Doomscroll and Chill - A Wireless BLE Scroll Wheel Remote

299

2022-07-21 | By Adafruit Industries

License: See Original Project 3D Printing Wearables

Guide by Liz Clark

Overview

A keyboard and a mouse are great tools for navigating your computer, ‎but they require you to stay near your computer. In this project, you ‎can build a wireless BLE controller with common shortcuts ‎programmed for controlling your streaming apps and yes it can even ‎play Doom!‎

The rotary encoder/scroll wheel controller is housed in a 3D printed ‎case. The case has holes at the top so that it can be used as a pendant. ‎This way, you won't lose it, you can access it quickly and you can show ‎off your fashion sense by showcasing the aesthetically pleasing ANO ‎Directional Navigation and Scroll Wheel Rotary Encoder.‎

case_1

The brain of the project is a Feather nRF52840 running CircuitPython. ‎This board has BLE so you can connect to your computer wirelessly.‎

brain_2

The control interface is an ANO Directional Navigation and Scroll Wheel ‎Rotary Encoder. This lets you have a lot of interface options in a small ‎and ergonomic footprint.‎

control_3

There are two switches in the circuit. The switch on the bottom is an ‎on/off switch. The switch on the side is a mode switch to select ‎between streaming mode or Doom mode. Each mode has different ‎keyboard shortcuts that are assigned to the rotary encoder's buttons ‎and scroll wheel.‎

switch_4

Prerequisite Guides

Introducing the Adafruit nRF52840 Feather

ANO Directional Navigation and Scroll Wheel Rotary Encoder and ‎Breakout

BLE HID Keyboard Buttons with CircuitPython

Parts

Adafruit Feather nRF52840 Express
ANO Directional Navigation and Scroll Wheel Rotary Encoder
Adafruit ANO Rotary Navigation Encoder Breakout PCB
Breadboard-friendly SPDT Slide Switch
Lithium Ion Polymer Battery - 3.7v 500mAh‎
Header Kit for Feather - 12-pin and 16-pin Female Header Set‎
1 x Black Nylon Machine Screw and Stand-off Set – M2.5 Thread
‎3 x Silicone Cover Stranded-Core Wire - 30AWG in Various Colors‎

Circuit Diagram

diagram_5

Wiring

ANO Directional Navigation and Scroll Wheel Rotary ‎Encoder
- ENCA to board SDA
- ENCB to board SCL
- COMA to board pin 5
- SW1 to board pin 6
- SW2 to board pin 9
- SW3 to board pin 10‎
- SW4 to board pin 11
- SW5 to board pin 12
- COMB to board pin 13
‎Mode Slide Switch
- Switch pin 1 to board GND
- Switch pin 2 to board pin A1
‎Power Slide Switch
- Switch pin 1 to board GND
- Switch pin 2 to board EN

The rotary encoder has the perfect number of pins to slot into socket ‎headers on the Feather nRF52840. The two slide switches are each ‎soldered to the Feather nRF52840 with two pieces of wire.‎

rotary_6

‎3D Printing‎

printing_7

The controller may be housed in a 3D printed case, described below. ‎The case consists of three parts: a mounting bracket, a top lid, and a ‎main body. All parts print with no supports.‎

The STL files can be downloaded directly here or from Thingiverse.‎

Thingiverse download

bleRotaryControllerSTL.zip

The rotary encoder's breakout PCB and Feather nRF52840 attach to the ‎mounting bracket. The mounting bracket attaches to the mounting ‎holes in the case's lid.‎

The lid snap fits onto the main body of the case. ‎

bracket_8

The main body of the case has cutouts for the two switches. There is ‎enough room to fit a LiPo battery. Additionally, it has holes to run a ‎chain or string through it to wear it as a pendant.‎

lid_9

CircuitPython for Feather ‎nRF52840‎

CircuitPython is a derivative of MicroPython designed to simplify ‎experimentation and education on low-cost microcontrollers. It makes ‎it easier than ever to get prototyping by requiring no upfront desktop ‎software downloads. Simply copy and edit files on the CIRCUITPY drive ‎to iterate.‎

