NRF24l01 产品性能: 1) 2.4GHZ全球开放ISM频段免许可使用 2) 最高工作速率1Mbps,GFSK高效调制 3) 125个频道满足多点通讯和跳频通讯需求 4) 1.9-3.6V工作,低功耗,待机模式仅1uA. 5) 双通道数据接收,内置环行天线,体积仅17*34mm,通信距离在100m之内,软件编简单。 7) 内置硬件8/16位CRC校验,收发中断标志,每次可发28字节 备注:1。免费提供开发源代码 2。提供廉价开发套件 3。提供全面技术支持和即使方案 4。任何单片机都可实现对NRF系列模块的数据收发控制,
#define uchar unsigned char #define TX_ADR_WIDTH 5 // 5 bytes TX(RX) address width #define TX_PLOAD_WIDTH 20 // 20 bytes TX payload
uchar const TX_ADDRESS[TX_ADR_WIDTH] = {0x34,0x43,0x10,0x10,0x01}; // Define a static TX address
uchar rx_buf[TX_PLOAD_WIDTH]; //接收缓冲区 uchar tx_buf[TX_PLOAD_WIDTH]; //发送缓冲区
uchar flag; /**************************************************/
//管脚定义 sbit CE = P1^0; sbit CSN= P1^1; sbit SCK= P1^2; sbit MOSI= P1^3; sbit MISO= P1^4; sbit IRQ = P1^5; /**************************************************/ uchar bdata sta; sbit RX_DR =sta^6; sbit TX_DS =sta^5; sbit MAX_RT =sta^4; /**************************************************/
/************************************************** Function: init_io(); Description: flash led one time,chip enable(ready to TX or RX Mode), Spi disable,Spi clock line init high /**************************************************/ #define KEY 0xaa void init_io(void) { P0=KEY; // led light CE=0; // chip enable CSN=1; // Spi disable SCK=0; // Spi clock line init high P0=0xff; // led close } /**************************************************/
/************************************************** Function: Inituart();
Description: set uart working mode /**************************************************/ void Inituart(void) { TMOD = 0x20; //timer1 working mode 1 TL1 = 0xfd; //f7=9600 for 16mhz Fosc,and ... TH1 = 0xfd; //...fd=19200 for 11.0592mhz Fosc SCON = 0xd8; //uart mode 3,ren==1 PCON = 0x80; //smod=0 TR1 = 1; //start timer1 } /**************************************************/
/************************************************** Function: init_int0();
Description: enable int0 interrupt; /**************************************************/ void init_int0(void) { EA=1; EX0=1; // Enable int0 interrupt. } /**************************************************/
/************************************************** Function: delay100();
Description: delay 100ms /************************************************** void delay(uchar ) { uchar x; uchar y; for(x=0;x<100;x++) { for(y=0;y<100;y++) _nop_(); } }
/**************************************************/ void delay_ms(unsigned int x) { unsigned int i,j; i=0; for(i=0;i<x;i++) { j=108; ; while(j--); } } /**************************************************/
/************************************************** Function: SPI_RW();
Description: Writes one byte to nRF24L01, and return the byte read from nRF24L01 during write, according to SPI protocol /**************************************************/ uchar SPI_RW(uchar byte) { uchar bit_ctr; for(bit_ctr=0;bit_ctr<8;bit_ctr++) // output 8-bit { MOSI = (byte & 0x80); // output 'byte', MSB to MOSI byte = (byte << 1); // shift next bit into MSB.. SCK = 1; // Set SCK high.. byte |= MISO; // capture current MISO bit SCK = 0; // ..then set SCK low again } return(byte); // return read byte } /**************************************************/
/************************************************** Function: SPI_RW_Reg();
Description: Writes value 'value' to register 'reg' /**************************************************/ uchar SPI_RW_Reg(BYTE reg, BYTE value) { uchar status;
CSN = 0; // CSN low, init SPI transaction status = SPI_RW(reg); // select register SPI_RW(value); // ..and write value to it.. CSN = 1; // CSN high again
