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Hello,
I have an odd issue here and I wonder where to start looking.
I've managed to get dump1090 running on a Fritz!Box DSL router. This is in many ways like a Raspberry Pi, it also runs Linux, but not quite a standard distro (www·freetz·org) and with a big-endian (I think) dual core MIPS CPU instead of ARM. It works, but strangely not as well as on a PC.
On a PC by average I can capture ~20% or so more messages than on the Fritz!Box, using the same cmdline arguments exactly, using the same receiver+antenna installed on the same roof, and I can't think of an obvious explanation. Has anyone else tried this out/seen similar issues?
In both cases, the receiver is connected to the machine through the same 10m USB cable + simple powered USB hub. In both cases it's dump1090_mr compiled from the same source tree (though with different compiler flags, I'll see if -O3 is somehow killing it though this would seem unlikely). Frequency and sample rate are also the same, it's not like it's dropping the sample rate to shed load on this slow CPU.
And really the CPU seems fast enough as dump1090 is running with only 20% CPU utilisation, it could easily spend a little more to try harder. :-D
Since I think the MIPS CPU is running in big-endian mode and PCs + RasPi's are little-endian I wonder whether this could be an issue, but the dump1090 src tree is huge enough that figuring that out is not going to be simple. Does anyone have other ideas of what could cause differences in messages received or at least decoded successfully?
I have an odd issue here and I wonder where to start looking.
I've managed to get dump1090 running on a Fritz!Box DSL router. This is in many ways like a Raspberry Pi, it also runs Linux, but not quite a standard distro (www·freetz·org) and with a big-endian (I think) dual core MIPS CPU instead of ARM. It works, but strangely not as well as on a PC.
On a PC by average I can capture ~20% or so more messages than on the Fritz!Box, using the same cmdline arguments exactly, using the same receiver+antenna installed on the same roof, and I can't think of an obvious explanation. Has anyone else tried this out/seen similar issues?
In both cases, the receiver is connected to the machine through the same 10m USB cable + simple powered USB hub. In both cases it's dump1090_mr compiled from the same source tree (though with different compiler flags, I'll see if -O3 is somehow killing it though this would seem unlikely). Frequency and sample rate are also the same, it's not like it's dropping the sample rate to shed load on this slow CPU.
And really the CPU seems fast enough as dump1090 is running with only 20% CPU utilisation, it could easily spend a little more to try harder. :-D
Since I think the MIPS CPU is running in big-endian mode and PCs + RasPi's are little-endian I wonder whether this could be an issue, but the dump1090 src tree is huge enough that figuring that out is not going to be simple. Does anyone have other ideas of what could cause differences in messages received or at least decoded successfully?
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