【无线芯片解读】2.4G专题：Si24R1

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简介

应用范围

无线遥控，无线鼠标，无线键盘，无线电子标签，遥控无人机，遥控玩具等。

芯片引脚定义

工作模式：

SI24R1芯片供电电压至少大于1.9V,典型值3.3V，需延时100ms让芯片稳定工作。
关断模式：CONFIG寄存器的PWR_UP位清0，该模式下所有寄存器值与FIFO值保持不变，功耗<0.7uA。也可以通过SPI实现寄存器的读写。芯片的时钟稳定时间一般在1.5~2ms。
待机模式：CE脚拉低，CONFIG寄存器的PWR_UP位置1，该模式下时钟保持工作，功耗<15uA,切换收发时间小于130us。也可以通过SPI实现寄存器的读写。
发射空闲模式：CE脚拉高,CONFIG寄存器的PRIM_RX位清0，不发包（TX FIFO无数据）。也可以通过SPI实现寄存器的读写。
发射模式：CE脚拉高,CONFIG寄存器的PRIM_RX位清0，发包（TX FIFO有数据）。数据发射完成，会产生发射完成中断。
接收模式：CE脚拉高，CONFIG寄存器的PRIM_RX位置1。该模式收包通过数据包的地址和芯片地址比对，CRC检查，然后收到的数据自动存入RX FIFO，并产生数据接收中断。

