Tiny Pod - BLE Rotary Encoder for iWatch

by Ruiz Brothers and

published November 26, 2024, last updated November 26, 2024

posted in 3D Printing CircuitPython Internet of Things - IOT/ Bluefruit / BLE

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Project guide

Overview

Build a Media Controller

Turn an old Apple Watch into a mini iPod! Use BLE on a Feather ESP32 S3 with an ANO rotary encoder wheel to control the watch interface. The encoder wheel is reminiscent of the original clicking scroll wheel interface on the first iPods

This project features the ANO rotary encoder wheel. It’s got four directional buttons and a center button for scrolling and clicking. It’s essentially a wireless USB controller that pairs with an Apple Watch over BLE. It’s inspired by The Tiny Pod project we saw online, to make an open source and hackable version!

ESP32-S3 BLE with CircuitPython

Powered by the Adafruit Feather ESP32-S3, it’s got Wifi, BLE and on board battery charging, perfect for making portable IOT and BLE projects.

The ANO Rotary encoder breakout connects over STEMMA QT, making it easy to plug and play with the Adafruit Feather.

With Apple’s watchOS, you can enable the Voiceover accessibility feature to allow pairing keyboard devices over BLE. This allows you to scroll through the elements on screen and select items using the directional buttons and center click wheel.

Parts

Angled shot of rectangular microcontroller.

Adafruit ESP32-S3 Feather with STEMMA QT / Qwiic

The ESP32-S3 has arrived in Feather format - and what a great way to get started with this powerful new chip from Espressif! With dual 240 MHz cores, WiFi and BLE support, and native...

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$17.50

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ANO Directional Navigation and Scroll Wheel Rotary Encoder

This funky user interface element is reminiscent of the original clicking scroll wheel interface...

$8.95

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Overhead video of a blue-manicured finger manipulating a rotary encoder connected to a 4-digit LED segment display.

Adafruit ANO Rotary Navigation Encoder to I2C Stemma QT Adapter

The ANO rotary encoder wheel is a funky user interface element, reminiscent of the original...

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$4.95

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STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long

This 4-wire cable is 50mm / 1.9" long and fitted with JST SH female 4-pin connectors on both ends. Compared with the chunkier JST PH these are 1mm pitch instead of 2mm, but...

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Breadboard-friendly SPDT Slide Switch

These nice switches are perfect for use with breadboard and perfboard projects. They have 0.1" spacing and snap in nicely into a solderless breadboard. They're easy to switch...

$0.95

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Lithium Ion Polymer Battery - 3.7v 500mAh

Lithium-ion polymer (also known as 'lipo' or 'lipoly') batteries are thin, light, and powerful. The output ranges from 4.2V when completely charged to 3.7V. This...

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1 x 44mm Apple Watch Series 5

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6 x M2.5x5mm Screws

M2.5x5mm Screws

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2 x M2x5mm Screws

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Circuit Diagram

The diagram below provides a general visual reference for wiring of the components once you get to the Assembly page. This diagram was created using the software package Fritzing.

Adafruit Library for Fritzing

Adafruit uses the Adafruit's Fritzing parts library to create circuit diagrams for projects. You can download the library or just grab individual parts. Get the library and parts from GitHub - Adafruit Fritzing Parts.

Wired Connections

The ANO rotary encoder is soldered to the PCB with STEMMA Stemma QT Adapter
The slide switch is connected to the EN and GND pins on the Feather
The Lipo battery plugs into the Battery port

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Watch Setup

Enable Voice Over

Go to Settings and then Accessibility. Now go to the VoiceOver sub menu.

Wait to enable Voice Over until the keyboard is paired via Bluetooth.

https://support.apple.com/guide/watch/use-a-bluetooth-keyboard-apd006574536/11.0/watchos/11.0

Set the modifier key to "caps lock". The Up button on the ANO encoder is setup to start up the keyboard with caps lock key.

Setup 3 button press with the Crown button to turn VoiceOver On/Off: https://support.apple.com/guide/watch/the-accessibility-shortcut-apda74993b58/watchos

Navigation buttons

The scroll wheel scrolls either up or down, left and right arrows do the same, center button is used for double tap to select and down button reads out the characters.

Pair Keyboard

Inside the VoiceOver settings, tap on the Keyboard sub menu. Under Device, tap on the CIRCUITPY device to pair.

