NRF24L01基本特性：
1.2Mbit/s速率下接收时的峰值电流12.5mA
2.在2Mbit/s速率下@0dBm输出时的峰值电流11mA
3.掉电模式下的功耗400nA
4.待机模式下的功耗32uA
5.130us 的快速切换和唤醒时间
6.具有片内稳压器oltage regulators
7.可在1.9 to 3.6V低电压工作
8. MultiCeiverMT硬件提供同时6个接收机的功能,2Mbit/s 使得高质量的VoIP 成为可能
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 {
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 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 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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