本篇文章来自极术社区与兆易创新组织的GD32F427开发板评测活动，更多开发板试用活动请关注极术社区网站。作者：小蜗牛

一、硬件介绍

讯享网

USR-C210 硬件上集成了 MAC、基频芯片、射频收发单元，尺寸小，易于焊接在客户的单板电路上，且模块可选择内置或外置天线的应用，方便客户多重选择，模块内置低功耗运行机制，可以有效实现模块的低功耗运行。

GD32F427系列高性能MCU产品系列提供了丰富的外设和大存储容量，可广泛应用于高级计算，云服务器，人工智能、工业控制、电机变频、图形显示、安防监控、传感器网络、无人机、机器人、物联网等创新领域。

二、硬件连接

从图中可以看到，只需将GD32F427开发板上的3.3V供给模块，然后UART口与WIFI模块连接，最后再使用一个GPIO作为WIFI模块的重启和复位控制，即可实现该模块完整控制。

三、程序初始化

本文使用USART3与WIFI模块进行连接，因此将对该部分进行初始化。
`void USART3_GpioInit(void)
{

/* enable GPIO clock */ rcu_periph_clock_enable(BSP_USART3_GPIO_RCU); /* configure the USART0 TX pin and USART0 RX pin */ gpio_af_set(BSP_USART3_TX_PORT, GPIO_AF_7, BSP_USART3_TX_PIN); gpio_af_set(BSP_USART3_RX_PORT, GPIO_AF_7, BSP_USART3_RX_PIN); /* configure USART0 TX as alternate function push-pull */ gpio_mode_set(BSP_USART3_TX_PORT, GPIO_MODE_AF, GPIO_PUPD_PULLUP, BSP_USART3_TX_PIN); gpio_output_options_set(BSP_USART3_TX_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, BSP_USART3_TX_PIN); /* configure USART0 RX as alternate function push-pull */ gpio_mode_set(BSP_USART3_RX_PORT, GPIO_MODE_AF, GPIO_PUPD_PULLUP, BSP_USART3_RX_PIN); gpio_output_options_set(BSP_USART3_RX_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, BSP_USART3_RX_PIN); 

} 串口波特率配置函数： void USART3_BoudRateConfig(uint32_t boud)
{

讯享网/* enable USART clock */ rcu_periph_clock_enable(BSP_USART3_RCU); /* USART configure */ usart_deinit(BSP_USART3_USART); usart_baudrate_set(BSP_USART3_USART, boud); usart_receive_config(BSP_USART3_USART, USART_RECEIVE_ENABLE); usart_transmit_config(BSP_USART3_USART, USART_TRANSMIT_ENABLE); usart_enable(BSP_USART3_USART); 

} Wifi模块初始化 void USRC210_Init(void)
{

uint8_t strBuf[200]; uint8_t i,status; while(1) { i=0; status=1; //1. Reset the UsrC210 Wifi_Reset(); //2.1 Send +++ Wake UsrC210 if(UsrC210SendCmd("+++")!=3) { continue; } //2.2 Send a Wake UsrC210 Into CMD Mode if(UsrC210SendCmd("a")!=1) { continue; } //3. Set WIFI Mode while(UsrC210SendCmd("AT+WMODE=APSTA\r\n")!=1) { if(i++>CmdRepeatCount) { status=0; break; } } if(!status)continue; //4. Set STA i=0; sprintf((char*)strBuf,"AT+WSTA=%s\r\n",STAMSG); while(UsrC210SendCmd((char*)strBuf)!=1) { if(i++>CmdRepeatCount) { status=0; break; } } if(!status)continue; //5. Set AP i=0; sprintf((char*)strBuf,"AT+WAP=%s\r\n",APMSG); while(UsrC210SendCmd((char*)strBuf)!=1) { if(i++>CmdRepeatCount) { status=0; break; } } if(!status)continue; //6. Set WEB LOGIN i=0; sprintf((char*)strBuf,"AT+WEBU=%s\r\n",LOGINMSG); while(UsrC210SendCmd((char*)strBuf)!=1) { if(i++>CmdRepeatCount) { status=0; break; } } if(!status)continue; //7. Set MID i=0; sprintf((char*)strBuf,"AT+MID=%s\r\n",MID); while(UsrC210SendCmd((char*)strBuf)!=1) { if(i++>CmdRepeatCount) { status=0; break; } } if(!status)continue; //8. SET TCP CLIENT i=0; sprintf((char*)strBuf,"AT+SOCKA=%s\r\n",SERVERMSG); while(UsrC210SendCmd((char*)strBuf)!=1) { if(i++>CmdRepeatCount) { status=0; break; } } if(!status)continue; //9. Reset The UsrC210 i=0; while(UsrC210SendCmd("AT+Z\r\n")!=1) { if(i++>CmdRepeatCount) { status=0; break; } } if(!status)continue; else { delay_ms(5000); break; } } 

