Here's a quick comparison table comparing the emonPi (currently active on Kickstarter!) to our existing emonTx V3 energy monitoring unit:
It is no secret that there is much similarity between the two units, both are cut from the same cloth. Both units use the same ATmega328 Arduino IDE compatible microcontroller and front-end CT channel signal processing which gives identical monitoring accuracy.
The emonPi is most suitable over the emonTx V3 for home or small business whole circuit energy monitoring and also solar PV where Ethernet or WIFI can reach the consumer unit. Being a one-box-solution and with its status LCD the emonPi is quick and simple to install and maintain.
For larger systems where there could be multiple transmitter nodes and more channels to be monitored the emonTx V3 could be most suitable. The emonTx V3 transmits it's readings via RF (433Mhz) to an emonBase web-connected base station (Raspberry Pi + RFM69Pi). Multiple emonTx V3's can be used with a single emonBase
The emonTx V3 has the edge over the emonPi when it comes to powering the unit, the emonTx V3 can be powered directly from the AC-AC adapter while also taking an AC voltage waveform sample. Due to the higher power requirements of the Raspberry Pi the emonPi requires an additional 5V DC USB adapter.
Struggling to decide? It's also worth noting that the emonPi and emonTx V3 can work together. emonPi by default also functions as an emonBase; as well as local monitoring the emonPi can receive data via RF from multiple emonTx V3 and other remote nodes such as emonTH temperature and humidity room node.
For further details of the units see the Technical Wiki documentation pages.
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