# System Overview The OpenEnergyMonitor system has the capability to monitor electrical energy use / generation, temperature and humidity. The system is made up of five main units. These can be configured to work for a variety of applications. The system is fully open-source, both hardware and software. All hardware is based on the [Arduino](http://www.arduino.cc/) and [Raspberry Pi](http://raspberrypi.org) platforms. % ![image](img/oemfpsystemdiagram.png)

Current system

```{image} img/emontx4-min.png :width: 50px :align: left ``` **emonTx v4:** A 6x circuit energy monitoring node. Transmits data via an inbuilt 433MHz radio to an emonBase. It can also send data via a Wi-Fi extension board or directly via USB.

```{image} img/emonVs-min.png :width: 50px :align: left ``` **emonVs v1.1:**
Combined precision voltage sensor and power supply.

```{image} img/emonbase-min.png :width: 50px :align: left ``` **emonBase:** A Raspberry Pi base-station that receives data sent from the emonTx4. Hosts the emonCMS software for full local data logging and visualisation capability. With new direct SPI RFM69 radio transceiver.

```{image} img/ctsensor.png :width: 50px :align: left ``` **CT sensor:** Current transformer. Used for measuring AC current. We use a non-invasive clip-on sensor for ease of installation and safety.

```{image} img/emoncms-min.png :width: 50px :align: left ``` **emonCMS:** An open-source web application, for processing, logging and visualising energy, temperature and other data. Runs locally on the emonPi and emonBase, also available remotely via emoncms.org.
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Earlier hardware

```{image} img/emonpi-min.png :width: 50px :align: left ``` **emonPi:** An all in one 2 circuit energy monitor and base-station which collects data, hosts the emonCMS software and can also receive data from other sensor nodes.

```{image} img/emontx-min.png :width: 50px :align: left ``` **emonTx V3.4:** A 4 circuit energy monitoring node. Transmits data via an inbuilt 433MHz radio to an emonBase or emonPi. It can also send data via an ESP8266 WiFi adapter or directly by a serial connection.

```{image} img/emonth-min.png :width: 50px :align: left ``` **emonTH:** A battery powered, wireless, room based temperature & humidity monitoring node. Transmits data via 433MHz radio to an emonBase or emonPi.

```{image} img/voltagesensor.png :width: 50px :align: left ``` **ACAC Voltage sensor:** An AC-AC Voltage adapter, used for measuring AC Voltage safely. Used in conjunction with the AC current measurement to calculate power consumption accurately.

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