Disconnect Keyboard

If you need to disconnect/forget the Feather from BLE, you can hold down the center select button on the encoder while power cycle the Feather.

If you're connected to the repl you'll see "Last BLE bonding deleted, restarting.." and then the board reboots.

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Code

Once you've finished setting up your Feather ESP32-S3 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 to your computer as a zipped folder.

Download Project Bundle

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# SPDX-FileCopyrightText: 2024 Liz Clark for Adafruit Industries
#
# SPDX-License-Identifier: MIT

import time
import microcontroller
import board
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
from adafruit_seesaw import seesaw, rotaryio, digitalio

# ios modifier
mod = Keycode.CAPS_LOCK
#  keycodes
KBD_CODES = [
    [Keycode.SPACE], # center
    [mod], # up
    [Keycode.LEFT_ARROW], # left
    [Keycode.DOWN_ARROW], # down
    [Keycode.RIGHT_ARROW], # right
]

i2c = board.STEMMA_I2C()
seesaw = seesaw.Seesaw(i2c, addr=0x49)

seesaw_product = (seesaw.get_version() >> 16) & 0xFFFF
print(f"Found product {seesaw_product}")
if seesaw_product != 5740:
    print("Wrong firmware loaded?  Expected 5740")

buttons = []
button_names = ["Select", "Up", "Left", "Down", "Right"]
button_states = []

for s in range(1, 6):
    seesaw.pin_mode(s, seesaw.INPUT_PULLUP)
    pin = digitalio.DigitalIO(seesaw, s)
    pin_state = False
    buttons.append(pin)
    button_states.append(pin_state)

encoder = rotaryio.IncrementalEncoder(seesaw)
last_position = 0

if not buttons[0].value and button_states[0] is False:
    button_states[0] = True
    try:
        import _bleio
        time.sleep(2)
        _bleio.adapter.erase_bonding()
        time.sleep(2)
        print("Last BLE bonding deleted, restarting..")
        time.sleep(2)
        microcontroller.reset()
    except Exception: # pylint: disable=broad-except
        pass

#  BLE HID setup
hid = HIDService()
#  keyboard & mouse HID setup
kbd = Keyboard(hid.devices)

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

if not ble.connected:
    print("advertising")
    ble.start_advertising(advertisement, scan_response)
else:
    print("already connected")
    print(ble.connections)
time.sleep(2)

while True:
	#  check for BLE connection
    while not ble.connected:
        pass
	#  while BLE connected
    while ble.connected:
        position = encoder.position
        if position != last_position:
            #  if the encoder is turned to the right
            if position > last_position:
                kbd.send(Keycode.RIGHT_ARROW)
            #  if the encoder is turned to the left
            if position < last_position:
                kbd.send(Keycode.LEFT_ARROW)
		    #  reset encoder position
            last_position = position
            print(f"Position: {position}")
        for b in range(5):
            if not buttons[b].value and button_states[b] is False:
                button_states[b] = True
                if b != 0:
                    kbd.press(*KBD_CODES[b])
                    print(*KBD_CODES[b])
                else:
                    kbd.press(mod)
                    kbd.press(*KBD_CODES[b])
                print(f"{button_names[b]} button pressed")
            if buttons[b].value and button_states[b] is True:
                button_states[b] = False
                kbd.release_all()
                print(f"{button_names[b]} button released")
	#  if BLE disconnects, begin advertising again
    ble.start_advertising(advertisement)

# SPDX-FileCopyrightText: 2024 Liz Clark for Adafruit Industries
#
# SPDX-License-Identifier: MIT

import time
import microcontroller
import board
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
from adafruit_seesaw import seesaw, rotaryio, digitalio

# ios modifier
mod = Keycode.CAPS_LOCK
#  keycodes
KBD_CODES = [
    [Keycode.SPACE], # center
    [mod], # up
    [Keycode.LEFT_ARROW], # left
    [Keycode.DOWN_ARROW], # down
    [Keycode.RIGHT_ARROW], # right
]

i2c = board.STEMMA_I2C()
seesaw = seesaw.Seesaw(i2c, addr=0x49)

seesaw_product = (seesaw.get_version() >> 16) & 0xFFFF
print(f"Found product {seesaw_product}")
if seesaw_product != 5740:
    print("Wrong firmware loaded?  Expected 5740")

buttons = []
button_names = ["Select", "Up", "Left", "Down", "Right"]
button_states = []

