diff --git a/examples/simple_sensor/SensorMesh.cpp b/examples/simple_sensor/SensorMesh.cpp
index 92a57f83..df568ddf 100644
--- a/examples/simple_sensor/SensorMesh.cpp
+++ b/examples/simple_sensor/SensorMesh.cpp
@@ -50,6 +50,7 @@
 #define REQ_TYPE_GET_STATUS          0x01
 #define REQ_TYPE_KEEP_ALIVE          0x02
 #define REQ_TYPE_GET_TELEMETRY_DATA  0x03
+#define REQ_TYPE_GET_AVG_MIN_MAX     0x04
 
 #define RESP_SERVER_LOGIN_OK      0   // response to ANON_REQ
 
@@ -154,6 +155,22 @@ uint8_t SensorMesh::handleRequest(bool is_admin, uint32_t sender_timestamp, uint
       memcpy(&reply_data[4], telemetry.getBuffer(), tlen);
       return 4 + tlen;  // reply_len
     }
+    case REQ_TYPE_GET_AVG_MIN_MAX: {
+      uint32_t start_secs_ago, end_secs_ago;
+      memcpy(&start_secs_ago, &payload[0], 4);
+      memcpy(&end_secs_ago, &payload[4], 4);
+      uint8_t res1 = payload[8];   // reserved for future  (extra query params)
+      uint8_t res2 = payload[8];
+
+      MinMaxAvg data[8];
+      int n;
+      if (res1 == 0 && res2 == 0) {
+        n = querySeriesData(start_secs_ago, end_secs_ago, data, 8);
+      } else {
+        n = 0;
+      }
+      return 0;  // TODO: encode data[0..n)
+    }
   }
   return 0;  // unknown command
 }
@@ -192,6 +209,34 @@ ContactInfo* SensorMesh::putContact(const mesh::Identity& id) {
   return c;
 }
 
+void SensorMesh::sendAlert(const char* text) {
+  int text_len = strlen(text);
+
+  // send text message to all admins
+  for (int i = 0; i < num_contacts; i++) {
+    auto c = &contacts[i];
+    if (!c->isAdmin()) continue;
+
+    uint8_t data[MAX_PACKET_PAYLOAD];
+    uint32_t now = getRTCClock()->getCurrentTimeUnique();  // need different timestamp per packet
+    memcpy(data, &now, 4);
+    data[4] = (TXT_TYPE_PLAIN << 2);  // attempt and flags
+    memcpy(&data[5], text, text_len);
+    // calc expected ACK reply
+    // uint32_t expected_ack;
+    // mesh::Utils::sha256((uint8_t *)&expected_ack, 4, data, 5 + text_len, self_id.pub_key, PUB_KEY_SIZE);
+
+    auto pkt = createDatagram(PAYLOAD_TYPE_TXT_MSG, c->id, c->shared_secret, data, 5 + text_len);
+    if (pkt) {
+      if (c->out_path_len >= 0) {  // we have an out_path, so send DIRECT
+        sendDirect(pkt, c->out_path, c->out_path_len);
+      } else {
+        sendFlood(pkt);
+      }
+    }
+  }
+}
+
 void SensorMesh::alertIfLow(Trigger& t, float value, float threshold, const char* text) {
   if (value < threshold) {
     if (!t.triggered) {
@@ -222,6 +267,50 @@ void SensorMesh::alertIfHigh(Trigger& t, float value, float threshold, const cha
   }
 }
 
+void SensorMesh::recordData(TimeSeriesData& data, float value) {
+  uint32_t now = getRTCClock()->getCurrentTime();
+  if (now >= data.last_timestamp + data.interval_secs) {
+    data.last_timestamp = now;
+
+    data.data[data.next] = value;   // append to cycle table
+    data.next = (data.next + 1) % data.num_slots;
+  }
+}
+
+void SensorMesh::calcDataMinMaxAvg(const TimeSeriesData& data, uint32_t start_secs_ago, uint32_t end_secs_ago, MinMaxAvg* dest, uint8_t channel, uint8_t lpp_type) {
+  int i = data.next, n = data.num_slots;
+  uint32_t ago = data.interval_secs * data.num_slots;
+  int num_values = 0;
+  float total = 0.0f;
+
+  dest->_channel = channel;
+  dest->_lpp_type = lpp_type;
+
+  // start at earliest recording, through to most recent
+  while (n > 0) {
+    n--;
+    i = (i + 1) % data.num_slots;
+    if (ago >= end_secs_ago && ago < start_secs_ago) {
+      float v = data.data[i];
+      num_values++;
+      total += v;
+      if (num_values == 1) {
+        dest->_max = dest->_min = v;
+      } else {
+        if (v < dest->_min) dest->_min = v;
+        if (v > dest->_max) dest->_max = v;
+      }
+    }
+    ago -= data.interval_secs;
+  }
+  // calc average
+  if (num_values > 0) {
+    dest->_avg = total / num_values;
+  } else {
+    dest->_avg = NAN;
+  }
+}
+
 float SensorMesh::getAirtimeBudgetFactor() const {
   return _prefs.airtime_factor;
 }
@@ -577,7 +666,7 @@ void SensorMesh::loop() {
     // query other sensors -- target specific
     sensors.querySensors(0xFF, telemetry);  // allow all telemetry permissions
 
