Allwinner V3s Single Board Computer

Project Status

Status: Ongoing - Not Assembled Yet

Main Specifications

Processor

Allwinner V3s System-on-Chip

ARM Cortex-A7 single-core processor up to 1.2GHz
64MB integrated DDR2 DRAM
H.264 1080p@60fps video decoding
RGB LCD interface and parallel CSI camera interface
LQFP-128 package (14x14mm, 0.4mm pitch)
Multiple peripherals: SPI, I2C, UART, USB OTG, SD/MMC
Operating voltage: 3.3V I/O, multiple internal voltage domains

Video Output

Silicon Image SII9022A HDMI Transmitter

Converts parallel RGB video to HDMI/DVI output
Supports resolutions up to 1080p
Integrated HDCP encryption engine
QFN-72 package (10x10mm, 0.5mm pitch)
I2C control interface for configuration
Embedded audio support (I2S input)
Connects V3s RGB output to standard HDMI connector

Wireless Connectivity

Realtek RTL8723BS WiFi/Bluetooth Module

802.11 b/g/n WiFi (2.4GHz only)
Bluetooth 4.0 with BLE support
Integrated PA, LNA, and T/R switch
SDIO interface for WiFi, UART for Bluetooth
On-board 2.4GHz MIFA (Meandered Inverted-F Antenna)
Low power consumption optimized for battery applications
Single-chip solution reduces BOM cost

I/O Expansion

Microchip MCP23017 I2C GPIO Expander

16 additional GPIO pins via I2C interface
Each pin individually configurable as input or output
Internal pull-up resistors (100kΩ)
Interrupt output pins for input change notification
SOIC-28W package
Allows expansion beyond V3s native GPIO count
Useful for controlling additional peripherals or reading sensors

Audio System

Audio Codec and Interfaces

V3s integrated audio codec with DAC and ADC
3.5mm TRRS audio jack (PJ-320D-A) for headphone output and line-in
On-board 6mm electret microphone for audio capture
Stereo audio output capability
Mono microphone input with bias
Audio routed through HDMI transmitter for digital audio output
Analog filtering and decoupling for clean audio signals

USB and Power

2x USB Type-C ports (USB4105GFA120 connectors)
CH224K USB Power Delivery controller for negotiating 5V-20V input
TPD4E05U06DQA ESD protection on USB data lines

Expansion Header

40-pin GPIO header (2x20, 2.54mm pitch)
Exposes UART, SPI, I2C, GPIO, and power rails
NOT Raspberry Pi compatible (different pinout)

Storage & Memory

MicroSD card slot (ST-TF-003A) for bootloader, Linux OS, and filesystem
24LC512 I2C EEPROM (64KB) for board-specific persistent data

Boot and Operating System

The board boots from the microSD card, which contains the bootloader (U-Boot), Linux kernel, and root filesystem. The Allwinner V3s supports booting directly from SD card, making it easy to update or swap between different OS images.

Non-Volatile Configuration Storage

An external I2C EEPROM is included for non-volatile storage of board-specific data that should persist independently of the SD card.

Network configuration and Wi-Fi credentials
Device identifiers or serial numbers
Calibration data
User or application-defined persistent settings

Power Management

USB Power Delivery: CH224K PD controller
Dual DC-DC converters: 2x PAM2306AYPAA step-down regulators
Multiple voltage rails with extensive filtering
2A fuse protection

Debug Interface

3-pin UART header for serial console access
Multiple ESD protection circuits on external interfaces

Clock & Timing

24MHz main crystal oscillator
32.768kHz RTC crystal

Component Summary

Features

Compact SBC design based on Allwinner V3s
Integrated WiFi and Bluetooth connectivity
USB Type-C with Power Delivery support
HDMI video output
Audio input and output
Expandable via 40-pin GPIO header
MicroSD boot support
Suitable for embedded Linux applications

Design Details

This board features a comprehensive power management system with dual switching regulators and extensive decoupling (45x 100nF + 12x 10µF capacitors). The design includes proper ESD protection on USB and other external interfaces, EMI filtering, and dedicated power planes for analog and digital sections.