Fix negative voltage when Wifi module is off

[platisd]

Description

When the WiFi module was turned off, the power controller did not have a common ground with the wifi module, which would cause the relative voltage (from the wifi module's perspective) to be negative. This would strangely result in a constant low voltage of around 1-1.5 volts being present at the VCC and GND pins of the WiFi module. This resulted in weird behavior and overall needlessly higher power consumption.

The fix involves the PB0 pin being set to INPUT so to avoid this noise on the Wifi module's side. Whenever we want to transmit a pulse through the PB0 pin, we set it as OUTPUT (then the WiFi module is ON so there is no problem) and when we are done we set it back to INPUT again.

Solved issue(s)

Fixes #65

[codecov[bot]]

Codecov Report

Merging #70 into dev will increase coverage by 0.05%. The diff coverage is 100%.

@@           Coverage Diff           @@
##           dev      #70      +/-   ##
=======================================
+ Coverage   75%   75.05%   +0.05%     
=======================================
  Files       10       10              
  Lines      464      465       +1     
=======================================
+ Hits       348      349       +1     
  Misses     116      116

Impacted Files	Coverage Δ
ins-node/src/power_controller/power_controller.ino	90% <100%> (+0.11%)	:arrow_up:

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