Wireless nRF24L01+ sniffer for MySensors

[marceltrapman]

@Yveaux

Oh yeah, I added support for some status leds to the Sniffer, connected to A0..A4 and via resistors to GND:

• A0 sniffer monitoring (LED turns off during reset)
• A1 sniffer receiving a packet
• A2 sniffer transmitting (serially) a packet
• A3 new configuration received
• A4 buffer overflow

Maybe I should create a (little) shield for this that holds the radio as well.
Or just use a prototype board...

[Yveaux]

@marceltrapman Maybe all of the LEDs are a bit overkill, but the RX LED and maybe the buffer-full LED can seriously be handy.

[marceltrapman]

I only checked the UNO with the new sketch (no LEDs) and the new iteration of nrf24snif.exe and both work as expected...

@Yveaux Well done again!

[Yveaux]

@marceltrapman And? How did the testing go?
I fixed the Nrf24sniff.exe to use static linking so the msvcr110.dll should no longer be required.
Also fixed executable so it runs on WinXP now (untested...).

[marceltrapman]

@Yveaux To be honest, I have played with it a little but I have not come much further.
Spent my time this weekend on other things :)
Will let you know soon!

[Rasmus Eneman]

Could the line quality information be queried directly by the gateway so that it can be known without additional hardware?

[Yveaux]

@Rasmus-Eneman no, the nrf24 does not expose it. You can query the amount of retries it took before a message got an acknowledgement, which could be used as quality indication.

[Rasmus Eneman]

@Yveaux Okej, Thank You!

[marceltrapman]

@Yveaux said:

And? How did the testing go?

So, testing went well :)
I found a couple of malformed packets coming in so I will have to investigate that.
Yesterday evening I created my first shield, first double sided board and in fact the first true 'home brew' pcb in my entire life...

This is what it looks like (it is a bit of a mess because I messed up my via's the first time...

[Yveaux]

@marceltrapman Wooow! First 'official' sniffer PCB! :+1: (did you give it an oldskool look? looks 50 years+ old :-)
Great it worked out that well!

In my experience there are always some malformed packets, nothing to worry about.

[Damme]

This post is deleted!

[marceltrapman]

@Yveaux It is a combination of the board color (it really is a bit 'greenish') the green matte, daylight gone and the flash light :)

I am pretty content with it except that I need to think about those via's next time as well as using flux.

Any idea where those malformed packets come from?

[Yveaux]

@marceltrapman try to combine vias with through hole components. E.g a resistor write can bring you to the other side of the board.
Or just make the board single sided. Should be doable for such a board and it is also easier to construct.
I switched to smd primarily to prevent drilling and reduce board space...
Just a matter of taste/laziness :)

[Yveaux]

@marceltrapman said

Any idea where those malformed packets come from?

I guess it's just inherent to wireless traffic. The same reason why a Wi-Fi connection gives different rates all of the time.
It's just a hunch, I didn't really dive into it.
Using the sniffer we could also get some real figures on e.g. the capacitor fix. It all can make a difference but as long as you cannot measure objectively it is all guessing...

[marceltrapman]

@Yveaux said:

try to combine vias with through hole components. E.g a resistor write can bring you to the other side of the board.

I know and I did that with the LED's but with a header that is more difficult.

Or just make the board single sided. Should be doable for such a board and it is also easier to construct.

I am sure but I did not want to do that. This also was a learning project for me :)

I switched to smd primarily to prevent drilling and reduce board space...
Just a matter of taste/laziness :)

I am going to do that as well but I wanted to do one step at a time...

Thanks for your advice, much appreciated!!!

[hek]

Hackaday! Congrats.

http://hackaday.com/2014/08/05/sniffing-nrf24l01-traffic-with-wireshark/

[Yveaux]

@hek wow! Thanks for the tip!
Hope this will also boost mysensors popularity!

Over 1000 hits on my blog in half a day! Wow!

[Yveaux]

Updated the sniffer's Wireshark dissectors to MySensors 1.4b protocol version of Aug 18, 2014.
Please update the **mysensors2.dll **when you update to this 1.4b version.

[Sparkman]

@Yveaux Thanks for putting this together. I'm trying it out today and seem to have everything running properly and without errors, but it's not capturing any packets. Can I just run nrf24sniff with all default parameters (other than the com port) for the current 1.4 release, or do I need to change some of them? I haven't made any changes to the default mysensor settings such as channel and data rate. I'm running it on a Mega, but have tested the radio, etc. using the BinarySwitchSensor sketch and it's communicating properly to my gateway/controller.

Thanks
Al

[Yveaux]

@Sparkman Even if the MySensors protocol changed w.r.t. the version supported by the sniffer you should still be able to capture raw nRF24 packets on air. Only the MySensors dissection could fail in this case.

You should double check the values of DEFAULT_RF_CHANNEL, DEFAULT_RF_DATARATE and DEFAULT_RADIO_ID in NRF24_sniff.ino.
They should match the MySensors configuration from MyConfig.h: RF24_CHANNEL, RF24_DATARATE and BASE_RADIO_ID.
The MySensors default datarate has gone down from 1Mbps to 25Kbps, so I would expect the DEFAULT_RF_DATARATE in the sniffer causes the malfunction.

The SPI/pin settings for the radio connection could also be different on your Mega. The sniffer only supports hardware SPI. Other pins are configured in the same NRF24_sniff.ino:

    #define RF_CE_PIN                      (9)
    #define RF_CS_PIN                      (10)
    #define RF_IRQ_PIN                     (2)
    #define RF_IRQ                         (RF_IRQ_PIN-2) 

Also, the sniffer uses interrupts for quick response to new messages, so make sure the IRQ pin is connected between the Mega and the nRF24 (MySensors doesn't use) !

To rule out any issues caused by the Mega, could you test the sniffer using a regular Uno?

Good luck!