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]

Hi,

tested With PLL_LOCK Set (bit4=1) at PTX

the register RPD continue Reset (bit0=0) at PRX. Carrier non detected

Best regards,

LPO

PS: The Transceiver is RF2401PRO of NICERF from China. This claim it adopt Nordic's RF chip nRF24L01+

[LPO]

Hi,

Hakon thanks for your replay...

On Page 25 of 78 of nRF24L01+ Single Chip 2.4GHz Transceiver Product Specification v1.0

6.4 Received Power Detector measurements

Can see "If no packets are received the RPD is latched at the end of a receive period as a result of host MCU setting CE low", option necesary for me search of ocuped channels without modulation (only carriers or others diferents modulations).

In me case they are one bucle  of 5mS between CE=1 and CE=0 on PRX mode

Mush be > Tstby2a +Tdelay_AGC=130us + 40us but very less of 5mS ?

Best regards,

LPO

[Håkon Alseth]

Hi,

 

The RPD bit shall be '1' if there is energy in the current receiving channel is > -64 dBm, it is just that this bit is held for a given period if you are receiving a valid packet.

You shall still be able to use this bit to detect energy from for instance bluetooth or wifi.

Have you checked the current consumption (or the carrier using a spectrum analyzer) of your transmitter to see if it is actually transmitting? It should be 11 to 12 mA.

Same with your receiver, does it show ~14 mA in RX mode?

 

Kind regards,

Håkon

[LPO]

Hi,

" it is just that this bit is held for a given period if you are receiving a valid packet"

With the specification "If no packets are received the RPD is latched at the end of a receive period as a result of host MCU setting CE low or RX time out controlled by Enhanced ShockBurst" , is no need receiving a valid packet i think.

The spectrum analyzer indicate they are carrier, but the RPD Register continue to 00' (STATUS=0E' corect)

I can be rong, but i think the nRF24L01+ can leve send only carrier and detect only carrier, similar to one comunication OOK

Kind regards,

LPO

[Håkon Alseth]

Yes, you are correct. This bit shall detect energy, but then it will not hold the RPD bit high for a longer period (as it would if a address match is found)

Could you try to keep the RX on, and do not duty cycle (in 5 ms pattern), to see if this has any impact on the RPD bit read out?

 

[LPO]

Hi, I tested whit the module MIKROE-1305 whit understand genuine nRF24L01+ I think. And the results are similar.

The energy detect funtion mush be inproved on nRF24L01+ if too only carriers or other chanels of other equipement exist and want be detected. This improviment is important when is need search free chanels on noisy ambients. Meanwile the specification mush corrected at tested cases.

If some people had detected energy with this cip, please talk here.

Thanks,

LPO