B;        //数据长度8bit

    SPI1_InitStructure.polarity = SPI_CLKPOL_HIGH;         //空闲时SCK高电平

    SPI1_InitStructure.phase = SPI_CLKPHA_2EDGE;           //第二个边沿采样

    SPI1_InitStructure.nss = SPI_NSS_SOFT;                 //软件控制片选

    SPI1_InitStructure.baudrateDiv = SPI_BAUDRATE_DIV_8;   //时钟分频系数

    SPI1_InitStructure.firstBit = SPI_FIRSTBIT_MSB;

    SPI_Config(SPI1, &SPI1_InitStructure);

    SPI_DisableCRC(SPI1);

    SPI_Enable(SPI1);

    yuyy_hs12864g18b_set_spigpio(SPI1,&hs12864g18b_gpio_config);

    #endif

    yuyy_hs12864g18b_init();

    yuyy_hs12864g18b_clear_screen();

}

void yuyy_hard_spi_writebyte(YUYY_SPI_TYPE spix,uint8_t dat)

{

    while (SPI_I2S_ReadStatusFlag(spix, SPI_FLAG_TXBE) == RESET);

    SPI_I2S_TxData(spix, dat);

}

int main(void)

{

    APM_DelayInit();

    hs12864g18b_init();

    yuyy_hs12864g18b_display_string_8x16(0,0,0,(uint8_t *)"APM32F407IG TEST");

    yuyy_hs12864g18b_display_string_8x16(0,2,0,(uint8_t *)"Tiny Board v1.0");

    yuyy_hs12864g18b_display_string_8x16(0,4,0,(uint8_t *)"Code by yuyy1989");

    while (1)

    {

    }

}

void SysTick_Handler(void)

{

    APM_DelayTickDec();

}

编译烧录查看效果

I2C读取DHTC12温湿度
I2C属于两线式串行总线，属于一主多从的总线结构，总线上的每个设备都有一个特定的设备地址，以区分同一I2C总线上的其他设备。APM32F407拥有3个I2C，很多传感器都是用I2C进行通讯的，接下来尝试用I2C读取DHTC12温湿度，选用PF0 PF1。

尝试用硬件I2C，结果在调用I2C_EnableGenerateStart后无论等多久I2C_ReadEventStatus(iicx, I2C_EVENT_MASTER_MODE_SELECT)返回的都是0。想参考bsp_i2c.c的驱动代码，结果用的是软件I2C，索性直接用软件I2C了，通讯代码可以直接参考bsp_i2c.c。

运行效果