The following instructions will show you how to install CircuitPython. If ‎you've already installed CircuitPython but are looking to update it or ‎reinstall it, the same steps work for that as well!‎

Set up CircuitPython Quick Start!‎

Follow this quick step-by-step for super-fast Python power 😊

Download the latest version of CircuitPython for this board via ‎CircuitPython.org

Click the link above to download the latest UF2 file.‎‎ ‎

Download and save it to your desktop (or wherever is handy).‎

download_10

Plug your Feather nRF52840 into your computer using a known-good ‎USB cable.‎

A lot of people end up using charge-only USB cables and it is ‎very frustrating! So, make sure you have a USB cable you know ‎is good for data sync.‎

Double-click the Reset button next to the USB connector on your ‎board, and you will see the NeoPixel RGB LED turn green (identified by ‎the arrow in the image). If it turns red, check the USB cable, try ‎another USB port, etc. Note: The little red LED next to the USB ‎connector will pulse red. That's ok!‎

If double-clicking doesn't work the first time, try again. Sometimes it ‎can take a few tries to get the rhythm right!‎

reset_11

You will see a new disk drive appear called FTHR840BOOT.‎

Drag the adafruit_circuitpython_etc.uf2 file to FTHR840BOOT.‎

disk_12

drag_13

The LED will flash. Then, the FTHR840BOOT drive will disappear, and ‎a new disk drive called CIRCUITPY will appear.‎‎ ‎

That's it, you're done! :)‎

flash_14

Coding the Wireless BLE Encoder ‎Remote

Once you've finished setting up your Feather nRF52840 with ‎CircuitPython, you can access the code and necessary libraries by ‎downloading the Project Bundle.‎

To do this, click on the Download Project Bundle button in the ‎window below. It will download as a zipped folder.‎

‎Download Project Bundle‎

Copy Code

# SPDX-FileCopyrightText: 2022 Liz Clark for Adafruit Industries
#
# SPDX-License-Identifier: MIT

import board
from digitalio import DigitalInOut, Direction, Pull
import rotaryio
from adafruit_debouncer import Button
from adafruit_hid.keyboard import Keyboard
from adafruit_hid.keycode import Keycode
import adafruit_ble
from adafruit_ble.advertising import Advertisement
from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
from adafruit_ble.services.standard.hid import HIDService

#  pin assignments for the rotary encoder
ENCA = board.SDA
ENCB = board.SCL
COMA = board.D5
CENTER = board.D6
RIGHT = board.D9
UP = board.D10
LEFT = board.D11
DOWN = board.D12
COMB = board.D13

#  mode slide switch pin
SWITCH = board.A1

# Rotary encoder setup
encoder = rotaryio.IncrementalEncoder(ENCA, ENCB)
last_position = 0

# setting the COMA and COMB pins to LOW aka GND
com_a = DigitalInOut(COMA)
com_a.switch_to_output()
com_a = False
com_b = DigitalInOut(COMB)
com_b.switch_to_output()
com_b = False

#  mode switch setup
SWITCH = DigitalInOut(board.A1)
SWITCH.direction = Direction.INPUT
SWITCH.pull = Pull.UP

#  encoder button pins
enc_buttons = (
    CENTER,
    UP,
    LEFT,
    DOWN,
    RIGHT,
)

#  array for the encoder buttons
inputs = []

#  setting the encoder buttons as inputs
for enc in enc_buttons:
    enc_button = DigitalInOut(enc)
    enc_button.pull = Pull.UP
	#  adding to the inputs array with the Button Class of the Debouncer lib
    inputs.append(Button(enc_button))

#  streaming mode keycodes
CHILL_CODES = (
    Keycode.SPACE,
    Keycode.F,
    Keycode.LEFT_ARROW,
    Keycode.M,
    Keycode.RIGHT_ARROW,
)

