The BDK FreeRTOS supports multiple Beken chips, including BK7231N, BK7231U, BK7251. This repo mainly use BK7231U USB devices.

We use BK7231U 48pin chip that supports USB Host/Device, and SCH and PCB are located in Hardware directory.

Pin assignment:

Download arm gcc toolchain from https://developer.arm.com/downloads/-/gnu-rm, and set env FREERTOS_EXEC_PATH, for example

export FREERTOS_EXEC_PATH=/opt/toolchain/gcc-arm-none-eabi-5_4-2016q3/bin/

Current bash and zsh shell is supported, you may change you /bin/sh to bash or zsh.

Download source code and compile

git clone https://github.com/tiancj/bdk_freertos
make bk7231u -j$(nproc)

The generated binary is out/beken7231_bsp_crc.bin and out/all_2M.1220.bin. The former bin doesn't contain bootloader, while the latter contains bootloader.

Download Flash tool from https://github.com/tiancj/hid_download_py, and follow the instruction there to install it.

If BK7231U is a blank chip, you need to flash it a bootloader or a bin that contains bootloader.

Connect SPI flasher to BK7231U, and run the following command:

hidprogram out/all_2M.1220.bin

After flash the bootloader, you doesn't need the SPI flasher to flash bootloader later. Instead, you can use UART to flash.

uartprogram out/beken7231_bsp_crc.bin

Default baudrate is 115200 8N1, and console log is at UART1.

Then enjoy!

git checkout bootloader  # change to bootloader branch
make clean
make bk7231u -j8

uf2 bootloader is out/beken7231u_crc.bin，use hidprogram to flash.

After uf2 bootloader is flashed, press USER button before plug USB or press CEN button. Then copy uf2 firmware to usb disk, uf2 bootloader will reboot after write firmware to flash automatically.

• WiFi (use sta command to connect to AP, or softap command to setup a hotspot)
• USB Device (CherryUSB and Mentor USB), such as HID, MSC, CDC, etc.
• UF2 bootloader (enable CFG_UF2 in app/sys_config_bk7231u.h)

• USB SPI, I2C, PWM, SD/SDIO, ADC, IrDA, MJPEG, etc devices
• Linux device drivers for these USB device
• opensource wifi 4 protocol stack (softmac)

v There are original Beken documents at documents directory, which includes SDK API and User Guide. SDK API is recommended to read to familiar with API that used to develope user applications. If you want to develop USB devices or Host devices, please refer CherryUSB APIs at https://cherryusb.readthedocs.io/.

Thanks the following repos:

• cherryuf2: https://github.com/zhaqian12/Cherryuf2
• platform_bk7231t: https://github.com/warewolf/platform_bk7231t
• OpenBK7231T: https://github.com/openshwprojects/OpenBK7231T
• CherryUSB: https://github.com/cherry-embedded/CherryUSB