I want to make the Smart watch.

but there are projects where I want to attach a small display for quickly figuring out the current state.

Step 1: Parts

WIZwiki-W7500
- ARM Cortex-M0
- Hardwared TCP/IP
Adafruit
- OLED 128 x 64
- I2C communication
Jumper line

Hardware parts for smart watch

WIZwiki-W7500

32-bit ARM Cortex-M0
Flash : 128KB / SRAM : 16KB (up to 48KB)
Hardwired TCP/IP Core (Supports MII Interface)
Internal 8MHz Oscillator
External crystal Oscillator (8~24MHz)
48MHz maximum frequency
PLL for internal clock source
ADC - 12bit, 8ch, 1Mbps
DMA - UART, SPI, Software
GPIO 53ea I/O
4 Timer/ 8 PWM
3 UART, 2 SPI, 2 I2C
32bit RNG
Serial Wire Debug(SWD)
Package : 64TQFP (7x7 mm)

Adafruit

Power supply
- VDD = 1.65V to 3.3V for IC logic
- VCC = 7V to 15V for Panel driving
For matrix display
- OLED driving output voltage, 15V maximum
- Segment maximum source current: 100uA
- Common maximum sink current: 15mA
- 256 step contrast brightness current control
Embedded 128 x 64 bit SRAM display buffer
Pin selectable MCU Interfaces:
- 8-bit 6800/8080-series parallel interface
- 3 /4 wire Serial Peripheral Interface
- I2C Interface

For detailed, please refer the attached file.

SSD1306-Revision 1.1 (Charge Pump).pdf
Download

Step 2: Structure

WIZWatch is a simple system that is used a hardware platform called WIZwiki-W7500. The overall structure is in the picture above.

You can regulate the time using the button.

Step 3: WIZwiki-W7500 Pinout

Step 4: Electronic Assembly

# WIZwiki-W7500 <--------------> OLED

3.3V <--------------------------> VCC
GND <--------------------------> GND
PA_09 <------------------------> SCL
PA_10 <------------------------> SDA

Battery

You can simply connect battery by connecting (+) -> RAW, GND -> GND. You need to put (+) line to RAW pin in case you use any sort of external power supply, such as an external battery.

(I will write you about the details later on.)

Button

I will write you about the details later on.