Arduino Watch: Crafting a smart timepiece with endless possibilities

Contents hide

1 Summary of Arduino Watch

2 Step 1: Preparation

3 Step 2: Fixing Dev Board & LCD

4 Step 3: Connect GND

5 Step 4: Connect Power Pins

6 Step 5: Connect LCD Pins

7 Step 6: Remove Power Led

Summary of Arduino Watch

This Instructables guides you through making an Arduino Watch using the Arduino Watch Core. It involves assembling a Sparkfun Pro Micro 3.3V 8 MHz dev board with a ST7789 1.3" IPS LCD, powered by a 301420 LiPo battery and charged via a compact LiPo charge board. The watch uses a DS3231M RTC chip for timekeeping and optionally a small RTC battery for backup. Key steps include fixing the dev board and LCD together, connecting ground and power lines with copper foil tape, wiring the LCD pins to Arduino GPIOs, and removing the power LED to save power.

Parts used in the Arduino Watch:

Sparkfun Pro Micro 3.3V 8 MHz dev board
ST7789 1.3" IPS LCD
301420 LiPo battery
15 mm x 15 mm LiPo charge board
DS3231M RTC chip
MS412FE RTC backup battery (optional)
20 mm width fabric canvas watch strap
Diode (e.g., 1N5822)
Four 6 mm M2 screws
Copper foil tape
Wires
Small piece of PET plate

This Instructables show how to make a Arduino Watch from Arduino Watch Core.

Step 1: Preparation

Arduino Dev Board

This time I am using Sparkfun Pro Micro 3.3 V 8 MHz dev board.

Watch Display

This time I am using a ST7789 1.3″ IPS LCD.

Lipo Battery

I have some 301420 Lipo battery in hand.

Lipo Charge Board

I have some 15 mm x 15 mm Lipo charge board in hand.

RTC Chip

This time I am using DS3231M, it built-in crystal oscillator, no extra component required

RTC Battery

This is optional, in case you want to keep the time even Lipo battery used up. MS412FE is a tiny 1 mAh rechargeable battery, according to the RTC datasheet 1 mAh already can keep time many days.

Watch Strap

I have ordered some 20 mm width fabric canvas watch strap.

Others

A diode e.g. 1N5822, four 6 mm M2 screws, copper foil tape and some wires

Step 2: Fixing Dev Board & LCD

Use a small piece of PET plate to stick the Pro Micro and IPS LCD together.

Step 3: Connect GND

Read the LCD datasheet provided by your vendor.

Cut a little copper foil tape just touch all GND pins and LED negative pins and fix it on the FPC plate. Then soldering the pins with copper foil tape.

Step 4: Connect Power Pins

Connect dev board GND Pins to the copper foil tape. Connect Vcc pins to LCD Vcc pin.

Step 5: Connect LCD Pins

Here are the connection summary:

LCD  -> Arduino
LED+ -> GPIO 10
SDA  -> GPIO 16(MOSI)
SCL  -> GPIO 15(SCLK)
RST  -> GPIO 18(A0)
DC   -> GPIO 19(A1)
CS   -> GPIO 20(A2)

Step 6: Remove Power Led

The power LED always on and consume over 1 mA continuously, so it is better remove it. Unsoldering and remove the LED carefully.

Arduino Watch