The Black Magic Probe by Black Sphere is an in-application debugging tool for embedded microprocessors. I like that it implements the GDB extended remote debugging protocol, so there's no need to run OpenOCD on the host computer. Over one connection it will appear as a USB serial port hosting the GDB server and a second USB serial port, which connects to the hardware UART on the target device. Similar to what @STMDude showed me, but without needing a USB hub IC and an TTL IC.
Normally I use an ST-Link v2 and a generic USB-TTL adapter. It would be really nice to have only a single, small device.
I haven't played with it yet, but I dropped the layout into a PCB order I made recently. I'll see about getting it working next week when I get the PCBs. Before then I'll try loading the firmware on an ST-Link v2 or STM development board I have.
If the black magic probe works well, I'd like to make a super tiny version. The Black Magic Probe uses an STM32F103CB, which is a 64 pin LQFP package. The STM32F103TB (datasheet) is a 36 pin DFN package and is quite a bit smaller. Looking at the blackmagic schematic and source code leads me to believe the firmware can be ported to the 36 pin chip.
Here is the Black Magid Probe Mini schematic.
Here is the board layout. I added the QFN36 footprint above the PCB to show the size difference.
- What are the options for the serial port connection? A regular 0.1" header? Maybe a smaller pin pitch? Is there anything close to a standard out there?
- MiniUSB, MicroUSB, or USB-C? I'm leaning toward USB-C to match everything else I carry around.