Category Archives: Uncategorized

Betaflight 3.4 filter parameters

CLI parameter name default value in 3.4
gyro_hardware_lpf NORMAL Filter at the gyro (hardware).
Previously called “gyro_lpf”.
Choices are NORMAL / ADVANCED.
NORMAL = Filter starts from ~250Hz at 8kHz.
EXPERIMENTAL=…
More info
gyro_32khz_hardware_lpf NORMAL
gyro_lowpass_hz 90 aka “Gyro lowpass 1″.
Last in the signal chain for PID (P/I terms, D has filters/notches).Suggested values for gyro_lowpass_hz: Default / Optimal flight performance: 100, Slightly noisy setup: 80,  Very noisy: 50Can be replaced with gyro_lowpass2_hz (with BIQUAD_RC_FIR2 type)
gyro_lowpass_type PT1 Choices:PT1, BIQUAD, BUTTERWORTH, BIQUAD_RC_FIR2, FAST_KALMAN
gyro_lowpass_order 1
gyro_lowpass2_type PT1 Lowpass 2 is right after hardware filter in the signal chain.
gyro_lowpass2_hz 0
gyro_lowpass2_order 1
gyro_notch1_hz 400 Suggested to disable
gyro_notch1_cutoff 300
gyro_notch2_hz 200 Suggested to disable
gyro_notch2_cutoff 100
dterm_lowpass_type BIQUAD Suggested to change to PT1 if used.
Lowpass 1 is feeding signal to dterm chain.Note: profile specific
dterm_lowpass_hz 100 “Dterm lowpass is always needed. Never remove that! Even on the cleanest setup.”
Note: profile specific
dterm_lowpass2_hz 0 “Modelling and logging shows significant reductions in higher frequency Dterm noise with only minor additional delay. Having a configurable setpoint allows the user to tune the least filtering that provides adequate noise reduction.The biquad will provide very effective filtering but greater delay.”More info

Note: profile specific

dterm_notch_hz 260 Can be disabled on clean setups.
Note: profile specific
dterm_notch_cutoff 160 Note: profile specific

betaflight19

Turnigy Graphene 1300 4S (65C) vs CNHL 1300 4S (100C)

Here’s comparison discharge for three Turnigy Graphene batteries compared to CNHL battery. All batteries were fully charged and not used before. The discharge was done with constant 1 ohm load which means 200W of average discharge power. Graphene discharge data is one year ago (February 2017).

Constant 1 ohm discharge, 4S 1300mAh, approx 200W of power

Flight tests, running on T-Motor F60 2200kv and Cyclone T5050C. I estimate the full throttle amperage to be 80A max (because the voltage drops to 12.5V which is 3.1V per cell). Here’s video from punch made with fully charged battery:

Reset NVRAM and SMC

NVRAM
Turn off, turn on, immediately press these 20 seconds:
macos-nvram-p-key
Computer restarts few times during this operation.

SMC
Shut down and unplug power. Hold the Shift, Option, and Control keys on the left side and press the power button and hold keys for 10 seconds, then release.
shif

Musical scales / steps between

2212221;Major
2122221;Minor
2122131;Harmonic Minor
2122221;Melodic Minor
23223;Pentatonic Major
32232;Pentatonic Minor
32113;Pentatonic Blues
2323;Pentatonic Neutral
2212221;Ionian
32122122;Aeolian
2122212;Dorian
2212212;Mixolydian
1222122;Phrygian
2221221;Lydian
1221222;Locrian
1212121;Dim half
2121212;Dim whole
22222;Whole
31313;Augmented
111111111111;Chromatic
2131212;Roumanian Minor
1312122;Spanish Gypsy
321132;Blues
22323;Diatonic
1312131;Double Harmonic
12111222;Eight Tone Spanish
1322211;Enigmatic
222211;Leading Whole Tone
2222121;Lydian Augmented
1222221;Neoploitan Major
1222122;Neopolitan Minor
12341;Pelog
222312;Prometheus
132312;Prometheus Neopolitan
131313;Six Tone Symmetrical
1212222;Super Locrian
2221122;Lydian Minor
2131122;Lydian Diminished
211211121;Nine Tone Scale
21212121;Auxiliary Diminished
222222;Auxiliary Augmented
12121212;Auxiliary Diminished Blues
2211222;Major Locrian
2221212;Overtone
1212222;Diminished Whole Tone
2122122;Pure Minor
232212;Dominant 7th

Chords in minor scale

Minor scale chords

Columns: First 7 columns are notes in scale (first column is the scale key). Next 7 columns are chords in that scale.

C;D;D#;F;G;G#;A#;Cm;D_dim;D#;Fm;Gm;G#;A#
C#;D#;E;F#;G#;A;B;C#m;D#_dim;E;F#m;G#m;A;B
D;E;F;G;A;A#;C;Dm;E_dim;F;Gm;Am;A#;C
D#;F;F#;G#;A#;B;C#;D#m;F_dim;F#;G#m;A#m;B;C#
E;F#;G;A;B;C;D;Em;F#_dim;G;Am;Bm;C;D
F;G;G#;A#;C;C#;D#;Fm;G_dim;G#;A#m;Cm;C#;D#
F#;G#;A;B;C#;D;E;F#m;G#_dim;A;Bm;C#m;D;E
G;A;A#;C;D;D#;F;Gm;A_dim;A#;Cm;Dm;D#;F
G#;A#;B;C#;D#;E;F#;G#m;A#_dim;B;C#m;D#m;E;F#
A;B;C;D;E;F;G;Am;B_dim;C;Dm;Em;F;G
A#;C;C#;D#;F;F#;G#;A#m;C_dim;C#;D#m;Fm;F#;G#
B;C#;D;E;F#;G;A;Bm;C#_dim;D;Em;F#m;G;A

What does Chorus and Flanger do?

Chorus samples the input, slightly detunes it and mixes it with the original signal to produce a somewhat thicker, shimmering sound. Use it to thicken up background vocals, or to double the sound of brass and woodwind instruments. (source Behringer DeepMind 12 manual) The effect can be achieved by using multiple, slightly detuned oscillators for each note (source).
Flanger emulates the phase-shifting sound (comb-filtering) originally created by applying pressure against the flange of the reel on a tape recorder. This effect creates a unique “wobbly” sound that is quite dramatic when used on vocals and instruments. (source Behringer DeepMind 12 manual). From wikipedia: Flanging /ˈflændʒɪŋ/ is an audio effect produced by mixing two identical signals together, one signal delayed by a small and gradually changing period, usually smaller than 20 milliseconds. This produces a swept comb filter effect: peaks and notches are produced in the resulting frequency spectrum, related to each other in a linear harmonic series. Varying the time delay causes these to sweep up and down the frequency spectrum. A flanger is an effects unit that creates this effect.