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

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

ovrebekk — Wed, 04 Nov 2020 09:03:13 GMT

The only way to change the bandwidth is to use a different on-air bitrate.

In general the lower the bitrate the lower the bandwidth.

Which bitrate mode are you using?

Best regards
Torbjørn

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

wzszzxj — Wed, 04 Nov 2020 01:54:34 GMT

HI,Ovrebekk:

I just want know is there any fuctions in the SDK to narrow the bandwidth in a channel?

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

ovrebekk — Tue, 03 Nov 2020 20:28:46 GMT

What does it look like if you show a larger part of the band?

I will discuss this tomorrow with one of my more hardware knowledgeable colleagues to get some input on the plot.

Best regards
Torbjørn

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

wzszzxj — Mon, 02 Nov 2020 14:40:58 GMT

HI，ovrebekk:

I just use ESB the example to twoway exchanging data. When when i is tranmitting,It seem to transmit on many frequency in on channel,as picture below(in channel 3 ):

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

ovrebekk — Wed, 24 Apr 2019 09:16:44 GMT

Hi Chianglin

The best of luck, hopefully you can find some room for improvement.

The nrf_esb library is not optimized for quickly switching between PTX and PRX mode, so the ideal solution would probably be to implement something from scratch (but this would obviously be a lot more time consuming).

Best regards
Torbjørn

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

chianglin — Tue, 23 Apr 2019 13:22:08 GMT

Hi Torbjørn,

I am very glad to hear that you have a very fast holiday. After using the Source Code provided by you, the speed of mutual transmission between the two devices is still not improved (up to 200 packets/sec). I am trying to improve its speed.

Best Regards,

Chianglin

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

ovrebekk — Tue, 23 Apr 2019 08:55:29 GMT

Hi Chianglin

Thank you for the good wishes, it was a great holiday 🙂

I hope you had some progress in the mean time. I am now back in office if you have more questions.

Best regards
Torbjørn

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

chianglin — Fri, 12 Apr 2019 14:20:07 GMT

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

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

ovrebekk — Fri, 12 Apr 2019 12:05:46 GMT

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

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

ovrebekk — Thu, 11 Apr 2019 14:02:50 GMT

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

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

chianglin — Wed, 10 Apr 2019 05:04:17 GMT

Hi Torbjørn,

Do you have any comment about this issue?

Thank you,

Chianglin

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

chianglin — Fri, 05 Apr 2019 15:03:26 GMT

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

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

ovrebekk — Fri, 05 Apr 2019 14:25:43 GMT

Hi Chianglin

Possibly the problem is that you are using auto ACK while at the same time manually switching between PTX and PRX modes.

When using ACK you shouldn't have to switch back and forth PTX and PRX, you can just use the ACK payload feature to send data from the PRX to the PTX if you want to.

If for some reason you want to implement your own ACK scheme, and switch the radios between PTX and PRX, then it doesn't make sense to enable ACK's in the protocol.

I would recommend either disabling ACK's on all your packets, or avoid switching between PTX and PRX modes by using the ACK payload feature.

Best regards
Torbjørn

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

chianglin — Wed, 03 Apr 2019 13:33:37 GMT

Hi Torbjørn,

Thank you for your support.

Sorry, I don't have scope now, so I don't know the status of radio.

Please find the attach file for my full porject.

devzone.nordicsemi.com/.../004.7z

Thank you again.

Chianglin

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

ovrebekk — Wed, 03 Apr 2019 08:17:46 GMT

Hi Chianglin

How did you implement the EebTxRxSwitch(..) function?

If you are able to zip and share your projects with me it should be easier, then I can run the code on my end and see if I can reproduce the problem.

Also, do you have a scope available so that you can analyze the ESB debug lines?
By doing that you should be able to see when the radio of the node and host go into the different modes, which should show you where the delays are occurring.

Best regards
Torbjørn

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

chianglin — Tue, 02 Apr 2019 11:42:10 GMT

Hi Torbjørn,

Actually, the ack function had been disable in my case.

Please reference the attach file, there have two dependent project which need to download to two different device (name: Host and Node).

devzone.nordicsemi.com/.../Host.c

devzone.nordicsemi.com/.../Node.c

The process procedure is:

1. Press a button on Host, host will send a packet (use PacketSend() to send packet in Host.c)

2. Node will receive this packet (in line-88 of Node.c)

3. Node delay 2 ms (use nrf_delay_ms(2)), modify the packet content and send again (line-119 of Node.c)

4. Host will recerive the packet (in line-65 of Host.c)

5. Host delay 2 ms (use nrf_delay_ms(2)), modify the packet content and send again (line-117 of Host.c)

6. Loop step 2 to 5

If I reduce the delay in step 2 and 5 to 1ms, There will cause many TX-Error in these two node

Would you please tell me how to modify this code, then I can speed-up the Packet transmit and receive?

Thank you,

Chianglin

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

ovrebekk — Tue, 02 Apr 2019 10:52:20 GMT

Hi Chianglin

In principle it should take less than 200us to switch from PTX to PRX or vice versa.

The question is whether or not you are able to switch in sync. If the PTX has switched before the PRX then the packet you send will not be successfully received.

Are you using ACK's or retransmits?

If you are using the retransmit feature then any lost packet should be automatically retransmitted, so that you don't see it as a packet loss.

Best regards
Torbjørn