数据包处理协议

ARQ包格式：

通信模式：

SPI数据与控制接口：

主要寄存器操作：

EN_AA:使能自动确认寄存器

STATUS:状态寄存器

典型芯片电路图：

驱动程序应用：

si24r1.c文件内容：

#include "SI24R1.h" #include "delay.h" u8 TX_ADDRESS[TX_ADR_WIDTH] = { 
   0x0A,0x01,0x07,0x0E,0x01}; /*SPI读写字节函数*/ static u8 SPI_RW(u8 byte) { 
    u8 bit_ctr; for(bit_ctr=0; bit_ctr<8; bit_ctr++) //轮询8位 { 
    if(byte & 0x80) MOSI = 1; //判断如果最高位是高电平，输出高电平 else MOSI = 0; //反之输出低电平  byte = (byte << 1); //左移  SCK = 1; //SCK为高  byte |= MISO; //字节值按位或（相加）  SCK = 0; //SCK为低  } return(byte); //返回字节和  } /*SPI IO初始化函数*/ void SI24R1_Init(void) { 
    SCK = 0; //SCK（SPI）时钟引脚拉低  CSN = 1; //CSN片选引脚拉高  CE = 0; //CE脚拉低，待机准备状态  IRQ = 1; //中断引脚拉高，低电平有效 } /*SPI写寄存器函数*/ u8 SI24R1_Write_Reg(u8 reg, u8 value) { 
    u8 status; CSN = 0; //CSN片选引脚拉低  status = SPI_RW(reg); //返回写的寄存器值  SPI_RW(value);//写值 CSN = 1; //CSN片选引脚拉高 return(status); } /*SPI写数据函数*/ u8 SI24R1_Write_Buf(u8 reg, const u8 *pBuf, u8 bytes) { 
    u8 status,byte_ctr; CSN = 0; //CSN片选引脚拉低  status = SPI_RW(reg);//返回写的寄存器值  for(byte_ctr=0; byte_ctr<bytes; byte_ctr++) //数据遍历写入  SPI_RW(*pBuf++); CSN = 1; //CSN片选引脚拉高  return(status); } /*SPI读寄存器函数*/ u8 SI24R1_Read_Reg(u8 reg) { 
    u8 value; CSN = 0; SPI_RW(reg); value = SPI_RW(0);//读寄存器值  CSN = 1; return(value); } /*SPI读数据函数*/ u8 SI24R1_Read_Buf(u8 reg, u8 *pBuf, u8 bytes) { 
    u8 status,byte_ctr; CSN = 0; status = SPI_RW(reg); for(byte_ctr=0;byte_ctr<bytes;byte_ctr++) pBuf[byte_ctr] = SPI_RW(0); //读数据内容  CSN = 1; return(status); } /*设置接收模式*/ void SI24R1_RX_Mode(void) { 
    CE = 0; SI24R1_Write_Buf(WRITE_REG + RX_ADDR_P0, TX_ADDRESS, TX_ADR_WIDTH); SI24R1_Write_Reg(WRITE_REG + EN_AA, 0x01); SI24R1_Write_Reg(WRITE_REG + EN_RXADDR, 0x01); SI24R1_Write_Reg(WRITE_REG + RF_CH, 40); SI24R1_Write_Reg(WRITE_REG + RX_PW_P0, TX_PLOAD_WIDTH); SI24R1_Write_Reg(WRITE_REG + RF_SETUP, 0x0f); SI24R1_Write_Reg(WRITE_REG + CONFIG, 0x0f); SI24R1_Write_Reg(WRITE_REG + STATUS, 0xff); CE = 1; } /*设置发射模式*/ void SI24R1_TX_Mode(void) { 
    CE = 0; SI24R1_Write_Buf(WRITE_REG + TX_ADDR, TX_ADDRESS, TX_ADR_WIDTH); · SI24R1_Write_Buf(WRITE_REG + RX_ADDR_P0, TX_ADDRESS, TX_ADR_WIDTH); SI24R1_Write_Reg(WRITE_REG + EN_AA, 0x01); SI24R1_Write_Reg(WRITE_REG + EN_RXADDR, 0x01); SI24R1_Write_Reg(WRITE_REG + SETUP_RETR, 0x0a); SI24R1_Write_Reg(WRITE_REG + RF_CH, 40); SI24R1_Write_Reg(WRITE_REG + RF_SETUP, 0x0f); SI24R1_Write_Reg(WRITE_REG + CONFIG, 0x0e); } /*收包函数*/ u8 SI24R1_RxPacket(u8 *rxbuf) { 
    u8 state; state = SI24R1_Read_Reg(STATUS); SI24R1_Write_Reg(WRITE_REG+STATUS,state); if(state & RX_DR) { 
    SI24R1_Read_Buf(RD_RX_PLOAD,rxbuf,TX_PLOAD_WIDTH); SI24R1_Write_Reg(FLUSH_RX,0xff); return 0; } return 1; } /*发包函数*/ u8 SI24R1_TxPacket(u8 *txbuf) { 
    u8 state; CE=0; SI24R1_Write_Buf(WR_TX_PLOAD, txbuf, TX_PLOAD_WIDTH); CE=1; while(IRQ == 1); state = SI24R1_Read_Reg(STATUS); SI24R1_Write_Reg(WRITE_REG+STATUS, state); if(state&MAX_RT) { 
    SI24R1_Write_Reg(FLUSH_TX,0xff); return MAX_RT; } if(state&TX_DS) { 
    return TX_DS; } return 0xFF; } 

