Constantly high CPU usage of kelvin on Raspberry Pi Zero about kelvin HOT 6 CLOSED

@stefanwichmann I just updated. It seems that CPU usage has dropped from ~20% to ~6% CPU which is a significant improvement. Thanks!

from kelvin.

Hi Emily,

thanks for giving Kelvin a try!

Sadly the observed behavior is normal when using Kelvin. Currently the Hue bridge has no way of informing users that the state of a light changed. So the only way to realize programs like Kelvin is to ask the bridge for changes again and again... Kelvin currently does this every second for every light! This is why you see a load of 20%... If I would reduce this polling frequency it would take much longer for Kelvin to become active once you turn on a light.

If you feel adventurous and now a little bit about go you can adjust the polling value here: https://github.com/stefanwichmann/kelvin/blob/master/light.go#L45

If you are just concerned about energy consumption I think you should not worry to much. The Raspberry PI Zero is a low power device by design and the CPU isn't the only component using energy. If you take the memory and the wifi chip into consideration, the 20% shouldn't matter to much.

Nevertheless I would love to see a way for Kelvin to consume less energy while maintaining the same level of service. If you have ideas I am all ears! :-)

from kelvin.

Anything C++, and I'm your girl but Go... not really :D

Still, it's a 1 GHz CPU with around 1 IPC so a 20% load for a polling frequency of 1 Hz sounds high to me.

Is there an easy way for me to profile and see where the time is spent? I tried dumping stacks from gdb but that didn't really give much without symbols.

from kelvin.

This blog post provides an introduction to go profiling:

https://blog.golang.org/profiling-go-programs

If you feel like it, give it a try! This help would definitely be very welcome. Can't promise a timeline but will also look into it...

from kelvin.

@stefanwichmann Can we make that light update interval a configurable option? With the 'remember-last-light-state' option in the new firmware update - I don't require my lights to change that much when I switch them on. Also, I have a large number of bulbs at home, to the point where I can't use the mobile app while Kelvin is running.

from kelvin.

Just released Kelvin 1.2.0 which should improve the performance a lot! Especially in setups with many lights... Let me know if it works for you!

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