Progress update time 
Our latest set of boards with changes resulting both from our EMC testing and improving performance at low power levels have come through. Results are all looking good from the testing that we’ve done on these so far and so we are happy to now proceed with getting the first batch built up.
The unit on the left is the 3-phase voltage sensing unit and combined power supply (This replaces the current use of AC-AC adapters and separate USB power supplies). The right hand unit is the new EmonTx v4:
The main changes from the EMC testing were the addition of common mode chokes to the voltage sensor to reduce conducted noise from the power supply and also improve immunity from noise injected e.g down the Ethernet of a connected RaspberryPi.
The main change to improve performance at low power levels was to change the way the CT sensors and AC voltage input’s were biased. These now have one side connected to ground and the other side connected to the bias via a DC-decoupling capacitor, this provides a better path for noise to get to ground. The DC ground is also connected to the mains ground. The result at low power is much better.
With enclosures:
ESP32 WiFi extension board with I2C LCD:
As discussed above the plan is to have the option to connect the EmonTx v4 directly to WiFi via an ESP32 module - other options include rfm69cw radio link to an emonBase or emonPi, or a direct wired USB connection. Here’s a picture of the ESP32 WiFi module with a connected I2C LCD to give feedback on connectivity etc. It’s amazing how short a time it takes the ESP32 to connect to a WiFi network! The IP address pops up almost immediately!
Next steps
We should get the assembly quotes and timelines back from the company we use to do our manufacturing soon and pending no large surprises that should give us a clearer ETA for when we will have stock.
I look forward to updating with more on all this soon!