Pysense external wakeup pin (P9) is pulled low when in deepsleep
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Re: Pysense pinout / wake on pin
I have just confirmed the bug discovered in the last comments in the above post using the latest firmware for Pysense (0.0.8) and SiPy (1.17.0.b1). The problem is P9 is pulled low when py.go_to_sleep() is executed meaning that it fights any external signal trying to raise the P9 pin to cause a wake. This is particularly bad when the external wake source is weak (it will struggle to raise the pin) or normally high when not outputting a wake signal (excessive power dissipation during sleep). As mentioned above, a compromise is to cut that pin off the SiPy (or, less drastically, use standoffs between the Pysense and SiPy and cut that pin off the standoff) and use "peek" to see the pin level if required and put up with not being able to use callbacks. Has this bug been fixed?
It would be good if Pycom could comment on the general suitability of using P9 as a wake interrupt anyway, given that it is one of the strapping pins which should usually be left alone at startup.
On a related note, P9 only reacts to rising OR falling edges. Will it in future support rising AND falling edges like general pin interrupts do?