Add Slider Trinkey MIDI example.

Author: kattni

Slider_Trinkey/MIDI_CC_Cross_Fader/code.py

@@ -0,0 +1,81 @@
+import time
+import board
+import analogio
+import usb_midi
+import adafruit_midi
+import neopixel
+from adafruit_midi.control_change import ControlChange
+
+pixels = neopixel.NeoPixel(board.NEOPIXEL, 2, brightness=1)
+
+slider = analogio.AnalogIn(board.POTENTIOMETER)
+position = slider.value  # ranges from 0-65535
+
+
+midi = adafruit_midi.MIDI(
+    midi_in=usb_midi.ports[0], in_channel=0, midi_out=usb_midi.ports[1], out_channel=0
+)
+
+last_cc_val = 0
+
+
+# ------- Hue/Sat/Val function to convert to RGB  ------ #
+def hsv2rgb(h, s, v):
+    """
+    Convert H,S,V in 0-255,0-255,0-255 format
+    to R,G,B in 0-255,0-255,0-255 format
+    Converts an integer HSV (value range from 0 to 255) to an RGB tuple
+    """
+    if s == 0:
+        return v, v, v
+    h = h/255
+    s = s/255
+    v = v/255
+    i = int(h * 6.0)
+    f = (h * 6.0) - i
+    p = v * (1.0 - s)
+    q = v * (1.0 - s * f)
+    t = v * (1.0 - s * (1.0 - f))
+    i = i % 6
+    if i == 0:
+        r, g, b = v, t, p
+    if i == 1:
+        r, g, b = q, v, p
+    if i == 2:
+        r, g, b = p, v, t
+    if i == 3:
+        r, g, b = p, q, v
+    if i == 4:
+        r, g, b = t, p, v
+    if i == 5:
+        r, g, b = v, p, q
+    return int(r * 255), int(g * 255), int(b * 255)
+
+
+hue_a = 0
+sat_a = 255
+val_a = 255
+color_a = hsv2rgb(hue_a, sat_a, val_a)
+
+hue_b = 127
+sat_b = 255
+val_b = 255
+color_b = hsv2rgb(hue_a, sat_a, val_a)
+
+pixels[0] = color_a
+pixels[1] = color_b
+pixels.show()
+
+while True:
+    cc_val = slider.value // 512  # make 0-127 range for MIDI CC
+
+    if abs(cc_val - last_cc_val) > 2:
+        print(cc_val)
+        last_cc_val = cc_val
+        mod_wheel = ControlChange(1, cc_val)
+        midi.send(mod_wheel)
+        color_a = hsv2rgb(cc_val, sat_a, val_a)
+        pixels[0] = color_a
+        color_b = hsv2rgb(cc_val, sat_b, val_b)
+        pixels[1] = color_b
+        time.sleep(0.001)