si24r1.h头文件内容：

#include "config.h" //SI24R1 PIN DEFINITION #define MOSI P13 // Master Out, Slave In pin (output) #define MISO P10 // Master In, Slave Out pin (input) #define SCK P12 // Serial Clock pin, (output) #define CSN P15 // Slave Select pin, (output to CSN) #define CE P14 // Chip Enable pin signal (output) #define IRQ P11 // Interrupt signal, from nRF24L01 (input) #define TX_ADR_WIDTH 5 // 5×Ö½Ú¿í¶ÈµÄ·¢ËÍ/½ÓÊÕµØÖ· #define TX_PLOAD_WIDTH 32 // Êý¾ÝͨµÀÓÐЧÊý¾Ý¿í¶È //// // SPI(SI24R1) commands #define READ_REG 0x00 // Define read command to register #define WRITE_REG 0x20 // Define write command to register #define RD_RX_PLOAD 0x61 // Define RX payload register address #define WR_TX_PLOAD 0xA0 // Define TX payload register address #define FLUSH_TX 0xE1 // Define flush TX register command #define FLUSH_RX 0xE2 // Define flush RX register command #define REUSE_TX_PL 0xE3 // Define reuse TX payload register command #define NOP 0xFF // Define No Operation, might be used to read status register //// // SPI(SI24R1) registers(addresses) #define CONFIG 0x00 // 'Config' register address #define EN_AA 0x01 // 'Enable Auto Acknowledgment' register address #define EN_RXADDR 0x02 // 'Enabled RX addresses' register address #define SETUP_AW 0x03 // 'Setup address width' register address #define SETUP_RETR 0x04 // 'Setup Auto. Retrans' register address #define RF_CH 0x05 // 'RF channel' register address #define RF_SETUP 0x06 // 'RF setup' register address #define STATUS 0x07 // 'Status' register address #define OBSERVE_TX 0x08 // 'Observe TX' register address #define RSSI 0x09 // 'Received Signal Strength Indecator' register address #define RX_ADDR_P0 0x0A // 'RX address pipe0' register address #define RX_ADDR_P1 0x0B // 'RX address pipe1' register address #define RX_ADDR_P2 0x0C // 'RX address pipe2' register address #define RX_ADDR_P3 0x0D // 'RX address pipe3' register address #define RX_ADDR_P4 0x0E // 'RX address pipe4' register address #define RX_ADDR_P5 0x0F // 'RX address pipe5' register address #define TX_ADDR 0x10 // 'TX address' register address #define RX_PW_P0 0x11 // 'RX payload width, pipe0' register address #define RX_PW_P1 0x12 // 'RX payload width, pipe1' register address #define RX_PW_P2 0x13 // 'RX payload width, pipe2' register address #define RX_PW_P3 0x14 // 'RX payload width, pipe3' register address #define RX_PW_P4 0x15 // 'RX payload width, pipe4' register address #define RX_PW_P5 0x16 // 'RX payload width, pipe5' register address #define FIFO_STATUS 0x17 // 'FIFO Status Register' register address #define DYNPD 0x1C #define FEATURE 0x1D //// // STATUS Register  #define RX_DR 0x40 // #define TX_DS 0x20 #define MAX_RT 0x10 //// // FUNCTION's PROTOTYPES // //// //SI24R1 API Functions void SI24R1_Init(void); //SI24R1 Pin Init u8 SI24R1_Write_Reg(u8 reg, u8 value); u8 SI24R1_Write_Buf(u8 reg, const u8 *pBuf, u8 bytes); u8 SI24R1_Read_Reg(u8 reg); u8 SI24R1_Read_Buf(u8 reg, u8 *pBuf, u8 bytes); void SI24R1_RX_Mode(void); void SI24R1_TX_Mode(void); u8 SI24R1_RxPacket(u8 *rxbuf); u8 SI24R1_TxPacket(u8 *txbuf); #endif 

main.c文件内容：

#include "SI24R1.h" #include "delay.h" #include "string.h" #define LED3 P16 #define LED4 P35 #define KEY1 P12 #define KEY2 P14 unsigned char tx_data[32]={ 
   0}; unsigned char rx_data[32]={ 
   0}; #define FOSC L #define BAUD //9600 #define UART_RX_FIFO 32 unsigned char UART_RX_Data[UART_RX_FIFO]; /*串口函数初始化*/ void uart_init(void) { 
    SCON = 0x50; T2L = (65536 - (FOSC/4/BAUD)); T2H = (65536 - (FOSC/4/BAUD)) >> 8; AUXR = 0x14; AUXR |= 0x01; ES = 1; EA = 1; } /*串口发送字符函数*/ void SendData(unsigned char Data) { 
    SBUF = Data; while(TI == 0); TI = 0; } /*串口发送字符串函数*/ void SendString(char *s) { 
    while(*s) { 
    SendData(*s++); } } /*串口接收字符函数*/ void RecvData(unsigned char Data) { 
    unsigned int i; for(i=0;i<UART_RX_FIFO;i++) { 
    UART_RX_Data[i] = Data; } while(RI == 0); RI = 0; } /*设置串口响应中断*/ void UART_i() interrupt 4 { 
    if(RI) { 
    RI = 0; RecvData(SBUF); } if(TI) { 
    TI = 0; } } void main(void) { 
    unsigned char udata=0，rssi; uart_init(); //串口初始化 SI24R1_Init();//2.4G SPI初始化 #if 0 SI24R1_TX_Mode(); //设置发射模式 #else SI24R1_RX_Mode(); //设置接收模式 #endif while(1) { 
    #if 0 udata = SI24R1_TxPacket(tx_data);//发包 #else udata = SI24R1_RxPacket(rx_data);//收包 rssi=SI24R1_Read_Reg(RSSI); //获取接收信号强度 if(rssi == 0) { 
    SendString("<-60dBm\r\n"); } else { 
    SendString(">-60dBm\r\n"); } #endif delay_ms(50); // Broadcasting interval if(udata == 0xff) { 
    LED4=0;//SendString("send fail\r\n"); LED3=0; SendString("send or recv fail\r\n"); } else { 
    LED4=1;//SendString("send ok\r\n"); LED3=1; SendString("send or recv ok\r\n"); } } } 

