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stepper-motor-synth
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pitch_table: expand bend to 2048 levels

This commit is contained in:
Peter Cai 2021-06-11 18:56:21 +08:00
parent 7a3f62499f
commit dea29d97fc
2 changed files with 6 additions and 6 deletions
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8
gen_pitch_table.py
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@ -56,13 +56,13 @@ for i in range(start_pitch, end_pitch):
print("};")
print("")
print("// scale factors for bend values from 0 to 255")
print("// scale factors for bend values from 0 to 2047")
print("// We don't support the full 16385 levels of MIDI bend")
print("// MIDI bend values have to be converted first to the nearest supported one")
print("constexpr PROGMEM float midi_pitch_bend_scale[256] = {")
print("constexpr PROGMEM float midi_pitch_bend_scale[2048] = {")
for i in range(0, 256):
factor = pow(2, (8192 - i * 64) / 49152)
for i in range(0, 2048):
factor = pow(2, (8192 - i * 8) / 49152)
print(" " + str(factor) + "f,\t// " + str(i))
print("};")

4
motor_control.cpp
View File

@ -38,8 +38,8 @@ void MotorControl::TickPitchBend(int bend) {
if (bend < 0 || bend >= 16384) return;
if (tick_period_orig_half_micros == 0) return;
// Scale the MIDI bend value down to 0 - 255
bend = bend / 64;
// Scale the MIDI bend value down to 0 - 2047
bend = bend / 8;
tick_period_half_micros = (unsigned long) (((float) tick_period_orig_half_micros) * pgm_read_float_near(midi_pitch_bend_scale + bend * sizeof(float)));
}