We’ve already covered Realtek Ameba ARM Cortex M3 WiSoC several times with their RTL8710AF, RTL8711AM and RT8195AM solutions, but the company has now a new “Ameba Z series” relying on an ARM Cortex M4 core starting with RTL8711BN MCU.
RTL8710BN specifications as listed on Realtek website:
- CPU – ARM Cortex-M4(F) up to 125MHz with FPU (TBC)
- Memory – 256KB embedded SRAM
- Storage – 512KB embedded ROM, external flash interface; XIP (eXecut In Place) support
- 2.4GHz 1T1R 802.11b/g/n up to 150Mbps; 20MHz and 40MHz
- WEP, WPA, WPA2, WPS support
- Security engine – MD5, SHA-1, SHA2-256, DES, 3DES, AES
- Peripheral Interfaces
- SDIO Slave
- 2x UART
- SPI interface (Master/Slave)
- 2x I2C interface
- ADC for voltage management
- 5x PWM
- Up to 17x GPIOs
- Package – QFN-32; 5 x 5 mm
AFAIK, other Ameba MCUs do not support XIP, but RTL8710BN and this lowers memory requirements since code can be executed from storage.
MJIOT-AMB-03 module – pictured at the top of this post – is the first module based on RTL8710BN, supports up to 128 MB external flash, and includes a PCB antenna, and an u.FL connector. Power consumption is said to be 2.5 mA during operation, and 70 uA during sleep (@ 3.3V?). The module can be made to interface with cloud services such as Ailink, Joylink, QQlink, Hilink, Gagent, and Weichat. You can find a longer list of hardware parameters here.
The module can also be found on MJIOT-AMB-03-DEBUG, a breadboard-friendly board with a micro USB port, two buttons, and a JTAG/SWD header. The module used to be sold for $1.98 and the board for $5 on eBay, but the listings have expired. However, some RTL8710BN items are still for sale on Taobao with a 5 CNY ($0.725) adapter board for MJIOT-AMB-03 module, 13.30 CNY ($1.93) for the module itself, and 30 CNY ($4.35) for the development board. Shipping (to China) adds 8 CNY ($1.15).
However, you can’t do much with an SDK, and kisste, who has been deeply involved in Ameba solutions (see VGA on RTL8710), found out that this module requires a newer Ameba SDK, and that Ameba SDK 4.0A without NDA had just been released with support for RTL8710BN / Ameba Z series MCU and mbedTLS.