for s in range(1, 6):
    seesaw.pin_mode(s, seesaw.INPUT_PULLUP)
    pin = digitalio.DigitalIO(seesaw, s)
    pin_state = False
    buttons.append(pin)
    button_states.append(pin_state)

encoder = rotaryio.IncrementalEncoder(seesaw)
last_position = 0

if not buttons[0].value and button_states[0] is False:
    button_states[0] = True
    try:
        import _bleio
        time.sleep(2)
        _bleio.adapter.erase_bonding()
        time.sleep(2)
        print("Last BLE bonding deleted, restarting..")
        time.sleep(2)
        microcontroller.reset()
    except Exception: # pylint: disable=broad-except
        pass

#  BLE HID setup
hid = HIDService()
#  keyboard & mouse HID setup
kbd = Keyboard(hid.devices)

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

if not ble.connected:
    print("advertising")
    ble.start_advertising(advertisement, scan_response)
else:
    print("already connected")
    print(ble.connections)
time.sleep(2)

while True:
	#  check for BLE connection
    while not ble.connected:
        pass
	#  while BLE connected
    while ble.connected:
        position = encoder.position
        if position != last_position:
            #  if the encoder is turned to the right
            if position > last_position:
                kbd.send(Keycode.RIGHT_ARROW)
            #  if the encoder is turned to the left
            if position < last_position:
                kbd.send(Keycode.LEFT_ARROW)
		    #  reset encoder position
            last_position = position
            print(f"Position: {position}")
        for b in range(5):
            if not buttons[b].value and button_states[b] is False:
                button_states[b] = True
                if b != 0:
                    kbd.press(*KBD_CODES[b])
                    print(*KBD_CODES[b])
                else:
                    kbd.press(mod)
                    kbd.press(*KBD_CODES[b])
                print(f"{button_names[b]} button pressed")
            if buttons[b].value and button_states[b] is True:
                button_states[b] = False
                kbd.release_all()
                print(f"{button_names[b]} button released")
	#  if BLE disconnects, begin advertising again
    ble.start_advertising(advertisement)

Upload the Code and Libraries to the Feather ESP32-S3

After downloading the Project Bundle, plug your Feather ESP32-S3 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 ESP32-S3's CIRCUITPY drive.

lib folder
code.py

Your Feather ESP32-S3 CIRCUITPY drive should look like this after copying the lib folder and the code.py file.

How the CircuitPython Code Works

At the top of the code are user modifiable keycodes. The defaults match the documented keycodes in the Apple Watch documentation. The code uses the caps lock key as the modifier key.

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# ios modifier
mod = Keycode.CAPS_LOCK
#  keycodes
KBD_CODES = [
    [Keycode.SPACE], # center
    [mod], # up
    [Keycode.LEFT_ARROW], # left
    [Keycode.DOWN_ARROW], # down
    [Keycode.RIGHT_ARROW], # right
]

# ios modifier
mod = Keycode.CAPS_LOCK
#  keycodes
KBD_CODES = [
    [Keycode.SPACE], # center
    [mod], # up
    [Keycode.LEFT_ARROW], # left
    [Keycode.DOWN_ARROW], # down
    [Keycode.RIGHT_ARROW], # right
]

I2C

The seesaw ANO rotary encoder is instantiated over I2C.

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i2c = board.STEMMA_I2C()
seesaw = seesaw.Seesaw(i2c, addr=0x49)

seesaw_product = (seesaw.get_version() >> 16) & 0xFFFF
print(f"Found product {seesaw_product}")
if seesaw_product != 5740:
    print("Wrong firmware loaded?  Expected 5740")

buttons = []
button_names = ["Select", "Up", "Left", "Down", "Right"]
button_states = []

for s in range(1, 6):
    seesaw.pin_mode(s, seesaw.INPUT_PULLUP)
    pin = digitalio.DigitalIO(seesaw, s)
    pin_state = False
    buttons.append(pin)
    button_states.append(pin_state)

encoder = rotaryio.IncrementalEncoder(seesaw)
last_position = 0

i2c = board.STEMMA_I2C()
seesaw = seesaw.Seesaw(i2c, addr=0x49)

seesaw_product = (seesaw.get_version() >> 16) & 0xFFFF
print(f"Found product {seesaw_product}")
if seesaw_product != 5740:
    print("Wrong firmware loaded?  Expected 5740")

buttons = []
button_names = ["Select", "Up", "Left", "Down", "Right"]
button_states = []

for s in range(1, 6):
    seesaw.pin_mode(s, seesaw.INPUT_PULLUP)
    pin = digitalio.DigitalIO(seesaw, s)
    pin_state = False
    buttons.append(pin)
    button_states.append(pin_state)

encoder = rotaryio.IncrementalEncoder(seesaw)
last_position = 0

Erase Bonding

If you find you need to forget BLE pairing on the Feather, you can hold down the center button the encoder and reboot the board. If the board detects that that button is being held down before the loop, it will delete all BLE bonding and reset.

