When can change to RX mode while a packet sent out?

[pengyong]

When a packet sent out and get the TX_DS IRQ by nRF24l01+, the mode change to RX and read STATUS register then write the value to the STATUS register and write FLUSH_RX 0xff to get the RX IRQ for data receiving.But looks it affect the packet sending. So I want to know when can change to RX mode while a packet sent out? I would like to send 4 packets and receive 2 packets as quickly as possible continuously. Thanks.

[Hung Bui]

Hi Pengyong,

It's not very clear what your application does. Please give more information on:

• Which chip you are using ?

• Which protocol you are using ? ESB or use the radio directly ?

• You are talking about PTX or PRX ?

• "So I want to know when can change to RX mode while a packet sent out?" You mean you want to switch to RX even before TX finish ?

In this figure, what exactly you want to change ?

[pengyong]

Hi Hung Bui, nRF24l01+ was used with NO auto ACK to get higher throughput. In my application, the nrf24l01+ will sent 4 packets and then receive 2 packet. My question is how to get higher performance from PTX to PRX or PRX to PTX. Thanks.

[Hung Bui]

Hi pengyong,

To switch from TX to RX, you can wait for TX_DS and then change mode, the minimum time to switch is 130us (PLL settling delay). Have you measured your implementation and find how long it would take ?

[pengyong]

Hi Hung Bui,

My understanding from the Product Specification was same to your mention.In fact according to the testing , switching from TX to RX when the TX_DS received, the receiver can not get the packet correctly.400-500us need after the TX_DS received to switching TX to RX. I am not sure what is wrong. Thanks.

Peng Yong

[Hung Bui]

Do you have the receiver running in RX all the time ? Or it's also a TX+RX device ?

Can you provide a small example showing the issue that I can test here ?