How to Choose RNode LoRa Parameters
Started by Cleeyv 0b91c6bd3f4e6eda... ·
I actually didnt mean to say that meshcore is using 869.618750, just that the logic behind why they use 869.618 is that the band is split in 4 parts and each center frequencies are then truncated to 3 digits. And if you use a different logic to split it it could result in bands touching.
I am not sure if its a good idea to use the exact center frequency though. Maybe its better to do the rounding beforehand so we are certain that we use the same frequency ^^ I think not all hardware is capable of using more then 3 decimals.
Hm, on the other hand, using those truncated center frequencies with a 62,5khz bandwith also sounds problematic. They would overlap again if the chip actually uses 62.5 and not 62khz.
Well i see the parallel to driving here. If we have 4 lanes, then the user can use any lane, or in-between if the road is empty, no issues with that. But there is traffic so when this happens we each try to stay in our own lane. If a car is designed such that it can't use one lane and it's offcenter, making a mess on 2 lanes at once, then it's the car manufacturer design and responsibility to be decent.
In other words, if the Application doesn't support such granularity, then the devs should fix it. If the HW supports centering it right, then SW should be implemented as such. Else the mess cascades into ruining the fun for everyone.
If the HW does not support this, then yeah it's unfortunate and we do what we can. The user resonsibility should end at choosong the lane reaponsibly and use more bands only when he's sure there is no other traffic on the other lanes.
Guess it makes sense. I will test if its still interoperable (truncated and exact frequency) if yes it would totally make sense to use the exact frequency.
I think that the hardware most are using is also way more inaccurate than we think, and probably the frequencies are way more off in practice then the bits we are discussing here 😅
Anonymous wrote:
Guess it makes sense. I will test if its still interoperable (truncated and exact frequency) if yes it would totally make sense to use the exact frequency.
Reporting back, this works. An RNode with 869556250 and another one with 869556000 had no issues sending data (tested in the same room). So I think its ok to use the exact frequency.