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if not buttons[0].value and button_states[0] is False:
    button_states[0] = True
    try:
        import _bleio
        time.sleep(2)
        _bleio.adapter.erase_bonding()
        time.sleep(2)
        print("Last BLE bonding deleted, restarting..")
        time.sleep(2)
        microcontroller.reset()
    except Exception: # pylint: disable=broad-except
        pass

if not buttons[0].value and button_states[0] is False:
    button_states[0] = True
    try:
        import _bleio
        time.sleep(2)
        _bleio.adapter.erase_bonding()
        time.sleep(2)
        print("Last BLE bonding deleted, restarting..")
        time.sleep(2)
        microcontroller.reset()
    except Exception: # pylint: disable=broad-except
        pass

Start BLE

The BLE HID services are established and the BLE connection is advertised.

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#  BLE HID setup
hid = HIDService()
#  keyboard & mouse HID setup
kbd = Keyboard(hid.devices)

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

if not ble.connected:
    print("advertising")
    ble.start_advertising(advertisement, scan_response)
else:
    print("already connected")
    print(ble.connections)
time.sleep(2)

#  BLE HID setup
hid = HIDService()
#  keyboard & mouse HID setup
kbd = Keyboard(hid.devices)

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

if not ble.connected:
    print("advertising")
    ble.start_advertising(advertisement, scan_response)
else:
    print("already connected")
    print(ble.connections)
time.sleep(2)

The Loop

In the loop, the encoder sends the right arrow command when turned to the right and sends the left arrow command when turned to the left. The up, down, left, right and center buttons send the keycodes listed in the KBD_CODES array.

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while True:
	#  check for BLE connection
    while not ble.connected:
        pass
	#  while BLE connected
    while ble.connected:
        position = encoder.position
        if position != last_position:
            #  if the encoder is turned to the right
            if position > last_position:
                kbd.send(Keycode.RIGHT_ARROW)
            #  if the encoder is turned to the left
            if position < last_position:
                kbd.send(Keycode.LEFT_ARROW)
		    #  reset encoder position
            last_position = position
            print(f"Position: {position}")
        for b in range(5):
            if not buttons[b].value and button_states[b] is False:
                button_states[b] = True
                if b != 0:
                    kbd.press(*KBD_CODES[b])
                    print(*KBD_CODES[b])
                else:
                    kbd.press(mod)
                    kbd.press(*KBD_CODES[b])
                print(f"{button_names[b]} button pressed")
            if buttons[b].value and button_states[b] is True:
                button_states[b] = False
                kbd.release_all()
                print(f"{button_names[b]} button released")
	#  if BLE disconnects, begin advertising again
    ble.start_advertising(advertisement)

while True:
	#  check for BLE connection
    while not ble.connected:
        pass
	#  while BLE connected
    while ble.connected:
        position = encoder.position
        if position != last_position:
            #  if the encoder is turned to the right
            if position > last_position:
                kbd.send(Keycode.RIGHT_ARROW)
            #  if the encoder is turned to the left
            if position < last_position:
                kbd.send(Keycode.LEFT_ARROW)
		    #  reset encoder position
            last_position = position
            print(f"Position: {position}")
        for b in range(5):
            if not buttons[b].value and button_states[b] is False:
                button_states[b] = True
                if b != 0:
                    kbd.press(*KBD_CODES[b])
                    print(*KBD_CODES[b])
                else:
                    kbd.press(mod)
                    kbd.press(*KBD_CODES[b])
                print(f"{button_names[b]} button pressed")
            if buttons[b].value and button_states[b] is True:
                button_states[b] = False
                kbd.release_all()
                print(f"{button_names[b]} button released")
	#  if BLE disconnects, begin advertising again
    ble.start_advertising(advertisement)

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