Initial commit: Simple Sensor firmware for Heltec T114 with BME280

- MeshCore-based Simple Sensor firmware
- Heltec T114 without display
- BME280 sensor support (temp/humidity/pressure)
- Radio: 868.856018 MHz, SF7, BW62.5 kHz, CR4/7
- 2-byte path hash
- PlatformIO project

examples/simple_sensor/TimeSeriesData.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <Arduino.h>
+#include <Mesh.h>
+
+struct MinMaxAvg {
+  float _min, _max, _avg;
+  uint8_t _lpp_type, _channel;
+};
+
+class TimeSeriesData {
+  float* data;
+  int num_slots, next;
+  uint32_t last_timestamp;
+  uint32_t interval_secs;
+
+public:
+  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(mesh::RTCClock* clock, float value);
+  void calcMinMaxAvg(mesh::RTCClock* clock, uint32_t start_secs_ago, uint32_t end_secs_ago, MinMaxAvg* dest, uint8_t channel, uint8_t lpp_type) const;
+};
+