认证指南：

随着国家强制对无线产品的认证要求，针对SI24R1这款芯片，一般过的认证频率为：2402MHz 2440MHz 2480MHz。可以通过下面的代码来完成定频中的功率等级、速率、信道频率、单载波及调制模式的设置：

#include "SI24R1.h" #include "delay.h" #define RF_POWER_F12 0x00//-12dBm #define RF_POWER_F6 0x01//-6dBm #define RF_POWER_F4 0x02//-4dBm #define RF_POWER_0 0x03//0dBm #define RF_POWER_1 0x04//1dBm #define RF_POWER_3 0x05//3dBm #define RF_POWER_4 0x06//4dBm #define RF_POWER_7 0x07//7dBm #define RF_FREQ_250K 0x20//250Kbps #define RF_FREQ_1M 0x00//1Mbps,对应带宽1MHz #define RF_FREQ_2M 0x08//2Mbps,对应带宽2MHz #define RF_CH_2525 0x7D//125  #define RF_CH_2500 0x64//100  #define RF_CH_2482 0x52//82  #define RF_CH_2480 0x50//80 2480MHz #define RF_CH_2463 0x3F//63  #define RF_CH_2462 0x3E//62  #define RF_CH_2442 0x2A//42  #define RF_CH_2440 0x28//40 2440MHz #define RF_CH_2402 0x02//02 2402MHz #define RF_CH_2400 0x00//00  #define Single_Carrier_MODE 1 //单载波模式 #define Modulated_Wave_MODE 0 //调制波模式 #define ADV_INTERVAL_MS 50 //广播间隔 

供认证测试设置使用的函数

void Set_CERTIFIED_Mode(unsigned charrf_Ch,unsigned char rf_Power,unsigned char rf_Freq ,unsigned char rf_Mode) { 
    static unsigned char RF_value = 0; CE = 0; SI24R1_Write_Buf(WRITE_REG + TX_ADDR, TX_ADDRESS, TX_ADR_WIDTH); SI24R1_Write_Buf(WRITE_REG + RX_ADDR_P0, TX_ADDRESS, TX_ADR_WIDTH); SI24R1_Write_Reg(WRITE_REG + EN_AA, 0x01); SI24R1_Write_Reg(WRITE_REG + EN_RXADDR,0x01); SI24R1_Write_Reg(WRITE_REG + SETUP_RETR,0x0a); rf_Ch = rf_Ch&0xff; SI24R1_Write_Reg(WRITE_REG + RF_CH,rf_Ch); RF_value |= rf_Power; RF_value |= rf_Freq; switch(rf_Mode) { 
    case Single_Carrier_MODE: RF_value |= 0x80;//cont_wave RF_value |= 0x10;//pll_lock break; case Modulated_Wave_MODE: break; } RF_value = RF_value&0xff; SI24R1_Write_Reg(WRITE_REG + RF_SETUP,RF_value); SI24R1_Write_Reg(WRITE_REG + CONFIG,0x0e); } void send_packet(unsigned int interval_ms,unsigned char *data_value) { 
    SI24R1_TxPacket(data_value); delay_ms(interval_ms); // Broadcasting interval } 

设置认证参数

unsigned char adv_data[32]={ 
   0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,0xF0,0xE0,0xD0,0xC0,0xB0,0xA0,0x90,0x80,0x70,0x60,0x50,0x40,0x30,0x20,0x10,0x00};//数据包 void main(void) { 
    SI24R1_Init(); Set_CERTIFIED_Mode(RF_CH_2402,RF_POWER_0,RF_FREQ_1M,Single_Carrier_MODE);//设置频率、功率、速率、模式 while(1) { 
    send_packet(ADV_INTERVAL_MS,adv_data);//定时发包 } } 

