A project log for Open Source Transparent Watch - T1

A open source transparent watch, ultra-thin, BLE, 20mm strap

ModularModular 07/25/2021 at 15:200 Comments

These days I draw a schematic based on BL702, there may still be some problems, but the basic framework has been determined, in the process of drawing PCB may also make some adjustments, the current version is for reference only, if you have good suggestions, please leave a message.

Here's an introduction to the chip:

BL702/BL704/BL706 (

BL702/BL704/BL706 is highly integrated BLE and Zigbee combo chipset for IoT applications.

Wireless subsystem contains 2.4G radio, BLE+Zigbee baseband and MAC designs. Microcontroller subsystem contains 32-bit RISC-V CPU, high-speed cache and memories. Power Management Unit controls ultra-low-power modes. Moreover, variety of security features are supported.

Peripheral interfaces include USB2.0, IR-remote, Ethernet, SPI, UART, ISO 17987, I2C, I2S, PWM, QDEC, KeyScan, ADC, DAC, ACOMP, PIR, etc.

Flexible GPIO configurations are supported. BL702 has 15 GPIOs, BL704 has 23 GPIOs, and BL706 has 31 GPIOs.

With the links below, you can easily configure pins, clocks, etc.

Bouffalo Lab Config Wizard