nRF24L01无线介绍

51测试程序

实测可用!

#define TX_ADR_WIDTH    5

#define RX_ADR_WIDTH    5

#define TX_PLOAD_WIDTH  32

#define RX_PLOAD_WIDTH  32

#define MAX_TX  	0x10	//达到最大发送次数中断

#define TX_OK   	0x20	//TX发送完成中断

#define RX_OK   	0x40	//接收到数据中断

const uchar TX_ADDRESS[TX_ADR_WIDTH]={0xEE,0xDD,0xCC,0xBB,0xAA};	//发送地址

const uchar RX_ADDRESS[RX_ADR_WIDTH]={0xAA,0xBB,0xCC,0xDD,0xEE};

sbit CE   = P2^7;

sbit CSN  = P2^6;

sbit MISO = P2^3;

sbit MOSI = P2^4;

sbit SCK  = P2^5;

sbit IRQ  = P2^2;

sbit LED=P1^0;

void delay_us(uchar num)

{

	uchar i;

	for(i=0;i>num;i++)

 	_nop_();

}

void delay(uint t)

{

	uchar k;

	while(t--)

	for(k=0;k<200;k++);

}

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

}

uchar SPI_Write_Reg(uchar reg, uchar 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

}

uchar SPI_Write_Buf(uchar reg, uchar *pBuf, uchar bytes)

{

	uchar status,byte_ctr;

	CSN = 0; // Set CSN low, init SPI tranaction

	status = SPI_RW(reg); // Select register to write to

	for(byte_ctr=0; byte_ctr<bytes; byte_ctr++) // then write all

		SPI_RW(*pBuf++);

	CSN = 1; // Set CSN high again

	return(status); // return nRF24L01 status byte

}

void RX_Mode_Init(void)

{

	CE=0;

	SPI_Write_Buf(WRITE_REG + TX_ADDR, TX_ADDRESS, TX_ADR_WIDTH);

	SPI_Write_Buf(WRITE_REG + RX_ADDR_P0, RX_ADDRESS, RX_ADR_WIDTH);

	SPI_Write_Reg(WRITE_REG + EN_AA, 0x01); // Enable Auto.Ack:Pipe0

	SPI_Write_Reg(WRITE_REG + EN_RXADDR, 0x01); // Enable Pipe0

	SPI_Write_Reg(WRITE_REG + RF_CH, 0);

	SPI_Write_Reg(WRITE_REG + RX_PW_P0, TX_PLOAD_WIDTH);

	SPI_Write_Reg(WRITE_REG + RF_SETUP, 0x0f);

	SPI_Write_Reg(WRITE_REG + CONFIG, 0x0f); // Set PWR_UP bit, enable

	CE = 1; // Set CE pin high to enable RX device

}

uchar SPI_Read_Reg(uchar reg)

{

	uchar 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

}

uchar NRF24L01_TxPacket(uchar *txbuf)

{

	uchar state;

	CE=0;

	SPI_Write_Buf(WR_TX_PLOAD,txbuf,TX_PLOAD_WIDTH); //写数据到TX_BUF

 	CE=1;

	while(IRQ==1); //等待发送完成

	LED = ~LED;

	state=SPI_Read_Reg(STATUS);

	SPI_Write_Reg(WRITE_REG+STATUS,state); //清除中断标志TX_DS或MAX_RT

	if(state&MAX_TX) //达到最多重发中断

	{

		SPI_Write_Reg(FLUSH_TX,0xff); //清除TX FIFO寄存器

		return MAX_TX;

	}

	if(state&TX_OK) //发送完成

	{

		return TX_OK;

	}

	return 0xff; //发送失败

}

void Send_Buf(uchar *buf)

{

	CE=0;

	SPI_Write_Reg(WRITE_REG+CONFIG,0x0e);

	CE=1;

	delay_us(15);

	NRF24L01_TxPacket(buf);

	CE=0;

	SPI_Write_Reg(WRITE_REG+CONFIG, 0x0f);

	CE=1;

}

int main()

{

	uchar buf[TX_PLOAD_WIDTH];

	RX_Mode_Init();

	buf[0]=2; //无线串口模块需要第一位标识长度(忽略)

	buf[1]=0xaa;

	buf[2]=0x55;

	while(1)

	{

		Send_Buf(buf);

		delay(1000);

	}

}

模块不能自发自收

TX_ADDR和RX_ADDR_P0地址可以相同。但是TX_ADDR是目标板地址，RX_ADDR_P0是本模块地址。只有收发地址配置正确才能收发成功

最主要是RX_Mode_Init中寄存器的配置：

RF_CH，射频通道频率。收发必须一致（F0= 2400 + RF_CH [MHz]）

RF_SETUP，射频寄存器。数据传输速率、发射功率、低噪声放大增益，收发必须一致

CRCO，校验方式。收发必须一致