认证常见问题

模拟BLE信号

/* BLE */ #define GAP_ADTYPE_MESH_TYPE_ADVDATA 0x2A #define GAP_ADTYPE_LOCAL_NAME_COMPLETE 0x09 //!< Complete local name #define GAP_ADTYPE_MANUFACTURER_SPECIFIC 0xFF //!< Manufacturer Specific Data: first 2 octets contain the Company Identifier Code followed by the additional manufacturer specific data /*BLE的CRC校验函数，24bit-CRC算法*/ static void LeLfsrCrc(const unsigned char* Data, unsigned char Len, unsigned char* Dst) { 
    unsigned char _v, _t, _d; while(Len--) { 
    _d = *Data++; for(_v = 0; _v < 8; _v++, _d >>= 1) { 
    _t = Dst[0] >> 7; Dst[0] <<= 1; if(Dst[1] & 0x80) Dst[0] |= 1; Dst[1] <<= 1; if(Dst[2] & 0x80) Dst[1] |= 1; Dst[2] <<= 1; if(_t != (_d & 1)) { 
    Dst[2] ^= 0x5B; Dst[1] ^= 0x06; } } } } /*单字节高低位互换函数，大小端*/ static unsigned char Bit_Swap(unsigned char Byte) { 
    unsigned char Value = 0,i; unsigned char Data[8]; for(i=0;i<8;i++) { 
    Data[i] = 0x01<<i; if(Byte & Data[i]) Value |= 0x80>>i; } return Value; } /*BLE LFSR白化实现*/ static void LeLfsrWhite(unsigned char* Data, unsigned char Len, unsigned char Coeff) { 
    unsigned char i; while(Len--) { 
    for(i = 1; i; i <<= 1) { 
    if(Coeff & 0x80) { 
    Coeff ^= 0x11; (*Data) ^= i; } Coeff <<= 1; } Data++; } } /*加密BLE包*/ static void EncodeBlePacket(unsigned char* Packet, unsigned char Len, unsigned char Chan) { 
    unsigned char i, DataLen = Len - 3; LeLfsrCrc(Packet, DataLen, Packet + DataLen); for(i = 0; i < 3; i++, DataLen++) Packet[DataLen] = Bit_Swap(Packet[DataLen]); LeLfsrWhite(Packet, Len, Bit_Swap(Chan)|2); for(i = 0; i < Len; i++) Packet[i] = Bit_Swap(Packet[i]); } /*设置BLE模式*/ void SI24R1_BLE_Mode(void) { 
    CE = 0; SI24R1_Write_Reg(WRITE_REG+CONFIG,0x12);//关闭最大重发计数中断，关闭CRC，开机模式，发射模式 SI24R1_Write_Reg(WRITE_REG+EN_AA,0x00); /* no ack ，不使能自动确认*/ SI24R1_Write_Reg(WRITE_REG+EN_RXADDR,0x00); /* no rx，不使能接收数据管道地址 */ SI24R1_Write_Reg(WRITE_REG+SETUP_AW,0x02); /* 4-byte addr，发射地址宽度4字节 */ SI24R1_Write_Reg(WRITE_REG+SETUP_RETR,0x00); /* no auto-retransmit，关闭自动重发 */ SI24R1_Write_Reg(WRITE_REG+RF_SETUP,0x06); /* 1Mbps at 0dbm */ SI24R1_Write_Reg(WRITE_REG+STATUS,0x3e); /* clear flags，清除标志 */ SI24R1_Write_Reg(WRITE_REG+DYNPD,0x00); /* no dynamic payloads，不使能动态负载长度 */ SI24R1_Write_Reg(WRITE_REG+FEATURE,0x00); /* no features，不使能动态负载*/ SI24R1_Write_Reg(WRITE_REG+RX_PW_P0,32); /* always rx 32 bytes，接收数据管道0数据字节数32字节 */ SI24R1_Write_Reg(WRITE_REG+EN_RXADDR, 0x01); /* rx on pipe 0 ，使能接收数据管道0地址*/ TX_ADDRESS[0] = Bit_Swap(0x8E); TX_ADDRESS[1] = Bit_Swap(0x89); TX_ADDRESS[2] = Bit_Swap(0xBE); TX_ADDRESS[3] = Bit_Swap(0xD6); SI24R1_Write_Buf(WRITE_REG+TX_ADDR,(u8*)TX_ADDRESS, 4);//set wirte address 设置发射方的发射地址 SI24R1_Write_Buf(WRITE_REG+RX_ADDR_P0,(u8*)TX_ADDRESS, 4);//set wirte address 数据管道0的接收地址，发射方需要接收ACK信号，需设一样的地址。 } /*低8位校验和计算*/ static unsigned char check_lockkey(unsigned char *Data,unsigned char Len) { 
