EmonTx V3
emonTx V3
The emonTx V3 is the latest generation of the open source emonTx low power wireless energy monitoring node. The unit has been re-designed using surface mount (SMT) electronics to enable automated pre-assembled manufacture.
Features
- Emontx v3 can measure real power, apparent power, power factor, rms voltage and current on 4 different mains circuits, it also has inputs for temperature and humidity sensing. - Pre-assembled SMT design - A single AC-AC adapter can now be used to power the emonTxV3 and provide AC voltage measurement - 4x CT current sensing inputs - An on-board 3x AA battery option - Flexible choice of RF radio module and removable microcontroller
Port Map
Overview
Power Supply Options
Uploading Firmware
Start by downloading the firmware, libraries and setting up the Arduino programming environment by following this guide:
Setup the Arduino Programming environment
Once complete the emonTx firmware location should be navigable from within the Arduino IDE by going to:
File > Sketchbook > OpenEnergyMonitor > emonTxFirmware > emonTxV3
These are the examples available so far:
RFM12B
emonTxV3_RFM12B_DiscreteSampling
Examples: emonTxV3_4chan_continuous emonTxV3_CurrentOnly emonTxV3_RealPower_Voltage
SRF
SRF___Low_Power___Current_only_Apparent_Power
The emontx firmware is available on github here: Github:emonTxFirmware
Standard Operation
CT Energy Monitoring
Single Phase
Three-Phase
Accuracy
Extended Operation
Temperature Monitoring
Utility Meter Interface
Optical Pulse Counting
Direct Optical Interface
if you have an Elster meter (tested with Elster 100C) the emonTx V3 with an IR TSL261R sensor can be used to interface directly with the meter protocol to read off the exact accumulated watt hours that you have generated or used. This reading can be used on it's own or to cross-check and calibrate CT based measurement. See here for original blog post
RF Connectivity
RFM12B
SRF
Electrical Characteristics
power consumption, absolute max values
Open-Hardware Design Files
Proudly open source, the hardware designs are released under the Creative Commons Attribution-ShareAlike 3.0 Unported License:
Download Schematic PNG: emontx-v3.png
Download Schematic: emonTx V3.2.sch
Download Board files: emonTx V3.2.brd