diff --git a/meshtastic/powermon.proto b/meshtastic/powermon.proto
new file mode 100644
index 00000000..763801c4
--- /dev/null
+++ b/meshtastic/powermon.proto
@@ -0,0 +1,43 @@
+syntax = "proto3";
+
+option csharp_namespace = "Meshtastic.Protobufs";
+option go_package = "github.com/meshtastic/go/generated";
+option java_outer_classname = "PowerMonProtos";
+option java_package = "com.geeksville.mesh";
+option swift_prefix = "";
+
+package meshtastic.PowerMon;
+
+/* Any significant power changing event in meshtastic should be tagged with a powermon state transition.
+  If you are making new meshtastic features feel free to add new entries at the end of this definition.
+*/
+enum State {
+  None = 0;
+
+  CPU_DeepSleep = 0x01;
+  CPU_Sleep = 0x02;
+  CPU_Awake = 0x04;
+  Lora_RXOn = 0x08;
+  Lora_TXOn = 0x10;
+  Lora_RXActive = 0x20;
+  BT_On = 0x40;
+  LED_On = 0x80;
+
+  Screen_On = 0x100;
+  Screen_Drawing = 0x200;
+  Wifi_On = 0x400;
+  GPS_LowPower = 0x800;
+  GPS_MediumPower = 0x1000;    
+  GPS_HighPower = 0x2000;
+}
+
+/*
+  the log messages will be short and complete (see PowerMon.Event in the protobufs for details). 
+  something like "PwrMon,C,0x00001234,REASON" where the hex number is the bitmask of all current states. 
+  (We use a bitmask for states so that if a log message gets lost it won't be fatal)
+*/
+message Event {
+
+  // Bitwise-OR of States
+  optional uint64 states = 1;
+}
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