WiFi Sync Clock

Three hand analog clock with automatic time adjustment using NTP via WiFi. Intelligence of the micro controller now removes the gears from the clock.

• This clock has no gears to rotate hands although it has only one stepper motor.
• Hooks behind the hands interfere with other hands, and reciprocal rotation of the second hand controls the position of the other hands.
• Mechanical endstop defines the origin of the all hands. It has no origin sensors.
• Unique and fun motion seen every minute.

note : Two hand version without strange motion (WiFi Sync Clock 2) is published.

You need (other than 3D printed parts)

• ESP32 based micro controller with WiFi. I used "MH-ET LIVE MiniKit" type ESP32-WROOM-32 board (around 5USD).
• 28BYJ-48 geared stepper motor and its driver circuit (around 3USD)
• M2 and M3 tapping screws

• Print all parts with supplied posture.
• No support needed.
• Select either "backplate.stl" (for wall clock) or "backplate-with-foot.stl" (for desk clock)

• Remove debris and blobs from the parts well. Especially, all axes of hands should be smooth to avoid unintentional motion of hands.
• Check the friction given by the friction unit (friction1.stl and friction2.stl). If the hour or minute hands move unintentionally, increase the friction by inserting foam rubber as shown above.

• Connect the ESP32 and driver boards as shown above.

Assemble all parts by stacking each other.

• Fix the back plate to the front face(dial.stl) by using 2mm tapping screws.
• Fix the stepper motor with 3mm tapping screws. If the length of the screw is too long, please use some spacers.
• Fix the circuitry to the back of front face. Please use short 2mm tapping screws. If the ESP32 comes out from the driver board, use some tie wraps.

You can configure your WiFi to the micro controller by two ways : Smartconfing or Hard coding.

Smartconfig

You can set SSID and password of your WiFi using smartphone app.

1. Set true to the flag named WIFI_SMARTCONFIG at line #7 in the source code,

#define WIFI_SMARTCONFIG true

then compile and flash it to the micro controller.

2 Install the apps for setting WiFi. The apps are at

• Android: https://play.google.com/store/apps/details?id=com.khoazero123.iot_esptouch_demo&hl=ja&gl=US
• iOS: https://apps.apple.com/jp/app/espressif-esptouch/id1071176700

3 Power on the clock and wait for a minute. The status of WiFi connection is indicated by the motion of the second hand.

• Large reciprocal motion : connecting to WiFi using previous setting stored in non-volatile memory.
• Small reciprocal motion : SmartConfig mode. If 30 seconds of WiFi connection trial fails, it automatically moves to the the smartConfig mode (waiting for the configuration from smartphone app.)

4 Set the password of your WiFi using the app as shown above.

Please not that your smartphone should connect to 2.4GHz WiFi. Configured WiFi settings are stored in non-volatile memory and are kept even when the power is turned off.

Hard coding

Set the SSID and password of your WiFi in the source code. It is useful if you can not select 2.4GHz wifi via SSID.

1 Set false to the flag named WIFI_SMARTCONFIG at line #7 in the source code,

#define WIFI_SMARTCONFIG false

2 Then set SSID and password of your WiFi in the source code directly at lines #11-12,

#define WIFI_SSID "SSID" // your WiFi's SSID
#define WIFI_PASS "PASS" // your WiFi's password

3 Compile and flash it to the micro controller.