Merge pull request #1996 from jedgarpark/rotary-phone-keypad

Rotary phone USB hid input first commit

Author: TheKitty

Rotary_Phone_Keypad/boot.py

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+# SPDX-FileCopyrightText: 2022 Tod Kurt & John Park for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+#
+# boot.py to enable or disable usb_hid
+import usb_hid
+import board
+import digitalio
+
+# set a pull-up
+# If not pressed, the key will be at +V (due to the pull-up)
+button = digitalio.DigitalInOut(board.D2)
+button.pull = digitalio.Pull.UP
+
+# Disable devices only if button is not pressed
+# Phone receiver is normally open when handset is in place
+if button.value:
+    print("USB HID disabled")
+    usb_hid.disable()

Rotary_Phone_Keypad/code.py

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+# SPDX-FileCopyrightText: 2022 Tod Kurt & John Park for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+#
+# Rotary phone USB keypad
+
+import time
+import board
+import digitalio
+import microcontroller
+import usb_hid
+from adafruit_hid.keyboard import Keyboard
+from adafruit_hid.keycode import Keycode
+from adafruit_debouncer import Debouncer
+import neopixel
+
+
+dial_in = digitalio.DigitalInOut(board.RX)  # normally closed pulse dial switch
+dial_in.pull = digitalio.Pull.UP
+dial = Debouncer(dial_in)
+
+receiver_in = digitalio.DigitalInOut(board.D2)  # normally open receiver switch
+receiver_in.pull = digitalio.Pull.UP
+receiver = Debouncer(receiver_in)
+
+
+# check if usb_hid has been enabled in boot.py
+if len(usb_hid.devices) == 0:
+    on_hook = True
+    print("on hook")
+else:
+    kbd = Keyboard(usb_hid.devices)
+    on_hook = False
+    print("off hook")
+
+keymap = [
+          Keycode.ONE,
+          Keycode.TWO,
+          Keycode.THREE,
+          Keycode.FOUR,
+          Keycode.FIVE,
+          Keycode.SIX,
+          Keycode.SEVEN,
+          Keycode.EIGHT,
+          Keycode.NINE,
+          Keycode.ZERO
+]
+
+def read_rotary_dial_pulses(timeout=0.2):  # 0.2 is proper timing for pulses
+    dial.update()
+    if not dial.rose:  # NC dial pin is pulled low normally, high when open
+        return 0
+    pulse_count = 1
+    last_pulse_time = time.monotonic()
+
+    while time.monotonic() - last_pulse_time < timeout:  # count pulses that are within 0.2sec
+        dial.update()
+        if dial.rose:
+            pulse_count = pulse_count+1
+            last_pulse_time = time.monotonic()
+
+    return pulse_count
+
+pixel = neopixel.NeoPixel(board.NEOPIXEL, 1)
+
+
+print("Rotary phone USB keypad")
+
+
+while True:
+    receiver.update()
+    if receiver.fell:  # only dial when receiver is off hook
+        print("Off hook")
+        pixel[0] = 0x00ff00
+        microcontroller.reset()  # the boot.py enables usb_hid if off hook
+
+    if receiver.rose:
+        print("On hook")
+        pixel[0] = 0xff0000
+        microcontroller.reset()  # the boot.py disables usb_hid if on hook
+
+    # if not on_hook:
+    num_pulses = read_rotary_dial_pulses()
+    if num_pulses:
+        print("pulse count:", num_pulses)
+        if not on_hook:
+            kbd.send(keymap[num_pulses-1])