I was curious to see how much power this setup consumes... 2 SDR radios, GPS/AHRS, and a WiFi dongle plus the Pi itself. The Pi people suggest 1 amp input, which is shared with all things connected. I seem to remember that the Pi itself needs about .3 to .7 amps itself, depending on load. All my 5v wiring is soldered in place, so I couldn't measure it there. But on the 12v input side of the buck converter, the converter was consuming about 0.63 amps of 12v juice. Specifically, the battery was at 12.3 volts. So doing the math and assuming 90% efficiency going from 12.3 to 5.15 volts, the Stratux hardware was steadily drinking the 5v juice at a rate of just under 1.5 amps while sitting on the kitchen table. Perhaps that goes up slightly in flight when the radios are actually receiving data, the Pi is processing the data, and the WiFi is sharing the data. At any rate now I know why, before switching to this setup, most all of my USB cables couldn't power the system and why some USB chargers can't handle the load, and why the red light would occasionally blink (signaling insufficient power). The buck converter I'm using now (that takes up to 50 volts input and converts it to 5.15 volts output) is rated for 3 amps output, which is shared to All devices via a USB hub. My next iteration will separate out the power even more.