From 6a0c72daf6f9d50dc031e8018406388b2591952b Mon Sep 17 00:00:00 2001 From: Ashley Strahle Date: Sat, 9 Mar 2024 08:38:26 +1000 Subject: [PATCH] Update to allow up to 3 expression pedals --- code.py | 92 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 45 insertions(+), 47 deletions(-) diff --git a/code.py b/code.py index 6a5a7a6..1c388ba 100755 --- a/code.py +++ b/code.py @@ -1,8 +1,8 @@ ################################################################################ # -# Pi-Pico-ExpressionPedal2Midi +# Pi-Pico-ExpressionPedal2Midi (Multiple Pedals) # -# using USB midi. Midi messages are sent simultaneoulsy to UART1 and USB. +# Using USB midi. Midi messages are sent simultaneoulsy to UART1 and USB. # Set desired midi channel, change control, and maximum and minimum values # # Upon run/power on, move expresson pedal from maximum to minimum to calibrate @@ -30,69 +30,67 @@ from adafruit_midi.pitch_bend import PitchBend from adafruit_midi.control_change import ControlChange # Midi output settings -midi_channel = 1 # Target midi channel to write to -cc = 1 # Target Control Change number - Expression Pedal -cc_min = 0 # Minimum desired CC output - 0 - 127 -cc_max = 127 # Maximum desired CC output - 0 - 127 +midi_channel = 1 # Target midi channel # Expression pedal settings logarithmic = True # Expression pedal logarithmic or linear. Set to False for linear log_base = 100 # This value changes the feel of the log curve # Required percentage of expression pedal movement for calibration -exp_pedal_calibration_percent = 80 # 0 - 100 +exp_pedal_calibration_percent = 80 # 0 - 100 + +# Define expression pedals +expression_pedals = [ + # Set expression pedal midi control change number, and min/max values + {"pin": board.GP26, "cc": 1, cc_min: 0, cc_max: 127}, # Pedal 1. Pin 31 + {"pin": board.GP27, "cc": 2, cc_min: 0, cc_max: 127}, # Pedal 2. Pin 32 + {"pin": board.GP28, "cc": 3, cc_min: 0, cc_max: 127} # Peadl 3. Pin 34 +] # Devices led = digitalio.DigitalInOut(board.LED) led.direction = digitalio.Direction.OUTPUT -exp = analogio.AnalogIn(board.GP26) # Expression pedal device on pin 31 uart = busio.UART(tx=board.GP4, rx=board.GP5, baudrate=31250, timeout=0.001) # UART Midi device on pin 6 uart_midi = adafruit_midi.MIDI(midi_out=uart, out_channel=midi_channel - 1) usb_midi = adafruit_midi.MIDI( - midi_out=usb_midi.ports[1], out_channel=midi_channel - 1) + midi_out=usb_midi.ports[1], out_channel=midi_channel - 1) + +# Initialize expression pedals +exp_values = [analogio.AnalogIn(pedal["pin"]) for pedal in expression_pedals] +exp_previous = [exp.value for exp in exp_values] +exp_min = [65535 for _ in expression_pedals] +exp_max = [1e-6 for _ in expression_pedals] +exp_calibration_threshold = [int(abs(exp_max[i] - exp_min[i]) * exp_pedal_calibration_percent / 100) for i in range(len(expression_pedals))] # This function translates the expression pedal value to the equivalent CC value -def translate(exp_val): +def translate(exp_val, exp_min, exp_max, cc_min, cc_max): if logarithmic: - scaled_val = math.log(exp_val, log_base) # Apply logarithmic scaling - return int((((scaled_val - math.log(exp_min, log_base)) * (cc_max - cc_min)) / (math.log(exp_max, log_base) - math.log(exp_min, log_base))) + cc_min) + scaled_val = math.log(exp_val, log_base) # Apply logarithmic scaling + return int((((scaled_val - math.log(exp_min, log_base)) * (cc_max - cc_min)) / (math.log(exp_max, log_base) - math.log(exp_min, log_base))) + cc_min) else: - return int((((exp_val - exp_min) * (cc_max - cc_min)) / (exp_max - exp_min)) + cc_min) + return int((((exp_val - exp_min) * (cc_max - cc_min)) / (exp_max - exp_min)) + cc_min) -# Initialise variables -offset = 1e-6 # Small offset to avoid log(0) error - -# Set these to reverse thresholds to enable calibration -exp_min = 65535 -exp_max = offset - -exp_calibration_threshold = int(abs(exp_max - exp_min) * exp_pedal_calibration_percent / 100) -cc_ratio = 1/(cc_max - cc_min) # Calculate number of possible CC values -exp_previous = exp.value - -if exp_previous == 0: - exp_previous = offset - -# main loop +# Main loop while True: - exp_current = exp.value - if exp_current == 0: - exp_current = offset + for i, exp in enumerate(exp_values): + exp_current = exp.value + if exp_current == 0: + exp_current = 1e-6 # Small offset to avoid log(0) error - # Only process if the change ratio is greater than the possible number of CC values - if abs(exp_current - exp_previous) / exp_max > cc_ratio: - if exp_current > exp_max: - exp_max = exp_current - elif exp_current < exp_min: - exp_min = exp_current - exp_previous = exp_current + # Only process if the change ratio is greater than the possible number of CC values + if abs(exp_current - exp_previous[i]) / exp_max[i] > 1/(cc_max[i] - cc_min[i]): + if exp_current > exp_max[i]: + exp_max[i] = exp_current + elif exp_current < exp_min[i]: + exp_min[i] = exp_current + exp_previous[i] = exp_current - # Only send midi when calibration threshold has been reached - if exp_max - exp_min > exp_calibration_threshold: - led.value = True # Turn led on - cc_val = translate(exp_current) - uart_midi.send(ControlChange(cc, cc_val)) - usb_midi.send(ControlChange(cc, cc_val)) - led.value = False # Turn led off - print("Writing Midi Channel: {}, ControlChange: {}, Value {}. Exp Pedal: cur: {}, min: {}, max: {}".format( - midi_channel, cc, cc_val, exp_current, exp_min, exp_max)) \ No newline at end of file + # Only send midi when calibration threshold has been reached + if exp_max[i] - exp_min[i] > exp_calibration_threshold[i]: + led.value = True # Turn led on + cc_val = translate(exp_current, exp_min[i], exp_max[i], cc_min[i], cc_max[i]) + uart_midi.send(ControlChange(expression_pedals[i]["cc"], cc_val)) + usb_midi.send(ControlChange(expression_pedals[i]["cc"], cc_val)) + led.value = False # Turn led off + print("Pedal {}: Writing Midi Channel: {}, ControlChange: {}, Value {}. Exp Pedal: cur: {}, min: {}, max: {}".format( + i + 1, midi_channel, expression_pedals[i]["cc"], cc_val, exp_current, exp_min[i], exp_max[i]))