return(status); // return nRF24L01 status byte } /**************************************************/
/************************************************** Function: SPI_Read();
Description: Read one byte from nRF24L01 register, 'reg' /**************************************************/ BYTE SPI_Read(BYTE reg) { BYTE reg_val;
CSN = 0; // CSN low, initialize SPI communication... SPI_RW(reg); // Select register to read from.. reg_val = SPI_RW(0); // ..then read registervalue CSN = 1; // CSN high, terminate SPI communication
return(reg_val); // return register value } /**************************************************/
/************************************************** Function: SPI_Read_Buf();
Description: Reads 'bytes' #of bytes from register 'reg' Typically used to read RX payload, Rx/Tx address /**************************************************/ uchar SPI_Read_Buf(BYTE reg, BYTE *pBuf, BYTE bytes) { uchar status,byte_ctr;
CSN = 0; // Set CSN low, init SPI tranaction status = SPI_RW(reg); // Select register to write to and read status byte
for(byte_ctr=0;byte_ctr<bytes;byte_ctr++) pBuf[byte_ctr] = SPI_RW(0); // Perform SPI_RW to read byte from nRF24L01
CSN = 1; // Set CSN high again
return(status); // return nRF24L01 status byte } /**************************************************/
/************************************************** Function: SPI_Write_Buf();
Description: Writes contents of buffer '*pBuf' to nRF24L01 Typically used to write TX payload, Rx/Tx address /**************************************************/ uchar SPI_Write_Buf(BYTE reg, BYTE *pBuf, BYTE bytes) { uchar status,byte_ctr;
CSN = 0; // Set CSN low, init SPI tranaction status = SPI_RW(reg); // Select register to write to and read status byte for(byte_ctr=0; byte_ctr<bytes; byte_ctr++) // then write all byte in buffer(*pBuf) SPI_RW(*pBuf++); CSN = 1; // Set CSN high again return(status); // return nRF24L01 status byte } /**************************************************/
/************************************************** Function: RX_Mode();
Description: This function initializes one nRF24L01 device to RX Mode, set RX address, writes RX payload width, select RF channel, datarate & LNA HCURR. After init, CE is toggled high, which means that this device is now ready to receive a datapacket. /**************************************************/ void RX_Mode(void) { CE=0; SPI_Write_Buf(WRITE_REG + RX_ADDR_P0, TX_ADDRESS, TX_ADR_WIDTH); // Use the same address on the RX device as the TX device
SPI_RW_Reg(WRITE_REG + EN_AA, 0x01); // Enable Auto.Ack:Pipe0 SPI_RW_Reg(WRITE_REG + EN_RXADDR, 0x01); // Enable Pipe0 SPI_RW_Reg(WRITE_REG + RF_CH, 40); // Select RF channel 40 SPI_RW_Reg(WRITE_REG + RX_PW_P0, TX_PLOAD_WIDTH); // Select same RX payload width as TX Payload width SPI_RW_Reg(WRITE_REG + RF_SETUP, 0x07); // TX_PWR:0dBm, Datarate:2Mbps, LNA:HCURR SPI_RW_Reg(WRITE_REG + CONFIG, 0x0f); // Set PWR_UP bit, enable CRC(2 bytes) & Prim:RX. RX_DR enabled..
CE = 1; // Set CE pin high to enable RX device
// This device is now ready to receive one packet of 16 bytes payload from a TX device sending to address // '3443101001', with auto acknowledgment, retransmit count of 10, RF channel 40 and datarate = 2Mbps.
} /**************************************************/
/************************************************** Function: TX_Mode();
Description: This function initializes one nRF24L01 device to TX mode, set TX address, set RX address for auto.ack, fill TX payload, select RF channel, datarate & TX pwr. PWR_UP is set, CRC(2 bytes) is enabled, & PRIM:TX.
