Hi

How do you know the right setting to put the Gyro Update frequency and the PID loop frequency on?

If you are running Betafight 4.2 then the Gyro update frequency gets locked to the native frequency of the gyro (in most cases 8KHz) and you can't change it.

On an F4 FC, if you're running without bi-directional Dshot / RPM filtering you can easily set the PID loop to 8KHz with no issues. However, if you switch on bi-directional Dshot / RPM filtering then you will almost certainly need to lower the PID loop to at least 4K and the Dshot rate to DSHOT300. Follow Voodoo's guide HERE which will help you determine what frequency rates are safe to set based on what load all the tasks are putting on the MCU.

(27-Jun-2020, 09:20 PM)SnowLeopardFPV Wrote: If you are running Betafight 4.2 then the Gyro update frequency gets locked to the native frequency of the gyro (in most cases 8KHz) and you can't change it.

On an F4 FC, if you're running without bi-directional Dshot / RPM filtering you can easily set the PID loop to 8KHz with no issues. However, if you switch on bi-directional Dshot / RPM filtering then you will almost certainly need to lower the PID loop to at least 4K and the Dshot rate to DSHOT300. Follow Voodoo's guide HERE which will help you determine what frequency rates are safe to set based on what load all the tasks are putting on the MCU.

  My HW G3 F4 update frequency won't change from 8000K in Betaflight.Theres no choices as I'm using Betaflight 4.2.
 I switched to bi blades and am getting more prop wash than I had with try blades which wasn't bad just in sharp turns and transitional power out of idle.
 Is there any way to allow me to change from 8000k to 4000K so I can try bi-directional?
   I checked tasks and my max load is 125% when its 8000K so I need to use 4000K and 300Dshot for bi directional if I'm understanding correctly? 
 I'm using BH 2306.5 14magnets and 12 teeth. 
 Is it even possible to change the 8000K to 4000k?

Gyro and PID Loop are 2 settings
Gyro is locked to 8K on BF 4.2
but the PID loop can be changed to 4k if you have an F4 board , that is your case.

on my F4 Matek clone FC, i have BF 4.1.1 as that was the latest i can install on it, no more support for it


Look at this


and




That's the way you set an F4 FC

I'm using HW G3 F4.
So all I need to do is change to 4000K pid loop frequency, set number of magnets to 14,dshot 300, and turn on bi-directional?
where can I find cycle time and cpu load?

(27-May-2021, 04:24 PM)Rob3ddd Wrote: I'm using HW G3 F4.
So all I need to do is change to 4000K pid loop frequency, set number of magnets to 14,dshot 300, and turn on  bi-directional?
where can I find cycle time and cpu load?

You need to type the "tasks" CLI command to see the CPU cycle time / load. I suggest you have a read of Voodoo's excellent thread at the link below...

https://intofpv.com/t-rpm-filtering-setup

My tasks lists reads a bit different.Maybe since I can't change gyro update frequency to 4000K (BF 4.2)my total max load is over 100%.
So this isn't a good candidate for using b-directional or isn't supported in Betaflight 4.2?
I didn’t turn on my radio on so I’ll need to try again with LiPo and radio on.
I may try using betaflight 4.1 just to see what happens and for more clear directions.

# tasks
Task list rate/hz max/us avg/us maxload avgload total/ms
00 - ( SYSTEM) 9 2 0 0.5% 0.0% 0
01 - ( SYSTEM) 996 402 1 40.5% 0.5% 202
02 - ( GYRO) 8000 16 9 13.3% 7.7% 10451
03 - ( FILTER) 4000 30 19 12.5% 8.1% 12110
04 - ( PID) 4000 79 56 32.1% 22.9% 37036
05 - ( ACC) 998 15 9 1.9% 1.3% 1336
06 - ( ATTITUDE) 499 15 8 1.2% 0.8% 647
07 - ( RX) 32 70 42 0.7% 0.6% 223
08 - ( SERIAL) 100 567370 2 5674.2% 0.5% 1405
09 - ( DISPATCH) 998 8 1 1.2% 0.5% 85
10 - (BATTERY_VOLTAGE) 50 4 2 0.5% 0.5% 12
11 - (BATTERY_CURRENT) 50 2 1 0.5% 0.5% 5
12 - ( BATTERY_ALERTS) 5 3 1 0.5% 0.5% 0
13 - ( BEEPER) 100 13 3 0.6% 0.5% 46
20 - ( TELEMETRY) 499 27 0 1.8% 0.0% 290
23 - ( OSD) 60 465 39 3.2% 0.7% 357
25 - ( CMS) 19 4 1 0.5% 0.5% 3
26 - ( VTXCTRL) 5 23 8 0.5% 0.5% 12
27 - ( CAMCTRL) 5 1 1 0.5% 0.5% 0
29 - ( ADCINTERNAL) 1 2 2 0.5% 0.5% 0
30 - ( PINIOBOX) 19 3 1 0.5% 0.5% 2
RX Check Function 8 2 12
Total (excluding SERIAL) 113.5% 47.6%