I’ve just been notified about an inexpensive board (HLK-W806) based on WinnerMicro W806 32-bit XT804 (XuanTie E804) microcontroller clocked at up to 240 MHz and equipped with 1MB flash and 288KB RAM.
XuanTie is the microcontroller family from Alibaba’s subsidiary T-Head Semiconductor, notably XuanTie RISC-V cores, but I’ve just learned not all XuanTie cores are based on the RISC-V architecture, and as we’ll see below, Xuantie E804 core appears to be based on the C-Sky architecture. It may still be interesting, as it’s in the STM32 board price range (pre-2020), but with a much higher frequency, so let’s have a look.
- MCU – WinnerMicro W806 32-bit XT804 microcontroller @ 240 MHz with 1MB Flash, 288KB RAM, FPU, DSP, crtypto engine
- Expansion – 2x 24-pin headers with (based on MCU specs)
- 1x SDIO host with support for SDIO 2.0, SDHC, MMC 4.2
- 1x SDIO device up to 200 Mbps
- Up to 6x UART, 1x I2C
- 1x SPI slave up to 50 MHz, 1x master/slave SPI
- LCD controller with support for 4×32 interface
- 1x I2S
- Up to 4x ADC (16-bit, 1KHz sampling rate)
- Up to 44x GPIOs, 5x PWM
- Up to 15 touch sensors
- ISO/IEC 7816 smart card interface
- Reset, Wakeup, 3.3V, and GND signals
- Debugging – CH340 via micro USB port
- Misc – Reset and Boot buttons
- Power Supply – 5V via micro USB port
- Dimensions – 65 x 26 mm (Almost the same size as a Raspberry Pi Zero, but not quite as wide)
The WinnerMicro W804 comes in a QFN56 (5×5) package, and in the specifications above, I assumed all interfaces were made available via the 48-pin headers. What was harder to find is documentation… The first page presented to me after a web search asked me to join QQ group 739265828, which I did not feel like doing, and it appears there’s a trend to make development tools hard and cumbersome to use…
But eventually, I came across a Reddit thread about this very board, where I learned that XuanTie E804 is C-Sky ISA, not RISC-V, and got a link to some useful documentation with notably W806 datasheet and even one SDK with libraries and C programs for each peripheral. Somehow the company promotes W806 as an “IoT” microcontroller despite having no wireless or wired communication interfaces.
HKL-W806 board can be purchased for a little over $2 on Aliexpress, where you’ll also find the MCU for $1.59. The price in China is lower with the board going for under 8.9 RMB ($1.4) and the chip for 5.93 RMB (93 cents) on Taobao.
Thanks to Freire for the tip.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.