Deep sleep and Output pin state


I am using a Particle Photon with the Adafruit ultimate GPS. The aim is to conserve as much battery power as possible and only wakeup the Photon once a day to publish the GPS location.

I am using the Enable pin (EN) on the GPS module to shut-down the GPS (Photon IO Pin 7 set to Output and LOW) just before entering into deep sleep. The issue I have is that once the Photon has entered into deep sleep, the IO pin goes out of the LOW state and the GPS is no longer deactivated.

Any ideas on how I could solve this?



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Just a note - the GPS enable pin has a pull-up resistor attached to it making the default state GPS enabled… Removing this resistor would set the default GPS device state to disabled hence solving the issue with the Photon Deep Sleep state turning the GPS module back on, i.e. the Photon would enable the GPS by setting Pin 7 HIGH and when entering deep sleep, Pin 7 would disable the GPS.

Did removing the pull-up resistor solve your problem, or are you just proposing this as a possible solution?

Hi Ric,

I should have clarified, removing the pull-up resistor was proposed as a possible solution with a bit of a question mark behind it.

Hi Ric,

Removing the Enable pull-up resistor solved the issue, pretty clear when you think about it.

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