DroneCode Probe development board by Zubax
Zubax DroneCode Probe is a generic JTAG, SWD and UART console adapter compatible with most ARM Cortex based designs and in particular with hardware maintained by the DroneCode project.

http://docs.zubax.com/DroneCode_Probe

• micro controller: STM32F103CBT6
• USB: micro USB connector
• size: 22x44mm
• order code: 38169