Crank USB hid code

Crank USB hid code

Author: djecken

Crank_USB_HID/code.py

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+"""
+A CircuitPython 'crank' USB HID demo
+Uses a ItsyBitsy M0 + Rotary Encoder -> USB HID keyboard
+"""
+
+import board
+from digitalio import DigitalInOut, Direction, Pull
+from adafruit_hid.keyboard import Keyboard
+from adafruit_hid.keycode import Keycode
+from adafruit_hid.consumer_control import ConsumerControl
+from adafruit_hid.consumer_control_code import ConsumerControlCode
+
+# Encoder button is a digital input with pullup on D9
+button = DigitalInOut(board.D9)
+button.direction = Direction.INPUT
+button.pull = Pull.UP
+
+# Rotary encoder inputs with pullup on D10 & D11 on ItsyBitsy
+rot_a = DigitalInOut(board.D10)
+rot_a.direction = Direction.INPUT
+rot_a.pull = Pull.UP
+rot_b = DigitalInOut(board.D11)
+rot_b.direction = Direction.INPUT
+rot_b.pull = Pull.UP
+
+# Used to do HID output, see below
+kbd = Keyboard()
+
+######################### MAIN LOOP ##############################
+
+# the counter counts up and down, it can roll over! 16-bit value
+encoder_counter = 0
+# direction tells you the last tick which way it went
+encoder_direction = 0
+
+# constants to help us track what edge is what
+A_POSITION = 0
+B_POSITION = 1
+UNKNOWN_POSITION = -1  # initial state so we know if something went wrong
+
+rising_edge = falling_edge = UNKNOWN_POSITION
+
+# get initial/prev state and store at beginning
+last_button = button.value
+rotary_prev_state = [rot_a.value, rot_b.value]
+
+while True:
+    # reset encoder and wait for the next turn
+    encoder_direction = 0
+
+    # take a 'snapshot' of the rotary encoder state at this time
+    rotary_curr_state = [rot_a.value, rot_b.value]
+
+    if rotary_curr_state != rotary_prev_state:
+        #print("Changed")
+        if rotary_prev_state == [True, True]:
+            # we caught the first falling edge!
+            if not rotary_curr_state[A_POSITION]:
+                #print("Falling A")
+                falling_edge = A_POSITION
+            elif not rotary_curr_state[B_POSITION]:
+                #print("Falling B")
+                falling_edge = B_POSITION
+            else:
+                # uhh something went deeply wrong, lets start over
+                continue
+
+        if rotary_curr_state == [True, True]:
+            # Ok we hit the final rising edge
+            if not rotary_prev_state[B_POSITION]:
+                rising_edge = B_POSITION
+                # print("Rising B")
+            elif not rotary_prev_state[A_POSITION]:
+                rising_edge = A_POSITION
+                # print("Rising A")
+            else:
+                # uhh something went deeply wrong, lets start over
+                continue
+
+            # check first and last edge
+            if (rising_edge == A_POSITION) and (falling_edge == B_POSITION):
+                encoder_counter -= 1
+                encoder_direction = -1
+                print("%d dec" % encoder_counter)
+            elif (rising_edge == B_POSITION) and (falling_edge == A_POSITION):
+                encoder_counter += 1
+                encoder_direction = 1
+                print("%d inc" % encoder_counter)
+            else:
+                # (shrug) something didn't work out, oh well!
+                encoder_direction = 0
+
+            # reset our edge tracking
+            rising_edge = falling_edge = UNKNOWN_POSITION
+
+    rotary_prev_state = rotary_curr_state
+
+    # Check if rotary encoder went up
+    if encoder_direction == 1:
+        ConsumerControl().send(ConsumerControlCode.VOLUME_DECREMENT) #Volume Down
+    #    kbd.press(Keycode.LEFT_ARROW)
+    #    kbd.release_all()
+
+    # Check if rotary encoder went down
+    if encoder_direction == -1:
+        ConsumerControl().send(ConsumerControlCode.VOLUME_INCREMENT) #Volume Up
+    #    kbd.press(Keycode.RIGHT_ARROW)
+    #    kbd.release_all()
+
+    # Button was 'just pressed'
+    if (not button.value) and last_button:
+        print("Button pressed!")
+        kbd.press(Keycode.SPACE) #Keycode for space bar
+        kbd.release_all()
+
+    elif button.value and (not last_button):
+        print("Button Released!")