#  doom mode keycodes
DOOM_CODES = (
    Keycode.CONTROL,
    Keycode.UP_ARROW,
    Keycode.LEFT_ARROW,
    Keycode.DOWN_ARROW,
    Keycode.RIGHT_ARROW,
)

#  streaming state
chill = True
#  doom state
doom = False

#  BLE HID setup
hid = HIDService()

advertisement = ProvideServicesAdvertisement(hid)
advertisement.appearance = 961
scan_response = Advertisement()
scan_response.complete_name = "CircuitPython HID"

#  BLE instance
ble = adafruit_ble.BLERadio()

#  keyboard HID setup
kbd = Keyboard(hid.devices)

#  BLE advertisement
if not ble.connected:
    print("advertising")
    ble.start_advertising(advertisement, scan_response)
else:
    print("connected")
    print(ble.connections)

while True:
	#  check for BLE connection
    while not ble.connected:
        pass
	#  while BLE connected
    while ble.connected:
		#  mode switch
		#  selects whether to be in streaming mode or doom mode
		#  affects the keycodes assigned to the encoder's inputs
        if not SWITCH.value:
            chill = False
            doom = True
        if SWITCH.value:
            chill = True
            doom = False

		#  rotary encoder position tracking
        position = encoder.position
		#  if the encoder is turned to the right
        if position > last_position:
			#  if in streaming mode
            if chill:
				#  send UP arrow for volume
                kbd.send(Keycode.UP_ARROW)
			#  if in doom mode
            if doom:
				#  send period for right strafe
                kbd.send(Keycode.PERIOD)
			#  reset encoder position
            last_position = position
		#  if the encoder is turned to the left
        if position < last_position:
            #  if in streaming mode
            if chill:
				#  send DOWN arrow for volume
                kbd.send(Keycode.DOWN_ARROW)
			#  if in doom mode
            if doom:
				#  send comma for left strafe
                kbd.send(Keycode.COMMA)
			#  reset encoder position
            last_position = position

		#  for loop for keycodes
        for i in range(5):
			#  update state of the buttons
            inputs[i].update()
			#  if you press the center button for a long press
            if inputs[0].long_press:
				#  sends space key
				#  used in Doom for use/open
                kbd.send(Keycode.SPACE)
			#  if a press is detected...
            if inputs[i].pressed:
				#  if in streaming mode
                if chill:
					#  send the streaming keycodes
                    kbd.press(CHILL_CODES[i])
				#  if in doom mode
                if doom:
					#  send the doom keycodes
                    kbd.press(DOOM_CODES[i])
			#  if a button is released...
            if inputs[i].released:
				#  if in streaming mode
                if chill:
					#  release the streaming keycodes
                    kbd.release(CHILL_CODES[i])
				#  if in doom mode
                if doom:
					#  release the doom keycodes
                    kbd.release(DOOM_CODES[i])

	#  if BLE disconnects, begin advertising again
    ble.start_advertising(advertisement)

View on GitHub

Upload the Code and Libraries to the Feather ‎nRF52840‎

After downloading the Project Bundle, plug your Feather nRF52840 into ‎the computer's USB port with a known good USB data power cable. ‎You should see a new flash drive appear in the computer's File Explorer ‎or Finder (depending on your operating system) called CIRCUITPY. ‎Unzip the folder and copy the following items to the Feather ‎nRF52840's CIRCUITPY drive. ‎

lib folder
code.py

Your Feather nRF52840 CIRCUITPY drive should look like this after ‎copying the lib folder and the code.py file.‎

drive_15

How the CircuitPython Code Works

The rotary encoder's five buttons are setup as inputs using ‎the Button class of the adafruit_debouncer library. The adafruit_debouncer library ‎is being used so that the long_press property can be used in the loop.‎

