Hold GC1109 PA_POWER during deep sleep for LNA RX wake#27
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…gative claims number.
…rect-Release-of-RefCountedDigitalPin Fixed RefCountedDigitalPin.h and SSD1306Display for Heltec v4
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The GC1109 FEM needs its VFEM_Ctrl pin held HIGH during deep sleep to keep the LNA active, enabling proper RX sensitivity for wake-on-packet. Without this, the LNA is unpowered during sleep and RX wake sensitivity is degraded by ~17dB. Release RTC holds in begin() after configuring GPIO registers (not before) to ensure glitch-free pin transitions on wake. Trade-off: ~6.5mA additional sleep current for significantly improved wake-on-packet range.
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Summary
Without this, the GC1109 LNA could be unpowered during sleep, degrading RX wake sensitivity by ~17dB.
Trade-off: ~1.2mA additional deep sleep current (measured: 11.1mA → 12.3mA) for significantly improved wake-on-packet range.
Test plan
Supersedes meshcore-dev#1249
Update 24 February 2026: someone pointed to me that Heltec does the same in their ESP32 library, so I'm certain this is the right way of holding the GC1109 awake during sleep.
Build firmware: Build from this branch
Mirror of meshcore-dev#1600