The emonTx v4 is the latest generation of OpenEnergyMonitor open source monitoring hardware, redesigned with a focus on higher accuracy, more CT channels, precision voltage sensing and a new microcontroller core. When combined with the new emonVS voltage sensor, the emonBase base-station and a selection of CT sensors, it provides an end-to-end electricity monitoring solution perfect for monitoring home consumption, solar generation, EV charging, heat pumps, battery storage or any AC electrical circuit for that matter.
6x clip-on CT current sensor inputs (suitable for a range of 333mV voltage output CT sensors).
emonVs precision voltage sensor input.
Full Real/Active power measurement & continuous sampling.
Cumulative energy persisted on reboot.
The initial firmware release supports single phase monitoring only.
Hardware support for 3 phase voltage sensing (3-phase firmware available 2023).
3 pluggable terminal block inputs for DS18B20 temperature sensing, pulse counting or an analogue voltage input.
RJ45 socket for pulse counting and DS18B20 temperature sensors.
On-board USB to UART converter for easier programming and serial output.
433 MHz radio transceiver
Extension header pins for use with ESP8266, ESP32, Pi Pico & Pi Zero development board extension modules
Wall-mount aluminium enclosure
We have taken several key steps to improve accuracy with the emonTx4. The largest source of improvement comes from: a higher accuracy voltage sensor, higher accuracy CT current sensors and a wider range of CT sensors with current ratings that can better suit the load being monitored (making sure the analog-to-digital range of the microcontroller is being put to full use).
The key sensor and component tolerances are now:
CT Sensors: ±0.5%
EmonVs voltage sensor: ±0.5%
Analog voltage reference ±0.2%
We have also upgraded the microcontroller from the ATmega328 to and AVR128DB48. The main improvement is a higher resolution ADC at 12-bits (4x the resolution of the ATmega328) alongside the capability to monitor more channels.