CARRIERs SCAN PROCEDURE With nRF24L01+

[LPO]

Dear Sr.,

Can't detect carrier

They are two PCB one TX Carrier and other mush Detect the carrier
--------------------------------------------------------------------------------------------------------------------------
PCB1 TX CARRIER AT Channel 2.410 Ghz (Without data). This module generate only carrier for detecting for PCB2
PCB1 SW:
5 mS
CE=0
wSPI,#00100000b ;WR CONFIG Register SELECT
wSPI,#00001010b ;EN_CRC bit3 Set=1,PWR_UP bit1 Set=1,Set as PTX bit0=0
5 mS
wSPI,#00100101b ;WR RF_CH Register SELECT
wSPI,#10 ;Channel 2.410Ghz
5 mS
wSPI,#00100110b ;WR RF_SETUP Register SELECT
wSPI,#10001110b ;Continous Carrier Tx, 2Mbis/s, 0dBm Tx
CE=1
HALT
This SW run the carrier is OK
--------------------------------------------------------------------------------------------------------------------------
PCB2 RX CARRIER AT Channel 2.410 Ghz. This module mush detect carrier from PCB
PCB2 SW:
1 munute after PCB1 power on
5 mS
CE=0
wSPI,#00100000b ;WR CONFIG Register SELECT
wSPI,#00001011b ;EN_CRC bit3 Set=1,PWR_UP bit1 Set=1,PRX bit0 Set=1
5 mS
wSPI,#00100101b ;WR RF_CH Register SELECT
wSPI,#10 ;Channel 2.410Ghz
5 mS

CE1:

CE=1
5 mS
CE=0
wSPI,#00001001b ;RD RPD Register SELECT
rSPI,RD STATUS ;RD STATUS
rSPI,RPD ;Lee RPD

All Time Bit0=0 ;For Carrier Detec mush be =1
GOTO CE1
This SW don't detect the carrier
--------------------------------------------------------------------------------------------------------------------------

What I do wrong ?

Thank

[LPO]

Thanks Hakon for your support,
but need understand as this RPD bit is detected as one easy secuence or flowchart mode.
I work in assembler and don't understand well C, but I had found one C secuence than is possible can run, if you can explain it terms as I explain at the top of this Nordic Case Info.

Thanks,
LPO

-----------------------------------------
The source code I found is:
-----------------------------------------
#define CE 9

#define CHANNELS 64 // Define as array to hold channel data
int channel[CHANNELS];

#define _NRF24_CONFIG 0x00 // Registers 0x00
#define _NRF24_EN_AA 0x01 // Registers 0x01
#define _NRF24_RF_CH 0x05 // Registers 0x05
#define _NRF24_RF_SETUP 0x06 // Registers 0x06
#define _NRF24_RPD 0x09 // Registers 0x09

// Get the value of the NRF25L01 Registers
byte getRegister(byte r)
{
byte c;
PORTB &=~_BV(2);
c = SPI.transfer(r&0x1F);
c = SPI.transfer(0);
PORTB |= _BV(2);

return(c);
}

// set the value of a nRF24L01p register
void setRegister(byte r, byte v)
{
PORTB &=~_BV(2);
SPI.transfer((r&0x1F)|0x20);
SPI.transfer(v);
PORTB |= _BV(2);
}


void powerUp(void) // power up the nRF24L01p chip
{
setRegister(_NRF24_CONFIG,getRegister(_NRF24_CONFIG)|0x02);
delayMicroseconds(130);
}

// switch nRF24L01p off
void powerDown(void)
{
setRegister(_NRF24_CONFIG,getRegister(_NRF24_CONFIG)&~0x02);
}

void enable(void) //Activate RX
{
PORTB |= _BV(1);
}

void disable(void) //Deactivate RX
{
PORTB &=~_BV(1);
}

// setup RX-Mode of nRF24L01p
void setRX(void)
{
setRegister(_NRF24_CONFIG,getRegister(_NRF24_CONFIG)|0x01);
enable();

// this is slightly shorter than
// the recommended delay of 130 usec

delayMicroseconds(100);
}

//SCANNING ALL CHANNELS IN 2.4GHz Band

void scanChannels(void)
{
disable();
for( int j=0 ; j<200 ; j++)
{
for( int i=0 ; i<CHANNELS ; i++)
{
// select a new channel
setRegister(_NRF24_RF_CH,(128*i)/CHANNELS);

// switch on RX
setRX();

// wait enough for RX-things to settle
delayMicroseconds(40);

// this is actually the point where the RPD-flag
// is set, when CE goes low
disable();

// read out RPD flag; set to 1 if
// received power > -64dBm
if( getRegister(_NRF24_RPD)>0 ) channel[i]++;
}
}
}

[Håkon Alseth]

Hi,

 

Thanks for the example code.

You need to wait atleast 130 us (Ramp-up time) before reading the RPD bit, and I would also recommend reading this prior to disabling the RX. Could you try this and see if you get the expected result?

Best regards,

Håkon