Avaota F1 – A tiny camera board based on Allwinner V821 RISC-V SoC with built-in WiFi and 64MB DDR2

The Avaota F1 is an ultra-small, open-source hardware Linux SBC powered by an Allwinner V821 32-bit RISC-V camera SoC with 64MB on-chip DDR2 and built-in 2.4 GHz WiFi 4, and designed for camera applications with a MIPI CSI connector.

The 35×22 mm board also features a 32MB NOR flash, an analog microphone, a USB-C port for power, data, and programming, two 15-pin GPIO headers, a FEL button, and a user LED. It looks like it will be offered as a development kit with a 1080p30 camera and a 3.5-inch or 1.54-inch SPI display. I also think it’s the first time I’ve seen a Linux-capable application processor with built-in WiFi.

Avaota F1 specifications

• SoC – Allwinner V821L2-WXX
  • CPU
    • 32-bit RISC-V CPU @ 1.2GHz with 16KB L1 D/I  cache, 128KB L2 cache
    • 32-bit RISC-V MCU @ 600 MHz with  16KB L1 I-cache, 8KB L1 D-cache
  • Memory – 64MB DDR2 on-chip
  • VPU – H.264/MPJEG decoder up to 1080p60, H.264 encoder
  • ISP – Supports dual-camera 1920×1080 @ 15fps + 640×480 @ 15fps stream processing
  • Wireless – 2.4GHz Wi-Fi with 180uA power consumption in DTIM10 mode
  • Built-in RTC
• Storage – 32MB NOR flash (PY25Q256)
• Display – SPI interface (via pin headers) for optional 3.5-inch display with 480×320 resolution or 1.54-inch display with 240×240 resolution
• Camera –  MIPI CSI connector for optional GC2083 1920×1080 @ 30fps camera
• Audio – Built-in analog microphone
• USB – 1x USB Type-C port for power, data, and serial debugging
• Expansion – 2x 15-pin headers (through and castellated holes) with up to 28x GPIO
• Debugging
  • UART serial and ADB USB debugging are supported
  • JTAG vai microSD card
• Misc
  • FEL button to flash the OS
  • LED
  • Ceramic antenna for WiFi
• Power Supply
  • 5V via USB-C port
  • PMU –  EA3036 PMIC
• Dimensions – 35 x 22mm (6-layer PCB)

The Avaota F1 runs Tina Linux 5.0 operating system developed by Allwinner. Hardware design files (PDF schematics, PCB layout, Gerber, BoM, etc…) can be found on GitHub, but I could not find an OS image for the board. This forum thread indicates Tina Linux is a fork of OpenWrt 21.02. Allwinner V821 resources with datasheet, Tina Linux SDK, and other information are available on Allwinner’s documentation website (in Chinese only).

There are three versions of the Allwinner V821 SoC:

• Allwinner V821L2-WXX (used in Avaota F1) – Serial RGB/i8080/SPI display interfaces, WiFi with low-power keep-alive, and RTC
• Allwinner V821L2-XXX – SPI display interface, no WiFi, no RTC
• Allwinner V821M2-WXX – SPI display interface, WiFi, no RTC

 

The diagram above shows that the 1.2 GHz RISC-V CPU is designed to handle features such as DRAM and storage, while the 600 MHz RISC-V MCU manages WiFi and an optional 4G LTE module. Other features like H.264 VPU, cameras, SPI, GPIO, audio, etc… are shared between the two RISC-V cores.

The Avaota F1 can be purchased on Taobao for 49.9 CNY (about $7). I could not find it in other places, but considering the Allwinner T527-powered Avaota A1 SBC is sold on Pine64, I would not be surprised to find it with other Yuzuki-branded boards on the Pine64 store. The Allwinner V821 chip looks rather interesting for low-cost WiFi/4G LTE camera applications, so I’d expect other boards or products to follow suit shortly.

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