    unsigned char result; int i,num = 0; for (i = 0; i < Len; i++) { 
    num = (num + Data[i]) % 256; } result = (char)num; return result; } /*模拟BLE广播包*/ static unsigned char Imitate_Ble_Packet(unsigned char *data_value,unsigned char *data_mac,unsigned char *data_name) { 
    unsigned char Value=0; buf[Value++] = 0x42|0x40; //PDU type, random address; Android:0x42 iPhone:0x40 buf[Value++] = 21; // payload length  buf[Value++] = data_mac[0]; buf[Value++] = data_mac[1]; buf[Value++] = data_mac[2]; buf[Value++] = data_mac[3]; buf[Value++] = data_mac[4]; buf[Value++] = data_mac[5]; #if 0  buf[Value++] = 2; //flags (LE-only, general discoverable mode) buf[Value++] = 0x01; buf[Value++] = check_lockkey(data_value,5);//0x06;//A9;//0x06; buf[Value++] = 4; // length of the name, including type byte buf[Value++] = GAP_ADTYPE_LOCAL_NAME_COMPLETE;//0x09 buf[Value++] = data_name[0];//'A'; buf[Value++] = data_name[1];//'X'; buf[Value++] = data_name[2];//'K'; buf[Value++] = 6; // length of custom data, including type byte buf[Value++] = GAP_ADTYPE_MANUFACTURER_SPECIFIC;//0xFF  buf[Value++] = data_value[0];//0x11; buf[Value++] = data_value[1];//0x22;  buf[Value++] = data_value[2];//0x33;// some test data buf[Value++] = data_value[3];//0x44; buf[Value++] = data_value[4];//0x55;  #else buf[Value++] = 14; //flags (LE-only, general discoverable mode) buf[Value++] = GAP_ADTYPE_MESH_TYPE_ADVDATA; buf[Value++] = check_lockkey(data_mac,6); buf[Value++] = data_mac[0]; buf[Value++] = data_mac[1]; buf[Value++] = data_mac[2]; buf[Value++] = data_mac[3]; buf[Value++] = data_mac[4]; buf[Value++] = data_mac[5]; buf[Value++] = check_lockkey(data_value,6); buf[Value++] = data_value[0];//0x11; buf[Value++] = data_value[1];//0x22;  buf[Value++] = data_value[2];//0x33;// some test data buf[Value++] = data_value[3];//0x44; buf[Value++] = data_value[4];//0x55;  #endif buf[Value++] = 0x55;//55; //CRC start value: 0x buf[Value++] = 0x55;//55; buf[Value++] = 0x55;//55; return Value; } /*BLE发包函数*/ void send_ble_packet(unsigned int interval_ms,unsigned char *data_value,unsigned char *data_mac,unsigned char *data_name) { 
    static unsigned char Len=0; for(ch=0; ch<sizeof(chRf); ch++) { 
    Len = Imitate_Ble_Packet(data_value,data_mac,data_name); SI24R1_Write_Reg(WRITE_REG+RF_CH, chRf[ch]);//hop channel设置信道 SI24R1_Write_Reg(WRITE_REG+STATUS, 0x6E); // clear flags  EncodeBlePacket(buf, Len, chLe[ch]); SI24R1_Write_Reg(FLUSH_TX,0xff); //Clear TX Fifo SI24R1_Write_Reg(FLUSH_RX,0xff); //Clear RX Fifo  SI24R1_TxPacket(buf); delay_ms(2); } delay_ms(interval_ms); // Broadcasting interval }`` 

Si24R1通信异常问题集锦

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