‎Download File‎

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#  encoder button pins
enc_buttons = (
    CENTER,
    UP,
    LEFT,
    DOWN,
    RIGHT,
)

#  array for the encoder buttons
inputs = []

#  setting the encoder buttons as inputs
for enc in enc_buttons:
    enc_button = DigitalInOut(enc)
    enc_button.pull = Pull.UP
	#  adding to the inputs array with the Button Class of the Debouncer lib
    inputs.append(Button(enc_button))

‎Keycodes

There are two sets of keycodes depending on the mode of the remote. ‎The keycodes in CHILL_CODES are for streaming media, such as Netflix or ‎YouTube. The keycodes in DOOM_CODES are for playing classic Doom. The ‎keycode indexes align with the encoder buttons array's indexes. For ‎example, the CENTER button will send the SPACE or CONTROL keycode, ‎depending on the mode.‎

‎Download File‎

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#  streaming mode keycodes
CHILL_CODES = (
    Keycode.SPACE,
    Keycode.F,
    Keycode.LEFT_ARROW,
    Keycode.M,
    Keycode.RIGHT_ARROW,
)

#  doom mode keycodes
DOOM_CODES = (
    Keycode.CONTROL,
    Keycode.UP_ARROW,
    Keycode.LEFT_ARROW,
    Keycode.DOWN_ARROW,
    Keycode.RIGHT_ARROW,
)

The Loop

Once a BLE connection has been established, the loop checks the value ‎of SWITCH to determine the mode of the controller.‎

Download File

Copy Code

while ble.connected:
		#  mode switch
		#  selects whether to be in streaming mode or doom mode
		#  affects the keycodes assigned to the encoder's inputs
        if not SWITCH.value:
            chill = False
            doom = True
        if SWITCH.value:
            chill = True
            doom = False

Encoder Position

The encoder also sends a keycode depending on the mode. The loop ‎checks to see if the encoder is turning to the left or right. Depending ‎on the direction, a keycode will be sent. ‎

In streaming mode, the encoder controls volume. In Doom, it controls ‎left and right strafe.‎

‎Download File

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#  rotary encoder position tracking
        position = encoder.position
		#  if the encoder is turned to the right
        if position > last_position:
			#  if in streaming mode
            if chill:
				#  send UP arrow for volume
                kbd.send(Keycode.UP_ARROW)
			#  if in doom mode
            if doom:
				#  send period for right strafe
                kbd.send(Keycode.PERIOD)
			#  reset encoder position
            last_position = position
		#  if the encoder is turned to the left
        if position < last_position:
            #  if in streaming mode
            if chill:
				#  send DOWN arrow for volume
                kbd.send(Keycode.DOWN_ARROW)
			#  if in doom mode
            if doom:
				#  send comma for left strafe
                kbd.send(Keycode.COMMA)
			#  reset encoder position
            last_position = position

Sending Keycodes

The adafruit_debouncer library checks the status of the button inputs ‎using update(). A for statement is used to iterate through all five buttons. ‎If the center button receives a long_press, then the SPACE keycode is sent. ‎This is used in Doom for the use/open control.‎

Otherwise, the for statement checks to see if a button has ‎been pressed or released. If a button is pressed, then the corresponding ‎keycode is pressed depending on the mode. If a button is released, then ‎the corresponding keycode is released depending on the mode.‎

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#  for loop for keycodes
        for i in range(5):
			#  update state of the buttons
            inputs[i].update()
			#  if you press the center button for a long press
            if inputs[0].long_press:
				#  sends space key
				#  used in Doom for use/open
                kbd.send(Keycode.SPACE)
			#  if a press is detected...
            if inputs[i].pressed:
				#  if in streaming mode
                if chill:
					#  send the streaming keycodes
                    kbd.press(CHILL_CODES[i])
				#  if in doom mode
                if doom:
					#  send the doom keycodes
                    kbd.press(DOOM_CODES[i])
			#  if a button is released...
            if inputs[i].released:
				#  if in streaming mode
                if chill:
					#  release the streaming keycodes
                    kbd.release(CHILL_CODES[i])
				#  if in doom mode
                if doom:
					#  release the doom keycodes
                    kbd.release(DOOM_CODES[i])

