With help from @kattni, I chased a simpleio problem to this reproducer: ``` Adafruit CircuitPython 5.0.0-alpha.2-35-gfb1f55998-dirty on 2019-09-11; Particle Xenon with nRF52840 >>> >>> import pulseio >>> import board >>> with pulseio.PWMOut(board.A0): pass ... >>> with pulseio.PWMOut(board.A0): pass ... Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: A0 in use ```