Raspberry Pi have just released a little box which can be used to debug programs on their Pico microcontroller; for example to load code into the device, set breakpoints and examine the state of a fledgling program.
The pack includes a set of cables which provides: a UART serial console (over the USB connection to the host), two options for a SWD (serial wire debug) connection over USB, JST connector built in to Pico H and WH, cable for the three-pin pads (which will need headers soldered on) for original Pico and Pico W.
A neat touch on the packaging is fold-up tabs picturing the options provided.
There's comprehensive documentation available at https://www.raspberrypi.com/documentation/microcontrollers/debug-probe.html including setting up the software needed to drive the probe (for different host platforms). If you want to wire it to the Pico/Pico W via the SWD pads, the wiring looks like:
To summarise, this is a very neat, well-documented tool, which is itself implemented with the RP2040 chip, a demonstration of its place as an innovative and inexpensive embedded device.