Place and solder the SWD JTAG connector (2.5 1.27mm).
Solder the 2-pin JST connector.
Solder the short feather male headers. Short side up with the black plastic on the bottom. The only pins that need to be soldered are the ones with traces running to them (pins 2 and 4). I recommend at least soldering the end pins on each side to secure the headers.
Mount the JTAG debug featherwing to your Feather M0 module.
Go ahead and solder the JST pigtail connector to the bottom of your Feather M0 module. If you wish to run the leads through the Feather and FeatherWing mount holes that might make the wires look a little neater.
- JST red lead SWCLK
- JST black lead SWDIO
Plug in 2-pin JST connector to JTAG FeatherWing.