Wiring

wiring_16

Rotary Encoder and Breakout Board

Soldering the rotary encoder to the breakout PCB. Then, solder nine ‎pin headers to the breakout PCB's pins.‎

soldering_17

Feather Socket Headers

Trim a row of socket headers to nine sockets. These will be used to ‎plug the rotary encoder into the Feather nRF52840.‎

socket_19

socket_20

socket_18

Solder the trimmed socket header to the Feather nRF52840, beginning ‎with pin 13. Pins Bat, EN, and USB should remain unsoldered. After ‎soldering, the rotary encoder's breakout can plug directly into the ‎Feather.‎

solder_21

solder_22

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Wire Connections

Cut and strip four pieces of wire. Use three different colors to ‎differentiate the connections.‎

Two pieces in color 1 (black): GND connections
One in piece in color 2 (blue): pin A1
One piece in color 3 (yellow): pin EN

wire_24

Twist two pieces of wire together for the GND connection. Solder the ‎wires into the GND pin on the Feather nRF52840.‎

twist_25

twist_26

twist_27

Solder the blue wire to pin A1. This will be the input for the mode ‎switch.‎

Solder the yellow wire to pin EN. This will be the on/off switch ‎connection.‎

yellow_28

Tin the ends of each piece of wire with solder.‎

tin_29

Cut four pieces of heat shrink. Place one piece onto each wire.‎

cut_30

cut_31

Switches

Solder a GND wire to pin 1 on the on/off switch. Solder the yellow wire ‎to the center pin on the on/off switch. The on/off switch should be ‎connected to pin EN.‎

connect_32

Solder a GND wire to pin 1 on the mode switch. Solder the blue wire to ‎the center pin on the mode switch. The mode switch should be ‎connected to pin A1.‎

gnd_33

Apply the heat shrink to the switches' pins to prevent any shorts.‎

switch33a

That completes the soldering for this project!‎

completes_34

Assembly

assembly_35

Mounting Bracket

Attach three M2.5 stand-offs with M2.5 nuts in three of the Feather ‎nRF52840's mounting holes. The mounting hole at the back of the ‎board next to the headers should remain empty.‎

attach_36

Attach the Feather nRF52840 to the mounting bracket using three ‎M2.5 screws.‎

feather_37

Plug the rotary encoder into the Feather nRF52840's headers. The ‎rotary encoder breakout board's mounting holes should line-up with ‎the mounting bracket's mounting holes.‎

plug_38

Case Lid

Attach the case's lid to the mounting bracket with four M2.5 screws. ‎The screws will go through the mounting holes on the lid, rotary ‎encoder breakout board and the mounting bracket.‎

bracket_39

Secure the lid to the mounting bracket with four M2.5 nuts.‎

secure_40

Case Body

Plug a LiPo battery into the Feather nRF52840.‎

plug_41

Insert the mode switch into the cut-out on the side of the case.‎

insert_42

insert_43

Insert the on/off switch into the cut-out on the bottom of the case.‎

bottom_44

bottom_45

Close the case with the lid and you're ready to use your new BLE ‎remote!‎

remote_46

Usage

complete_47

After powering up the remote and connecting it to your computer via ‎BLE, open your favorite streaming app (Netflix, YouTube, etc.). You'll ‎be able to control the following parameters:‎

Full screen: Up Button
Skip ahead: Right Button
Rewind: Left Button
Mute audio: Down Button
Increase volume: Scroll forward
Decrease volume: Scroll backward
Play/pause: Center button

To switch to Doom mode, flip the switch on the side of the controller. ‎You can access classic Doom on the Internet Archive.‎

mode_48