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FeatherClock 1.3.0

This repo contains code written for the Adafruit Feather HUZZAH ESP32 and the Raspberry Pi Pico W, all running MicroPython.

It is an attempt to replicate my Electric Imp clock project. It uses the Adafruit FeatherWing four-digit, seven-segment LED add-on, or any other HT16K33-based segment LED for that matter.

Currently, the clock has no remote control, which the Electric Imp Platform makes very easy to implement, but is rather less so here. You can set preferences, though. Adding a web UI, served locally or remotely, lies in a future phase of the project.

Note I previously supported the Adafruit Feather HUZZAH ESP8266, but this is no longer the case: its RTC is poor and it has too little memory. If you are using this board, you can find the code in the archive directory. I will instead be focusing on boards that are more modern.



For ESP32 boards

  1. Install from GitHub.
  2. Install using brew install esptool

For Pico W boards

  1. Install from GitHub.
  2. Download MicroPython and drop the .uf2 file onto the mounted RP2 drive.

App Installation

For ESP32 boards

  1. Connect your assembled FeatherClock (Feather plus LED add-on).
  2. Run ls /dev/cu*
    1. Note the Feather’s device file path.
  3. Update MicroPython:
    • For ESP32:
      1. --chip esp32 --port <FEATHER_DEVICE_PATH> erase_flash
      2. --chip esp32 --port <FEATHER_DEVICE_PATH> --baud 460800 write_flash -z 0x1000 esp32-20220618-v1.19.1.bin
  4. cd featherclock
  6. Press 3 for an ESP32 device.
  7. Enter your WiFi SSID.
  8. Enter your WiFi password.
  9. After the code has copied, power-cycle your FeatherClock or press the RESET button.

For Pico W boards

  1. Connect your assembled FeatherClock (Pico W plus HT16K33-based LED).
  2. ls /dev/cu*
    1. Note the Pico’s device file path.
  3. cd featherclock
  5. Press W for a Pico W.
  6. Enter your WiFi SSID.
  7. Enter your WiFi password.
  8. After the code has copied, power-cycle your FeatherClock.

Clock Settings

For now, the clock’s prefs are set by sending over a prefs.json file with the following values:

{ "mode":   <true/false>,   # 24-hour (true) or 12-hour (false)
  "colon":  <true/false>,   # Show a colon between the hours and minutes readouts
  "flash":  <true/false>,   # Flash the colon symbol, if it's shown
  "bright": 10,             # Display brightness from 1 (dim) to 15 (bright)
  "bst":    <true/false>,   # Auto-adjust for Daylight Saving Time
  "do_log": <true/false> }  # Write log data to the file `log.txt` on the device

Having installed as above, you send over prefs file using: -d <FEATHER_DEVICE_PATH> -f cp prefs.json :prefs.json

However, the script does this for you, and allows you to enter your WiFi credentials

To get <FEATHER_DEVICE_PATH>, you can add my Z Shell function dlist() to your .zshrc file. After restarting your terminal, you can run:

./ $(dlist)

To Do

  • Web UI for clock settings control.

Release History

  • 1.3.0 24 January 2023
    • Add experimental Trinkey RP2040 version.
    • Better resilience to WiFi connection loss.
    • Better log file management.
    • Update to latest HT16K33 drivers.
    • Archive ESP8266 version.
  • 1.2.3 23 February 2022
    • Better help in
    • Device-side errors now issued to log file.
    • Correct pyboard instructions.
  • 1.2.2 5 February 2022
    • Style install script errors.
    • Update installation instructions.
    • Add dlist() link.
    • No application code changes.
  • 1.2.1 13 September 2021
    • Clarify installation instructions for ESP32 and ESP8266 boards.
    • Update install script.
    • No application code changes.
  • 1.2.0 26 August 2021
    • Fix for post time-check pauses
    • Update to use MicroPython’s
    • Update to copy prefs.json over if it is present in the working directory.
  • 1.1.0 3 December 2020
    • Revised code.
    • Matrix display version.
  • 1.0.10 19 November 2020
    • Adds Feather Huzzah 32 version.
  • 1.0.9 29 September 2020
    • Improve RTC time checks.
    • Improve installation script.
  • 1.0.8 6 September 2019
    • Add installation script.
  • 1.0.7 25 April 2019
    • Add optional on-device JSON prefs (prefs.json) loading.
  • 1.0.6 13 April 2019
    • Add app preferences structure.
  • 1.0.5 10 April 2019
    • Correct the months used for BST checking.
  • 1.0.4 9 April 2019
    • Various linting-suggested code improvements.
  • 1.0.3 8 April 2019
    • Improve RTC updates by making NTP checks.
  • 1.0.2 — 5 April 2019
    • Add regular RTC updates.
  • 1.0.1 4 April 2019
    • Add disconnection indicator to display.
    • Correct constant usage.
  • 1.0.0 3 April 2019
    • Initial release.


FeatherClock is copyright 2023, Tony Smith. It is released under the MIT licence.