RF link with nRF24L01+ receiver not responding

[Kurtlin]

Register setup on both modules:

Register    data
   0x00        0x38
   0x01        0x00
   0x02        0x01
   0x03        0x03
   0x04        0x00
   0x05        0x4C
   0x06        0x0E 

  0x0A        0x00, 0x00, 0x00, 0x00, 0x05
  0x10        0x00, 0x00, 0x00, 0x00, 0x05

  0x11        0x03

  0xE1
  0xE2
  
  0x00      0x3A

receiver:                                                 transmitter:

 0x00     0x3B                                         loop ~ 1sec       write 0xA0, Byte1, Byte2

wait for INT, read 0x17

the receiver does not receive the bytes, I checked with a spectrum analyzer, the transmitter puts out the RF.

what did I miss on the setup?

thanks for your help

best regards

Kurt

[Ressa]

Hi,

 I just looked into available materials for nRF24L01+ and the settings seems to be ok. Just wondering how is the status of CE pin during the operation? Also you don't receive any signal on IRQ pin either? 
Could you please share schematic of the design mainly the section relevant to nRF24L01+ ? 

[Kurtlin]

Hi,

CE pin is pulled H after flush RX/TX and setting register 0x00->0x3A (checked with multimeter)

I also read the register content back out, it's the same!

here is the circuit

IRQ is input with pull up resistor, stays always H

Best regards

Kurt

[Kurtlin]

Hi Ressa,

  I checked the code again; sorry I made a mistake when I wrote the register setup in my first message. it's definitely 2, I checked by reading back.

I don't have a circuit with antenna connection, I use a module with 8pins and a PCB antenna.

modules are only max 0.5m - 1.0 m apart.

Best regards

Kurt 

[Ressa]

Hi Kurt,

Did you try with 1 Mbps rate as well ? Did it make any difference ? Also please try to clear IRQ flag at least on RX side , right after flushing the TX/TX settings: 


Also there should be some delays in applying the settings. After power up (0x00 - 0x3A/0x3B ), it needs 1.5 ms before radio is ready. So after power up make sure to add this delay . Also after setting CE high, on RX side, it start receiving packets after 130 us. Make sure the TX and RX are following these timing.


nRF24L01P_PS_v1.0.pdf  


There is an old page that contains all SW/HW files with few SW samples for nRF24L01+ in below link:
nRF24 Series - Nordic Semiconductor - nordicsemi.com

 
Also please have a look at below ticket which might be similar problem here. Not emptying RX FIFO might be the issue as it prevents receiving new packets:

Nordic DevZone


Let me know if none of the suggestions solve the issue.

Best regards,
Ressa

[Kurtlin]

Hi Ressa,

 I changed the RF setup (Reg 0x06) to 0x26 (256kBs)

after the 2 flush commands 

I sent Reg 0x07 -> 0x70

then reg 0x00 ->3A

On the transceiver I send then the 2 bytes every 1sec

   CE->L
   reg 0x00 -> 3A
   Flush TX
   Write 0xA0, Byte 1, Byte 2
   CE->H
    15us wait
   CE->L
   reg 0x00 -> 3B
   CE->H 

on the receiver

reg 0x00 ->3B
CE->H

loop   INT = L ?

still no response!!??

best regards

Kurt

[Ressa]

Hi Kurt,

Could you please check below ticket as it describes minimal settings for bidirectional operation:
(+) Problem with nrf24l01 ACK Comunication, can't make it to work - Nordic Q&A - Nordic DevZone - Nordic DevZone

By checking that , just wondering if the 2ms delay is applied after powering up the RX/TX and before setting CE high ?  

Best regards,
Ressa

[Kurtlin]

Hi Ressa,

I copied the code from:

"

Problem with nrf24l01 ACK Comunication, can't make it to work"

and it worked. I have not worked out why, but I think it has to do with the 

RX_PW_PX registers and the EN_RXADDR registers.

Anyway, it works now, thanks very much for your help

Best regards

Kurt