-    checkForAlerts();
+    onSensorDataRead();
 
     // save telemetry to time-series datastore
     File file = openAppend(_fs, "/s_data");
diff --git a/examples/simple_sensor/SensorMesh.h b/examples/simple_sensor/SensorMesh.h
index 6293b21e..0f94b128 100644
--- a/examples/simple_sensor/SensorMesh.h
+++ b/examples/simple_sensor/SensorMesh.h
@@ -93,7 +93,33 @@ protected:
   void alertIfLow(Trigger& t, float value, float threshold, const char* text);
   void alertIfHigh(Trigger& t, float value, float threshold, const char* text);
 
-  virtual void checkForAlerts() = 0;   // for app to implement
+  class TimeSeriesData {
+    public:
+      float* data;
+      int num_slots, next;
+      uint32_t last_timestamp;
+      uint32_t interval_secs;
+
+      TimeSeriesData(float* array, int num, uint32_t secs) : num_slots(num), data(array), last_timestamp(0), next(0), interval_secs(secs) { 
+        memset(data, 0, sizeof(float)*num);
+      }
+      TimeSeriesData(int num, uint32_t secs) : num_slots(num), last_timestamp(0), next(0), interval_secs(secs) {
+        data = new float[num];
+        memset(data, 0, sizeof(float)*num);
+      }
+  };
+
+  void recordData(TimeSeriesData& data, float value);
+
+  struct MinMaxAvg {
+    float _min, _max, _avg;
+    uint8_t _lpp_type, _channel;
+  };
+
+  void calcDataMinMaxAvg(const TimeSeriesData& data, uint32_t start_secs_ago, uint32_t end_secs_ago, MinMaxAvg* dest, uint8_t channel, uint8_t lpp_type);
+
+  virtual void onSensorDataRead() = 0;   // for app to implement
+  virtual int querySeriesData(uint32_t start_secs_ago, uint32_t end_secs_ago, MinMaxAvg dest[], int max_num) = 0;  // for app to implement
 
   // Mesh overrides
   float getAirtimeBudgetFactor() const override;
@@ -130,6 +156,6 @@ private:
   mesh::Packet* createSelfAdvert();
   ContactInfo* putContact(const mesh::Identity& id);
 
-  void sendAlert(const char* text) { }  // TODO
+  void sendAlert(const char* text);
 
 };
diff --git a/examples/simple_sensor/main.cpp b/examples/simple_sensor/main.cpp
index 63122e9a..500efef4 100644
--- a/examples/simple_sensor/main.cpp
+++ b/examples/simple_sensor/main.cpp
@@ -8,18 +8,28 @@
 class MyMesh : public SensorMesh {
 public:
   MyMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::MillisecondClock& ms, mesh::RNG& rng, mesh::RTCClock& rtc, mesh::MeshTables& tables)
-     : SensorMesh(board, radio, ms, rng, rtc, tables) { }
+     : SensorMesh(board, radio, ms, rng, rtc, tables), 
+       battery_data(12*24, 5*60)    // 24 hours worth of battery data, every 5 minutes
+  {
+  }
 
 protected:
-  /* ========================== custom alert logic here ========================== */
+  /* ========================== custom logic here ========================== */
   Trigger low_batt;
+  TimeSeriesData  battery_data;
 
-  void checkForAlerts() override {
-    alertIfLow(low_batt, getVoltage(TELEM_CHANNEL_SELF), 3.4f, "Battery low!");
-    // alertIf ... 
-    // alertIf ... 
+  void onSensorDataRead() override {
+    float batt_voltage = getVoltage(TELEM_CHANNEL_SELF);
+
+    recordData(battery_data, batt_voltage);   // record battery
+    alertIfLow(low_batt, batt_voltage, 3.4f, "Battery low!");
   }
-  /* ============================================================================= */
+
+  int querySeriesData(uint32_t start_secs_ago, uint32_t end_secs_ago, MinMaxAvg dest[], int max_num) override {
+    calcDataMinMaxAvg(battery_data, start_secs_ago, end_secs_ago, &dest[0], TELEM_CHANNEL_SELF, LPP_VOLTAGE);
+    return 1;
+  }
+  /* ======================================================================= */
 };
 
 StdRNG fast_rng;