FSK uplinks arrive in gateway logs, MQTT, not arriving in console

ChirpStack Gateway OS
1

Hi folks,

I am working with FSK modulation and it looks like my device is successfully using FSK modulation on the 868.8MHz channel on EU868. Uplinks on all LoRa datarates arrive nicely on the gateway, sent through MQTT, to the gateway console and in the device console. However, as soon as an FSK uplink is sent by my device, while it is being picked up by the gateway and forwarded through MQTT, it does not arrive on the gateway console nor on the device console.

An excerpt of system/gateway log:

Sat Aug 17 11:57:27 2024 user.info chirpstack-mqtt-forwarder[8792]: Received gateway stats
Sat Aug 17 11:57:27 2024 user.info chirpstack-mqtt-forwarder[8792]: Sending gateway stats event, topic: eu868/gateway/ce77157009a7eba4/event/stats
Sat Aug 17 11:57:31 2024 user.info chirpstack-concentratord-sx1301[9056]: Frame received, uplink_id: 2610325176, count_us: 1806749370, freq: 868300000, bw: 250000, mod: LoRa, dr: SF7
Sat Aug 17 11:57:31 2024 user.info chirpstack-mqtt-forwarder[8792]: Received uplink frame, uplink_id: 2610325176
Sat Aug 17 11:57:31 2024 user.info chirpstack-mqtt-forwarder[8792]: Sending uplink event, uplink_id: 2610325176, topic: eu868/gateway/ce77157009a7eba4/event/up
Sat Aug 17 11:57:37 2024 user.info chirpstack-concentratord-sx1301[9056]: Frame received, uplink_id: 206270531, count_us: 1812774306, freq: 868800000, bw: 125000, mod: FSK, dr: FSK(50000)
Sat Aug 17 11:57:37 2024 user.info chirpstack-mqtt-forwarder[8792]: Received uplink frame, uplink_id: 206270531
Sat Aug 17 11:57:37 2024 user.info chirpstack-mqtt-forwarder[8792]: Sending uplink event, uplink_id: 206270531, topic: eu868/gateway/ce77157009a7eba4/event/up
Sat Aug 17 11:57:55 2024 daemon.err postmaster[2022]: 2024-08-17 09:57:55.616 UTC [2] LOG:  checkpoint starting: time

Screenshot of gateway console:
image

I know that these two uplinks are only 6 seconds apart, I have it on a push-button, I’ve just retried with half an hour in between uplinks but that doesn’t make a difference.

Is there any form of debugging I can do to find out why these uplinks are dropped? Or any ideas for a solution?

Hardware: Raspberry Pi 3B v1.2 with Pi Supply hat running fresh Chirpstack OS install from this morning (ChirpStack Gateway OS 4.4.0 Full / LuCI openwrt-23.05 branch git-24.135.44542-f1ec9c2).

Note: I am testing the FSK modulation so cannot guarantee it is implemented 100% correctly, but given that the gateway picks it up and forwards it, it appears to me this is not the issue.

2

Can someone help me to debug this issue?

3

Still looking for some more information on this… got back to testing this, now with improved radio drivers. Still only activity in the gateway log, and not in the device console.

Fri Oct 25 23:40:14 2024 user.info chirpstack-concentratord-sx1301[2703]: Frame received, uplink_id: 1674442989, count_us: 1033899774, freq: 868800000, bw: 125000, mod: FSK, dr: FSK(50000)
Fri Oct 25 23:40:14 2024 user.info chirpstack-mqtt-forwarder[2731]: Received uplink frame, uplink_id: 1674442989
Fri Oct 25 23:40:14 2024 user.info chirpstack-mqtt-forwarder[2731]: Sending uplink event, uplink_id: 1674442989, topic: eu868/gateway/ce77157009a7eba4/event/up
Fri Oct 25 23:40:28 2024 user.info chirpstack-concentratord-sx1301[2703]: Frame received, uplink_id: 2717531015, count_us: 1048169106, freq: 868800000, bw: 125000, mod: FSK, dr: FSK(50000)
Fri Oct 25 23:40:28 2024 user.info chirpstack-mqtt-forwarder[2731]: Received uplink frame, uplink_id: 2717531015
Fri Oct 25 23:40:28 2024 user.info chirpstack-mqtt-forwarder[2731]: Sending uplink event, uplink_id: 2717531015, topic: eu868/gateway/ce77157009a7eba4/event/up

Sorry for the ping, but dare I summon @brocaar The Great?
Any debugging steps or insights into the state of FSK within Chirpstack?

4

I would look at the chirpstack logs (above you are sharing the concentratord and mqtt forwarder logs only). Please make sure that the channels are also configured in the region_XXXXX.toml file.

5

Thanks for the reply! :slight_smile:

I’ve modified EU868 to look like this:

image
image674×746 14.1 KB

Where would I find/configure this on the Chirpstack Gateway OS? I can’t find any info besides for Ubuntu/Debian installs.

6

To make things more interesting: I was running on Gateway OS 4.4, and decided to update to 4.5.4 to see if it would help in any way. I changed the EU868.toml back to the screenshot above. But now the system log doesn’t even show the entries for FSK anymore, as if it didn’t receive the uplinks…

So the question is: are there any reports at all that Chirpstack works with FSK?

7

It is not commonly used, but I worked on a FSK use-case in the past for EU868. Let me do some testing and get back to you.

1 Like
8

@brocaar ping as reminder before the topic closes (not sure I have permissions to re-open) :slight_smile:

9

This topic was automatically closed after 90 days. New replies are no longer allowed.

11

This was fixed in Fix incorrect FSK datarate multiplication. · chirpstack/chirpstack-concentratord@1d29728 · GitHub

2 Likes
12

@brocaar thank you for investigating!! I will await the next release or see if I can get it compiled myself to check it out. Fingers crossed :crossed_fingers:

13

I spent a fair few hours today trying to compile the Gateway OS from source, but after a valiant fight, file permissions finally got the better of me during make. So I will wait for the next concentratord/OS release :slight_smile:

14

@brocaar THANKS!

    "txInfo": {
        "frequency": 868800000,
        "modulation": {
            "fsk": {
                "datarate": 50000
            }
        }
    }
15

could you please provide the settings you used in .toml for fsk!

16

Only a few modifications are necessary, so I won’t dump the whole .toml here.

You must edit the max_dr field:

max_dr = 7

And then configure one of the extra_channels - I changed the last one:

    [[regions.network.extra_channels]]
      frequency = 868800000
      min_dr = 7
      max_dr = 7

Be aware that the frequency is fixed at 868.8 for FSK and that frequency only allows DR7.

1 Like
17

ok thats all i needed thanks.

18

Can you please tell me what changes did you do in node?

19

None*, as I used RadioLib on my device which nicely handles FSK on all supported radios.

(*) Except forcing the device to uplink at DR7 as ADR only covers DR0-DR5.

1 Like
20

So i tried sending join requests DR7 But the thing is that i dont see anything in chirpstrack gateway console is the server rejecting it?