ToDo: One high pulse(>10us) on CE will now send this packet and expext an acknowledgment from the RX device. /**************************************************/ void TX_Mode(void) { CE=0; SPI_Write_Buf(WRITE_REG + TX_ADDR, TX_ADDRESS, TX_ADR_WIDTH); // Writes TX_Address to nRF24L01 SPI_Write_Buf(WRITE_REG + RX_ADDR_P0, TX_ADDRESS, TX_ADR_WIDTH); // RX_Addr0 same as TX_Adr for Auto.Ack SPI_Write_Buf(WR_TX_PLOAD, tx_buf, TX_PLOAD_WIDTH); // Writes data to TX payload
SPI_RW_Reg(WRITE_REG + EN_AA, 0x01); // Enable Auto.Ack:Pipe0 SPI_RW_Reg(WRITE_REG + EN_RXADDR, 0x01); // Enable Pipe0 SPI_RW_Reg(WRITE_REG + SETUP_RETR, 0x1a); // 500us + 86us, 10 retrans... SPI_RW_Reg(WRITE_REG + RF_CH, 40); // Select RF channel 40 SPI_RW_Reg(WRITE_REG + RF_SETUP, 0x07); // TX_PWR:0dBm, Datarate:2Mbps, LNA:HCURR SPI_RW_Reg(WRITE_REG + CONFIG, 0x0e); // Set PWR_UP bit, enable CRC(2 bytes) & Prim:TX. MAX_RT & TX_DS enabled.. CE=1;
} /**************************************************/
/************************************************** Function: check_ACK();
Description: check if have "Data sent TX FIFO interrupt",if TX_DS=1, all led light and after delay 100ms all led close /************************************************** void check_ACK() { uchar test; test=SPI_Read(READ_REG+STATUS); // read register STATUS's test=test&0x20; // check if have Data sent TX FIFO interrupt (TX_DS=1) if(test==0x20) // TX_DS =1 { P0=0x00; // turn on all led delay100(); // delay 100ms P0=0xff; } } /**************************************************/
/************************************************** Function: TxData();
Description: write data x to SBUF /**************************************************/ void TxData (uchar x) { SBUF=x; // write data x to SBUF while(TI==0); TI=0; } /**************************************************/
/************************************************** Function: CheckButtons();
Description: check buttons ,if have press,read the key values, turn on led and transmit it; after transmition, if received ACK, clear TX_DS interrupt and enter RX Mode; turn off the led /**************************************************/ void CheckButtons() { uchar Temp,xx,Tempi;
P0=0xff; Temp=P0&KEY; //read key value from port P0 if (Temp!=KEY) { delay_ms(10); Temp=P0&KEY; // read key value from port P0 if (Temp!=KEY) { xx=Temp; Tempi=Temp>>1; // Left shift 4 bits P0=Tempi; // Turn On the led tx_buf[0]=Tempi; // Save to tx_buf[0] TX_Mode(); // set TX Mode and transmitting TxData(xx); // send data to uart //check_ACK(); // if have acknowledgment from RX device,turn on all led SPI_RW_Reg(WRITE_REG+STATUS,SPI_Read(READ_REG+STATUS)); // clear interrupt flag(TX_DS) delay_ms(500); P0=0xff; // Turn off the led RX_Mode(); // set receive mode
while((P0&KEY)!=KEY); } } } /**************************************************/
/************************************************** Function: main();
Description: control all subprogrammes; /**************************************************/ void main(void) { uchar xx; init_io(); // Initialize IO port Inituart(); // initialize 232 uart //init_int0(); // enable int0 interrupt RX_Mode(); // set RX mode while(1) { CheckButtons(); // scan key value and transmit sta=SPI_Read(STATUS); // read register STATUS's value if(RX_DR) // if receive data ready (RX_DR) interrupt { SPI_Read_Buf(RD_RX_PLOAD,rx_buf,TX_PLOAD_WIDTH);// read receive payload from RX_FIFO buffer flag=1; } if(MAX_RT) { SPI_RW_Reg(FLUSH_TX,0); } SPI_RW_Reg(WRITE_REG+STATUS,sta);// clear RX_DR or TX_DS or MAX_RT interrupt flag if(flag) // finish received { flag=0; // set flag=0 P0=rx_buf[0]; // turn on led delay_ms(500); P0=0xff; // turn off led xx=rx_buf[0]>>1;// right shift 4 bits TxData(xx); // send data to uart } } } /**************************************************/
/************************************************** Function: ISR_int0() interrupt 0;
Description: if RX_DR=1 or TX_DS or MAX_RT=1,enter this subprogram; if RX_DR=1,read the payload from RX_FIFO and set flag; /**************************************************/ void ISR_int0(void) interrupt 0 { sta=SPI_Read(STATUS); // read register STATUS's value if(RX_DR) // if receive data ready (RX_DR) interrupt { SPI_Read_Buf(RD_RX_PLOAD,rx_buf,TX_PLOAD_WIDTH);// read receive payload from RX_FIFO buffer flag=1; } if(MAX_RT) { SPI_RW_Reg(FLUSH_TX,0); } SPI_RW_Reg(WRITE_REG+STATUS,sta);// clear RX_DR or TX_DS or MAX_RT interrupt flag } /**************************************************/
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