# 🔌 Echelon 83331, 83332 MEP Sniffer with ESP32

A project for reading raw data from the MEP port of the Echelon 83331 electricity meter using an ESP32. Data is read in RAW format for later parsing and decryption with a locally stored encryption key.

## 🎯 Purpose

- Read measurement data directly from the meter's MEP port.
- Avoid dependencies like SaveEye, cloud services, or MQTT.
- Store and parse all data 100% locally.
- Later send data to Home Assistant via REST API.

---

## 🔌 Hardware Connection

### 📟 Components
- ESP32 DevKit (WROOM recommended)
- RJ12 female socket or MEP adapter
- Optional logic level shifter (if MEP port uses RS-232 instead of TTL)
- Jumper wires

### ⚙️ MEP RJ12 Pinout (standard):

| Pin | Signal        | Example ESP32 GPIO |
|-----|---------------|--------------------|
| 1   | GND           | GND                |
| 2   | VCC (3.3/5V)  | 3.3V / 5V (check meter specs) |
| 3   | TX from meter | GPIO16 (RX)        |
| 4   | RX to meter   | GPIO17 (TX)        |
| 5–6 | Not used      | –                  |

> ⚠️ Double-check voltage and signal type – if RS-232 is used, insert a MAX3232 between ESP32 and the meter.

---

## 📊 Expected Data Output

Once decoding is active and the correct encryption key is implemented, the following output is expected from the meter:

| Field                       | Unit     | Description                              |
|----------------------------|----------|------------------------------------------|
| `meterType`                | String   | Meter type (e.g., "MEP meter")           |
| `meterSerialNumber`        | String   | Serial number of the meter               |
| `wifiRssi`                 | dBm      | Signal strength (only relevant for WiFi) |
| `activeActualConsumption`  | Watt (W) | Instantaneous active consumption         |
| `activeActualProduction`   | Watt (W) | Instantaneous production (e.g., solar)   |
| `activeTotalConsumption`   | Wh/kWh   | Accumulated consumption                  |
| `activeTotalProduction`    | Wh/kWh   | Accumulated production                   |
| `reactiveActualConsumption`| VAr      | Instantaneous reactive consumption       |
| `reactiveActualProduction` | VAr      | Instantaneous reactive production        |
| `rmsVoltage` (L1–L3)       | Volt (V) | RMS voltage per phase                    |
| `rmsCurrent` (L1–L3)       | mA / A   | RMS current per phase                    |
| `powerFactor`              | %        | Power factor (e.g., 98 = 0.98 cos(φ))    |

> Note: Some values depend on the meter's firmware and configuration.

---

## 🔍 ESP32 Sniffer Code (Arduino C++)

Use this code to log raw data from the meter in HEX format for analysis:

```cpp
#include <HardwareSerial.h>

HardwareSerial MEP(2);  // UART2

void setup() {
  Serial.begin(115200);
  MEP.begin(9600, SERIAL_8N1, 16, 17); // RX=GPIO16, TX=GPIO17

  Serial.println("🔍 Starting MEP sniffer...");
}

void loop() {
  while (MEP.available()) {
    byte b = MEP.read();
    if (b < 0x10) Serial.print("0");
    Serial.print(b, HEX);
    Serial.print(" ");
  }
}
```

👉 Once connected and receiving data, bytes will appear in the Serial Monitor (baud: 115200).

---

## 🔐 Encryption Key

The project will later use the meter’s **private encryption key** (if required) to:
- Authenticate with the meter
- Decrypt binary data into readable values

### 🔒 Security Measures
- The key will be **hardcoded in firmware**.
- Changes require OTA or physical update – **no access via web or serial interface**.
- Key usage will be handled in a dedicated parsing section.

---

## 🧪 Next Steps

1. Use this sniffer to log a data dump from the meter.
2. Compare values with your known usage/voltage to identify structure.
3. We will implement parsing + decryption, and REST push to Home Assistant.

---

## 📬 Contact

> Developed and maintained by [Thomas Emil](https://www.linkedin.com/in/thomas-emil-b3497995/).  
> For technical questions, reach out via GitHub Issues or ESP32 RF-beams 💡