# Hardware

Current target: **PineTime smartwatch**.

PineTime is an open hardware smartwatch designed by Pine64.

It is capable of running fully custom firmware.


## Core Specifications

Main hardware components include:

- Nordic **nRF52832** MCU (ARM Cortex-M4F)
- 64 KB RAM
- 512 KB internal flash
- additional **4 MB SPI NOR flash** for assets
- Bluetooth Low Energy support

The CPU runs at **64 MHz** and includes a floating-point unit.

## Display

PineTime includes:

- 1.3 inch IPS display
- resolution **240×240**
- **ST7789 display controller**
- capacitive touchscreen controller

The display is connected through SPI.

## Sensors

The device contains several sensors and peripherals:

- BMA421 accelerometer
- HRS3300 heart rate sensor
- vibration motor
- capacitive touchscreen

These are typically connected over I²C.


## Battery

PineTime uses a small Li-Po battery around **170-180 mAh** capacity.

Battery life depends heavily on firmware design and BLE usage.


## Development Constraints

Important constraints for firmware design:

- very limited RAM (64 KB)
- limited internal flash (512 KB)
- firmware must run entirely from internal flash
- external flash cannot execute code

The external flash is mainly used for:

- fonts
- assets
- large UI resources.


## Future Hardware Support

Vaka OS is designed primarily for PineTime.

Portability may be considered later but is **not a primary goal** during early development.