} 在Wifi模块初始化中，需要定义一些参数，这样初始化后的模块就能拥有连接到以太网的信息。 uint8_t STAMSG[60]=“CMCC-sct3,45mnbqdb”; //连接的网络名字和密码

uint8_t APMSG[40]=“WG-0001,WG”;//模块作为AP的名字和密码

uint8_t LOGINMSG[40]=“WG-0001,WG”;//登录模块的名字和密码

uint8_t SERVERMSG[72]=“TCPC,47.103.12.149,8181”;//远程服务器端口
uint8_t ServerName[20]=“test.usr.cn,80”; //可以随便配置
uint8_t UrlName[12]=“/1.php[3F]”;

char OKMSG[4]={0x10,0xAA,0xBB,0xCC};//接收到正确信号返回信息
char PLSMSG[4]={0x10,0xCC,0xDD,0xEE};//发送心跳信号，如每秒连接
char RESMSG[4]={0xFF,0xFF,0xFF,0xFF};//返回保留信息`

四、定义通信协议

协议解析代码
`void Decode_Packet(void)
{

讯享网u8 packet_len; u8 relay_status[4]; u16 crc_get, crc_cal; if(UartRecvMessage()) { packet_len = uart1receBuf[0]; if(packet_len==0x10) { crc_get = uart1receBuf[packet_len - 2]; crc_get = (crc_get<< 8) | uart1receBuf[packet_len -1]; crc_cal = crc16(uart1receBuf,packet_len-2); if(crc_get!=crc_cal) { return; } else { ic_address=uart1receBuf[1]; R=uart1receBuf[2]; B=uart1receBuf[3]; G=uart1receBuf[4]; W=uart1receBuf[5]; relay_status[0] = uart1receBuf[6]; relay_status[1] = uart1receBuf[7]; relay_status[2] = uart1receBuf[8]; relay_status[3] = uart1receBuf[9]; reserved_data = (uart1receBuf[10]<<24)|(uart1receBuf[11]<<16)|(uart1receBuf[12]<<8)|(uart1receBuf[13]); DMX512_Buf_Init(0xf0); Update_Led(); LedFlag = 1; Relay_Operation(1,relay_status[0]); Relay_Operation(2,relay_status[0]); Relay_Operation(3,relay_status[0]); Relay_Operation(4,relay_status[0]); SendOK(); } } UartFlushRecvBuf(); } 

} 软件CRC解析 unsigned short crc16(unsigned char *src, unsigned long sizes) {

unsigned char *ptr = NULL; unsigned short i, j, n, ccitt; unsigned short c = 0; unsigned short tabccitt[256]; unsigned short crc = 0; unsigned short tmp = 0; unsigned short sc = 0; for (i = 0; i < 256; i++) { ccitt = 0; c = i << 8; for (j = 0; j < 8; j++) { if ( (ccitt ^ c) & 0x8000 ){ ccitt = ( ccitt << 1 ) ^ 0x1021; } else{ ccitt = ccitt << 1; } c = c << 1; } tabccitt[i] = ccitt; } ptr = src; crc = 0xFFFF; if (ptr != NULL) for (n = 0; n < sizes; n++) { sc = 0X00FF & (unsigned short) *ptr; tmp = (crc >> 8) ^ sc; crc = (crc << 8) ^ tabccitt[tmp]; ptr++; } return crc; 

} 定时发送心跳连接函数 void SendPulse(void)
{

讯享网u8 buf[16]; u16 i, crc; for(i = 0; i <= 13; i++) { if(i<=3) buf[i]=PLSMSG[i]; else if(i<=9) buf[i]=MID[i-4]; else buf[i]=RESMSG[i-10]; } crc = crc16(buf,14); buf[14] = crc>>8; buf[15] = (crc&0x00ff); Send_Data_Uart3((char *)buf,16); 

}
`
主函数While循环的操作

`while(1) { Decode_Packet(); if(TimerCmdFlag>=PULSE_TIME) { TimerCmdFlag = 0; Send_Pulse(); LED0 = !LED0; } }` 

五、实验效果