diff --git a/meshtastic/config.proto b/meshtastic/config.proto
index 7805f71..391cb7d 100644
--- a/meshtastic/config.proto
+++ b/meshtastic/config.proto
@@ -409,6 +409,12 @@ message Config {
      * I2C address of INA_2XX to use for reading device battery voltage
      */
     uint32 device_battery_ina_address = 9;
+
+    /*
+     * If non-zero, we want powermon log outputs.  With the particular (bitfield) sources enabled.
+     * Note: we picked an ID of 32 so that lower more efficient IDs can be used for more frequently used options.
+     */
+     uint64 powermon_enables = 32;    
   }
 
   /*
diff --git a/meshtastic/powermon.proto b/meshtastic/powermon.proto
new file mode 100644
index 0000000..8f328b5
--- /dev/null
+++ b/meshtastic/powermon.proto
@@ -0,0 +1,54 @@
+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_LightSleep = 0x02;
+
+  /*
+  The external Vext1 power is on.  Many boards have auxillary power rails that the CPU turns on only
+  occasionally.  In cases where that rail has multiple devices on it we usually want to have logging on
+  the state of that rail as an independent record.
+  For instance on the Heltec Tracker 1.1 board, this rail is the power source for the GPS and screen.
+  */
+  Vext1_On = 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 is actively trying to find our location
+  See GPSPowerState for more details
+  */
+  GPS_Active = 0x800;
+}
+
+/*
+  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;
+}
\ No newline at end of file