The M10 board uses AP3429A as the switching regulator to convert 5 V input to 3.3 V. And the 5 V rail can come from the DC, which is converted from 9 V to 5 V by an AZ1117IH (LDO).
The AZ1117IH has a current limit of 1 A, while the AP3429A has a current limit of 2 A. In other words, the M10 board can produce a lot of juice even on its 3.3 V rail.
To visually verify that, incandescent bulbs are used as power indicator. Two types of incandescent bulbs are used here:
How is it going? Seeing is believing:
Notes: In this test, the bulb is connected between the ground and the IOREF, while the IOREF is set to 3.3 V by jumper.
An easy-to-use, micro ePaper shield for the Particle & Arduino community
A small, portable, USB-connected electronics lab-on-a-board that includes an oscilloscope, waveform generator, power supply, logic analyzer, and multimeter.
An open source, Arduino-compatible RF signal generator with Wi-Fi connectivity