Tag Archives: emonPi

Let the Raspberry Pi Monitor Energy

If you are looking for monitoring energy remotely, an open source system that uses the ever-popular single board computer, the Raspberry Pi (RBPi) may be suitable. The company, OpenEnergyMonitor, makes the open-source tools for monitoring energy, and at present, they are using the RBPi3. According to their co-founder Glyn Hudson, the aim of OpenEnergyMonitor is to help people understand and relate to how they use energy from their energy systems, and the challenges of sustainable energy.

The system uses five main units. Users can assemble and configure these to work in a variety of applications. Both hardware and software in the system is fully open-source, and the hardware is based on Arduino and RBPi platforms. Users can opt to use the system for monitoring home energy, monitoring solar PV, and or monitoring temperature and humidity.

emonPi

When configuring the OpenEnergyMonitor system, emonPi, as a simple home energy monitoring system, it allows measuring the daily energy consumption and analyzing real-time power use. The all-in-one energy-monitoring unit, emonPi is a simple installation based on the RBPi, requiring only an Ethernet or Wi-Fi connection at the meter location.

Clip-on CT sensors on the emonPi enable it to monitor independently two single-phase AC circuits simultaneously. While the emonPi can monitor temperature, it has an optical pulse sensor to interface directly with the utility meters, which means the emonPi has to be installed next to the utility meter.

The emonPi comes with Emoncms, the open-source web application. This helps in logging and visualizing energy use along with other environmental data such as temperature and humidity. It has two power outlets and requires Ethernet or Wi-Fi to transfer data. The RBPi operates on a pre-built OS on an SD card included with the energy monitor. The 5 VDC power required has to be fed in from an external power supply unit.

As power is the product of voltage and current, the emonPi requires an AC-AC voltage sensor adaptor and a clip-on CT sensor. While the emonPi comes with one CT sensor as standard, it can accept two CT sensors.

emonTx

For remote monitoring, users can use emonTx, a remote sensor node as an alternative to emonPi. The emonTx runs as a standalone unit, with an ESP8266 Wi-Fi module running EmonESP. This can post directly to Emoncms without using emonPi or emonBase.

Users can monitor a maximum of four single-phase AC circuits with the clip-on CT sensors using the emonTx. A plug-in AC-AC adaptor powers the unit, and provides the AC voltage sample, which the emonTx uses for real-time power calculations. If AC power is not available, emonTx can be powered using four AA type batteries.

Optional LED Pulse Sensor for Utility Meter

This sensor allows interfacing directly with utility meters that have LED pulse output. It is compatible with emonTx and emonPi, and reports the exact amount of energy as the utility meter does. Although best used together with clip-on CT sensors, the LED pulse sensor cannot measure instantaneous power.

emonBase

This is a web-connected gateway, consisting of an RBPi and RFM69Pi RF receiver board. It receives data via a low power RF carrier at 433 MHz from emonTx or emonTH and offers local and remote data logging using Emoncms.

Energy Monitoring with the Raspberry Pi

If you are looking for an all-in-one device for monitoring your home energy needs, a low-cost single board computer such as the RBPi or Raspberry Pi along with an add-on shield is all you need. The emonPi board is a low-cost shield that is bereft of any enclosure, HDD and LCD.

However, when connected with an LCD for status display, hard-drive for local logging and backup and a web-connected RBPi, the emonPi makes a high-quality and robust unit. Enclose it in a suitable enclosure and you have a stand-alone energy monitoring station.

The design of the emonPi allows it to be a perfect fit for those who install heat-pump monitoring systems. Usually, these systems require several temperature sensors that must also be wired up along with power monitoring. Accompanying modules offer a myriad of options.
For example, the emonPi can also act as an emonBase, as it has options for rad
io (RFM12B/RFM69CW) to receive data from other wireless nodes. These nodes include emonTH, for measuring room temperature and humidity. Another energy-monitoring node, the emonTX V3 can send the current time to the LCD, emonGLCD.

The status LCD makes it easy to install, setup and debug the emonPi system as an energy monitor sensing mode and an all-in-one remote posting base station. This makes the emonPi a great tool for remote administration, since, with a proper networking configuration the RBPi can be accessed remotely. Thus, you may check its log files and even upload firmware onto the ATmega328 of the emonPi.

