09-11-2021, 07:41 PM
I got the needle added to the health meter, thought I would explain what it means.
The program is technically split into 3 programs because it's using multiple threads. One thread is used for all operations that need to happen in real time, this is what the meter is monitoring.
On my system using Pi 3 this thread loops over and over 195 times every second, meaning all systems are checked every loop. I expect a Pi 4 will be faster and a Pi Zero slower.
As mine is running at 195 loops per second I based the meter on 100 loops. 100% means it's running 200 loops or more per second, 0% means it's running less than 100 loops per second which is still extremely fast. I don't expect it should ever get under that so I'll start it here and see how it goes. When lights are fading it will drop but I haven't been monitoring it, if I find it drops more than I like I can speed things up during a fade. If you look carefully you can see the needle isn't flat because I'm only 195 loops not 200+.
![[Image: health.PNG]](https://www.robo-tank.ca/pictures/screenshots_app/Updated_Version/health.PNG)
This is slower than the original controller with the Arduino Due, I believe that was around 300-400 loops per second, unfortunately I don't have the number recorded in the code but I know this is lower.
Does this mean the Raspberry Pi 3 is slower than an Arduino Due? Actually the Arduino is no comparison. If I run the 3rd thread without a throttle it can actually run 52,000 to 55,000 loops per second, that's crazy. Kind of makes the 195 not sound so real time. At full speed the CPU runs at 100% so there's a sleep function that slows it down. Running at 195 it uses about 2-4% of CPU and that's plenty fast enough.
The memory used on the Pi is on the higher side though, mine is using 180mb. The reason this is high is Apache and especially MySQL, I think it alone uses half of that. Pi Zero is 512mb so I think it'll be ok.
The program is technically split into 3 programs because it's using multiple threads. One thread is used for all operations that need to happen in real time, this is what the meter is monitoring.
On my system using Pi 3 this thread loops over and over 195 times every second, meaning all systems are checked every loop. I expect a Pi 4 will be faster and a Pi Zero slower.
As mine is running at 195 loops per second I based the meter on 100 loops. 100% means it's running 200 loops or more per second, 0% means it's running less than 100 loops per second which is still extremely fast. I don't expect it should ever get under that so I'll start it here and see how it goes. When lights are fading it will drop but I haven't been monitoring it, if I find it drops more than I like I can speed things up during a fade. If you look carefully you can see the needle isn't flat because I'm only 195 loops not 200+.
This is slower than the original controller with the Arduino Due, I believe that was around 300-400 loops per second, unfortunately I don't have the number recorded in the code but I know this is lower.
Does this mean the Raspberry Pi 3 is slower than an Arduino Due? Actually the Arduino is no comparison. If I run the 3rd thread without a throttle it can actually run 52,000 to 55,000 loops per second, that's crazy. Kind of makes the 195 not sound so real time. At full speed the CPU runs at 100% so there's a sleep function that slows it down. Running at 195 it uses about 2-4% of CPU and that's plenty fast enough.
The memory used on the Pi is on the higher side though, mine is using 180mb. The reason this is high is Apache and especially MySQL, I think it alone uses half of that. Pi Zero is 512mb so I think it'll be ok.
