BF3.3 new filter tuning
Added 2018-03-02 20:34:12 +0000 UTC
Betaflight 3.3 is out and I am editing my video about the new filters NOW. Until then, here is my recommendation:
Set gyro_stage2_lowpass_hz=150
Disable all notch filters: gyro, dterm, and dynamic
Set dterm lowpass to PT1.
Enable 32k sampling if your FC supports it
For F4, run your FC at 32 kHz / 16 kHz. Disable accelerometer to save a few cycles if need be, but you should be okay even with it enabled. I was at about 45% utilization with this setup. The main advantage was disabling dynamic filter, which is very CPU intensive.
Use either Dshot600 or Multishot unsynced at 32 kHz whichever you prefer or your ESCs support. Multishot will give a bit lower CPU utilization.
If you intend to try 32/32, then you must run Dshot1200 or Multishot only. Dshot600 probably won't work even though technically it can.
If you want to tune further, set debug_mode=gyro and look in blackbox at where your motor noise starts coming in. Typically this is somewhere around 300 Hz. Increase the stage2 lowpass to just below your motor noise, but not higher.
If you don't want to fuss with blackbox, raise the stage2 lowpass in increments of maybe 25 or 50 and test for hot motors every time.
If you let stage2 lowpass get too high with d term notch disabled, there is a much increased risk of burning your motors especially if you suddenly damage a prop. Cool motors with perfectly balanced props could still result in burnt motors if you damage a prop. You can easily test this by cutting the tip off a prop or using a beat up chipped up set of props to test.
Comments
Some good shit man
2018-03-03 17:20:28 +0000 UTCIt says PT1 above.
2018-03-03 14:57:46 +0000 UTCPT1 or BIQUAD?
2018-03-03 14:47:43 +0000 UTCThat's not what I said. I said my board can't do 32k gyro rate, but that doesn't mean you can't use the new filters even at 8k.
Joshua Bardwell
2018-03-03 06:11:24 +0000 UTCIn Josh's first Kalman filter video he stated you can't overclock and use the Kalman filters on his Bardwell CLRacingF4 board. Is this the case or has some changed? I have a Bardwell FC which I'd love to see be able to have 32k sampling. If not, what is the next recommended FC I should buy in order to reliably utilize the Kalman filters and 32? Thanks.
2018-03-03 05:54:26 +0000 UTCHi!! Im new here ^^
2018-03-03 05:15:56 +0000 UTCThanks for this Joshua ๐
2018-03-03 02:48:47 +0000 UTCThanks Josh!
2018-03-02 23:39:45 +0000 UTCThanks mate, couldn't be bothered/had the balls to look into doing this untill now, much appreciated JB
2018-03-02 23:31:18 +0000 UTCNo f7 optimization that I know of. Targeted for 3.4.
Joshua Bardwell
2018-03-02 23:13:00 +0000 UTC
