Hi @evb,
thanks a lot for your quick response. You were exactly right: My sensor was still running the "old" RFM69 driver and I was not aware that the new one is not backward-compatible. It is also briefly mentioned in the documentation - link.
For completeness (and other users who may face the same problems):
Second problem which I experienced was that my gateway was disconnecting from my mosquitto mqtt broker after 0-2 minutes. Logfile mosquitto.log was showing:
2021-10-12T13:25:42: mosquitto version 2.0.12 running
2021-10-12T13:28:32: New connection from 192.168.17.4:55389 on port 1883.
2021-10-12T13:28:32: New client connected from 192.168.17.4:55389 as mysensorsgw (p2, c1, k15, u'mysensors').
2021-10-12T13:28:54: Client mysensorsgw has exceeded timeout, disconnecting.
I was first powering the Arduino Uno with a normal 12V/1A power supply (I thought 12W should be sufficient). Eventually I found out that if I power the Arduino with a USB-Cable and a USB power supply (= 5V), this issue stops and it did not disconnect. Maybe the step-down converter on the Arduino is not powerful enough to supply the Arduino, W5100 and RFM69HW radio with 5V / 3.3V?
Third (and current) problem is that the range is very poor - the message arrives only if I am in a ~ 5 meter radius around the gateway. I was first suspecting that I have to tweak the MY_RFM69_TX_POWER_DBM setting as described in other articles but even with the default setting it should work better. I suspect that my radio is broken and will try to replace it later this week. To stabilize the power supply to the radio I added a 47 uf capacitor between the 3.3V in for the radio and ground but that did not help. By the way: Why did you add a second 0.1 uf capacitor in parallel to the 47 uf one? Is that a ceramic capacitor with different characteristics?
Best regards,
Daniel