Initial commit

src/json_codec.cpp

@@ -0,0 +1,55 @@
+#include "json_codec.h"
+#include <ArduinoJson.h>
+#include <math.h>
+
+bool meterDataToJson(const MeterData &data, String &out_json) {
+  StaticJsonDocument<256> doc;
+  doc["id"] = data.device_id;
+  doc["ts"] = data.ts_utc;
+  doc["energy_kwh"] = data.energy_total_kwh;
+  doc["p_total_w"] = data.total_power_w;
+  doc["p1_w"] = data.phase_power_w[0];
+  doc["p2_w"] = data.phase_power_w[1];
+  doc["p3_w"] = data.phase_power_w[2];
+  doc["v1_v"] = data.phase_voltage_v[0];
+  doc["v2_v"] = data.phase_voltage_v[1];
+  doc["v3_v"] = data.phase_voltage_v[2];
+  doc["bat_v"] = data.battery_voltage_v;
+  doc["bat_pct"] = data.battery_percent;
+
+  out_json = "";
+  size_t len = serializeJson(doc, out_json);
+  return len > 0 && len < 256;
+}
+
+bool jsonToMeterData(const String &json, MeterData &data) {
+  StaticJsonDocument<256> doc;
+  DeserializationError err = deserializeJson(doc, json);
+  if (err) {
+    return false;
+  }
+
+  const char *id = doc["id"] | "";
+  strncpy(data.device_id, id, sizeof(data.device_id));
+  data.device_id[sizeof(data.device_id) - 1] = '\0';
+
+  data.ts_utc = doc["ts"] | 0;
+  data.energy_total_kwh = doc["energy_kwh"] | NAN;
+  data.total_power_w = doc["p_total_w"] | NAN;
+  data.phase_power_w[0] = doc["p1_w"] | NAN;
+  data.phase_power_w[1] = doc["p2_w"] | NAN;
+  data.phase_power_w[2] = doc["p3_w"] | NAN;
+  data.phase_voltage_v[0] = doc["v1_v"] | NAN;
+  data.phase_voltage_v[1] = doc["v2_v"] | NAN;
+  data.phase_voltage_v[2] = doc["v3_v"] | NAN;
+  data.battery_voltage_v = doc["bat_v"] | NAN;
+  data.battery_percent = doc["bat_pct"] | 0;
+  data.valid = true;
+
+  if (strlen(data.device_id) >= 8) {
+    const char *suffix = data.device_id + strlen(data.device_id) - 4;
+    data.short_id = static_cast<uint16_t>(strtoul(suffix, nullptr, 16));
+  }
+
+  return true;
+}