What does --my-is-rfm69hw do?

[SquareKinematics]

I have a raspberry pi gateway setup with an RFM69HW radio.

I switched my Raspberry Pi Gateway from MQTT to TCP, and I was met with my only sensor node repeatedly sending find parent messages. It worked only in very close proximity to the gateway.

After a bit of debugging I noticed that I added the --my-is-rfm69hw flag in my transition from MQTT to TCP. After removing this everything resumed normal operation.

What does adding this flag do (my understanding is that is just changes the TX power levels), and why did it drastically reduce the range?

[scalz]

hello,

yes this define is for setting TX power level. when it's not well set, you can get range issue like you experienced.
this is weird because if you're using a rfm69HW you should need it.
or maybe the flag is inverted for the rpi (no idea, i don't use rpi gw).

[gohan]

The flag should be correct as it is, but it could be also that the radio module is not HW (i got some sent as hw but they were actually W only)

[manutremo]

@SquareKinematics If everything was working well before changing fom MQTT to TCP, and the flag was introduced together with that change, then you most likely have a non hw rfm69 module. That flag is only needed when the rfm69 module is hw type.

You can see in this image the differences between the two boards so you can check.

[SquareKinematics]

@manutremo Thank you for that info-graphic. You are and @gohan are correct, I have an RFM69W. This is what I get for buying from the cheapest seller on eBay