The emonPi monitors energy through a two-channel CT or current transformer along with an AC sample input. It can power up the RBPi and an external hard disk drive without using an external USB hub. Additionally, the emonPi can function even without a hard disk drive being connected to it.

The RJ45 breakout board makes it very easy to attach several temperature sensors to the RJ45 on-wire temperature bus provided by a DS18B20. This is eminently suitable for multi-sensor setups such as in heat pump monitoring applications. The RJ45 also has IRW and PWM I/Os.

The emonPi is compatible to all models of the RBPi and its options for RFM21B and RFM69CW along with an SMA antenna makes it capable of receiving or transmitting data from other sensor nodes. One can control remote plugs with the OOK or On-Off keying transmitter.

All hardware, firmware and software are open-source and the ATmega328 on the emonPi can remotely upload sketches via the serial port of the RBPi. However, compared to the emonTX V3, emonPi has some disadvantages.

The emonPi module is not capable of making measurements on three-phase systems as there is only one CT monitoring two channels. As the RBPi has high power requirements, it is not possible to power the emonPi from batteries. You cannot also use an AC-AC adapter, because, for measuring real power, you must use both a 5VDC and a 9VAC adapter. Remote location of the utility meter requires Ethernet connection or Wi-Fi connectivity. Additionally, the emonPi requires a larger enclosure as compared to what an emonTX V3 uses.

Energy Monitoring with the Raspberry Pi

If you are looking for an all-in-one device for monitoring your home energy needs, a low-cost single board computer such as the RBPi or Raspberry Pi along with an add-on shield is all you need. The emonPi board is a low-cost shield that is bereft of any enclosure, HDD and LCD.

However, when connected with an LCD for status display, hard-drive for local logging and backup and a web-connected RBPi, the emonPi makes a high-quality and robust unit. Enclose it in a suitable enclosure and you have a stand-alone energy monitoring station.

The design of the emonPi allows it to be a perfect fit for those who install heat-pump monitoring systems. Usually, these systems require several temperature sensors that must also be wired up along with power monitoring. Accompanying modules offer a myriad of options.

For example, the emonPi can also act as an emonBase, as it has options for radio (RFM12B/RFM69CW) to receive data from other wireless nodes. These nodes include emonTH, for measuring room temperature and humidity. Another energy-monitoring node, the emonTX V3 can send the current time to the LCD, emonGLCD.

The status LCD makes it easy to install, setup and debug the emonPi system as an energy monitor sensing mode and an all-in-one remote posting base station. This makes the emonPi a great tool for remote administration, since, with a proper networking configuration the RBPi can be accessed remotely. Thus, you may check its log files and even upload firmware onto the ATmega328 of the emonPi.

The emonPi monitors energy through a two-channel CT or current transformer along with an AC sample input. It can power up the RBPi and an external hard disk drive without using an external USB hub. Additionally, the emonPi can function even without a hard disk drive being connected to it.

The RJ45 breakout board makes it very easy to attach several temperature sensors to the RJ45 on-wire temperature bus provided by a DS18B20. This is eminently suitable for multi-sensor setups such as in heat pump monitoring applications. The RJ45 also has IRW and PWM I/Os.

The emonPi is compatible to all models of the RBPi and its options for RFM21B and RFM69CW along with an SMA antenna makes it capable of receiving or transmitting data from other sensor nodes. One can control remote plugs with the OOK or On-Off keying transmitter.

All hardware, firmware and software are open-source and the ATmega328 on the emonPi can remotely upload sketches via the serial port of the RBPi. However, compared to the emonTX V3, emonPi has some disadvantages.

The emonPi module is not capable of making measurements on three-phase systems as there is only one CT monitoring two channels. As the RBPi has high power requirements, it is not possible to power the emonPi from batteries. You cannot also use an AC-AC adapter, because, for measuring real power, you must use both a 5VDC and a 9VAC adapter. Remote location of the utility meter requires Ethernet connection or Wi-Fi connectivity. Additionally, the emonPi requires a larger enclosure as compared to what an emonTX V3 uses.