How to speed up the change between PTX and PRX of esb?

[chianglin]

Hi,

I am using 2 esb devices to test my packet send and received.

My use case is:

1. Node-1 and Node-2 is power-in in PRX mode

2. Node-1 switch to PTX and send a packet, then switch to PRX,

3. Node-2 receive packet, switch to PTX mode and send a packet out. After send packet, switch to PRX.

4. Node-1 receive packet, switch to PTX mode and send a packet out. After send packet, switch to PRX.

....

If the speed between PTX and PRX is to fast, then it will cause many "Send error".  If I add some delay (Ex: use nrf_delay_ms(2)), then there will no error occur.

What is the bottleneck? PTX switch to PRX? or PRX switch to PTX?

Thank you,

Chianglin

[chianglin]

Hi Torbjørn,

You are right, I don't want to use ACK function when ESB transfer/receive all of the time.

I found there have a code which set the "noack" to faulse in line-144 of Node.c, It is my mistake.  But function "esb_send_packet_timer_callback()" will not execute, because timer "m_esb_tx_timer_id" doesn't enable.

How to modify my program to speed-up the switch between PTX and PRX, If I want to disable ACK in ESB function?

Thank you

Chianglin

[chianglin]

Hi Torbjørn,

Do you have any comment about this issue?

Thank you,

Chianglin

[ovrebekk]

Hi Chianglin

Sorry for the late reply, I have been busy with travel and other things. 

I will do a small test tomorrow and try to benchmark the TX/RX turnaround time. Once I know how fast it should be I can compare it to your results, and send you my test code. 

Best regards
Torbjørn

[ovrebekk]

Hi Chianglin

I performed some testing based on this example. 

The example is set up to do something similar to your application. It stays in RX mode most of the time, but switches briefly to TX mode when you want to send a packet, and then switches back to RX again. 

Based on the settings used in the example I measured the total turnaround from switching to TX mode, sending a packet, and switching back to RX mode, to take about 250us, plus the time needed to enable the radio in RX mode, which is 130us by default. So the total switch should happen in about 380us. 

If you change the parameters of test, such as the RF bitrate and the packet length, then this will change obviously. You can download the example and give it a try if you like. 

The next week I will be out in Easter vacation unfortunately, and won't be able to respond, but I will be back in the office on the 23rd of April. 

Best regards
Torbjørn

[chianglin]

HI Torbjørn,

Thank you for your serious support.

I will study your sample code and try to improve my TX/RX performance.

I wish you a happy holiday.

Best Regards,

Chianglin