smurphy
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Raspberry Pi: Yes
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Post by smurphy on Dec 3, 2020 23:53:13 GMT -8
Just wondering - as my weather rack seems to actually do that. it is the second time I tend to have the feeling that it won't show anything faster.
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Post by SDL on Dec 4, 2020 7:50:13 GMT -8
Lots of parameters here. Speed of your Raspberry PI, delays in the program, other programs running.
Eventually, the response speed of the Pi to an interrupt from the anemometer will hit a limit. I would think it would be higher than 60km/hour, but it's a complex dynamic.
What are you running on your Pi and which Pi is it?
BP
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smurphy
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Post by smurphy on Dec 4, 2020 7:53:14 GMT -8
Raspberry PI zero W and it runs solely the weatherpi software and a small webserver to recover the weatherstats file (text). Load of the PI not high: top - 16:51:31 up 4 days, 16:47, 1 user, load average: 0.17, 0.17, 0.17
Tasks: 71 total, 1 running, 70 sleeping, 0 stopped, 0 zombie
%Cpu(s): 16.0 us, 28.0 sy, 0.0 ni, 56.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 368.7 total, 91.5 free, 76.9 used, 200.3 buff/cache
MiB Swap: 0.0 total, 0.0 free, 0.0 used. 218.4 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
17702 pi 20 0 5588 2568 2144 R 10.0 0.7 0:00.09 top
413 root 20 0 11504 1908 1684 S 5.0 0.5 586:21.92 pigpiod
1 root 20 0 33672 7928 6388 S 0.0 2.1 0:22.19 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.52 kthreadd
6 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 mm_percpu_wq
7 root 20 0 0 0 0 S 0.0 0.0 2:41.65 ksoftirqd/0
8 root 20 0 0 0 0 S 0.0 0.0 0:00.01 kdevtmpfs
9 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 netns At the end of the page: stargate.solsys.org/mod.php?mod=systat&op=list&host=11 you can also see that the pi has barely load on it. |
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smurphy
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Post by smurphy on Dec 27, 2020 4:43:49 GMT -8
Someone having a faster raspberry PI (using a Pi Zero HW) or another device, any chance you could check out if your weather-station has recorded winds faster than 60Km? Again a windy day - and wind speed limit visible @ 60Km/h
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Post by frenchie on Dec 27, 2020 9:40:28 GMT -8
Hi Smurphy, I am using a Raspberry 4B. Wind speed is registered on wunderground. please take a look. It did show a gust upto 142km/hr. Not sure if this is true ! www.wunderground.com/dashboard/pws/ICHANT5Cheers, |
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smurphy
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Post by smurphy on Dec 27, 2020 12:00:04 GMT -8
Thanks for the info. So I guess I'll have to put a faster raspberry PI inside.
Dunno if a P4 will be it, as it gets very warm in summer over here.
Eventually latest gen and underclocking it would do.
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smurphy
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Post by smurphy on Oct 21, 2021 0:07:39 GMT -8
@sdl here - is there a known method to speed up interrupts on the PI zero? Or - which Raspberry PI did you guys use when developing the SkyWeather kit?
We had storm here and I know that we had windspeeds reaching 170Km/h, yet my weatherstation tops at 60Km/h... According to the linpack Benchmark (Designed to highlight a real-world bottleneck, the Python GPIO benchmark switches a single pin on and off while a frequency counter measures how quickly the pin is toggled. The faster a Pi’s processor, the faster the pin can be toggled before the processor hits its limit) it seems the PI4 would be the best bet.
Note that the raspberry PI Zero W I use can poll the GPIO 63times according to this graph - which coincides strongly with the 60Km/h speed it maxes out.
@frenchi - did you underclock yours? IMHO, that should be usable even at half speed.
I may check it out when I service my setup the next time.
To Anyone: have a Raspberry PI 2 with the skyweather? Any issues with the Wind speed measurements?
Don't want to use a PI 4 for a weatherstation (way overkill). I don't want to take the PI 3 as that one is known to become very hot. And The 4 - well, it is overkill at best.
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Post by SDL on Oct 23, 2021 8:59:44 GMT -8
I think that is a good analysis. Faster the Pi, the better the interrupt response. Even though I kind of hate suggesting it, but using the newer SkyWeather2 with WeatherRack2 completely removes this problem.  BP |
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smurphy
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Post by smurphy on Nov 2, 2021 3:47:26 GMT -8
I'll probably go for the skyweather 2 as I have a house in the south I'd like to connect. This will not fix the issue of my current station. I'll eventually grab one of the new Raspberry PI Zero W 2 that just came out and put it in. New CPU (4cores) and faster. That should do it  |
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smurphy
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Post by smurphy on Nov 13, 2021 2:33:15 GMT -8
So - just to confirm that the PI Zero 2 W works.
It requires a full update to the underlying OS though, or else it will not find the WiFi drivers.
Just make sure you do not remove the python 2 libraries, and it runs smooth.
Now - I'll have to wait for the next Storm to see if it can gather the data fast enough to show wind-speed higher than 60Km/h.
PS: The Raspberry PI Zero 2 W is about 4 times faster than the PI Zero 1, has 4 cores which are running also faster (1Ghz) than the single-core (700Mhz) on the PI Zero. And according to tests I had seen somewhere on the net, the GPIO poll speed has increased by a factor of 5 (which made me actually go for it). So my hopes are high.
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Post by SDL on Nov 16, 2021 18:24:15 GMT -8
Outstanding! Your results verify my theory. Do you have power date on the Pi Zero2W?
John
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smurphy
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Post by smurphy on Nov 17, 2021 0:18:13 GMT -8
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Post by SDL on Nov 17, 2021 14:02:51 GMT -8
Ah, your link gave me exactly what I wanted. The loaded power is about 2x the Pi Zero w. The idle current is about the same, which is good. So there is an impact to a solar system, but it is still about 40% of the impact of a 4B+ loaded. I like it! John  |
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smurphy
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Post by smurphy on Feb 18, 2022 0:35:28 GMT -8
So. After having had a storm, I come to the conclusion that something else is limiting the speed readings when using the raspberry PI Zero 2W is in use.  Any idea what to try next? |
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Post by SDL on Feb 20, 2022 11:51:47 GMT -8
Have you looked through the code for the WeatherRack?
BP
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