Hi, first post UwU.
I want to run my own server in docker on the lan, and run around the house measuring 3-phase consumption in different locations.
So, little interest in 433Mhz.
If I source my own Adafruit HUZZAH ESP8266 Breakout or similar, how do I add it to a emonTx?
(The preinstalled version is not in stock at the shop)
I do have usb uart dongles.
Additionally, will the 3 X AA Battery Holder be able to power it:
You can either add it on the outside, as the original prototype (that’s before provision was made on the PCB of the emonTx to mount it in place of the battery holder), or if your emonTx has the second FTDI connector in the centre of the PCB, then you can have it inside the case.
The original instructions, including the software download, are here:
CAREFULLY NOTE that the emonTx sends its data on the Rx pin (i.e. the pin marked “Rx” is looking for the Rx pin on the ESP) and it must not receive any data from the ESP. If it does, unwanted characters sent at startup can reconfigure the emonTx in an unpredictable way.
You will need a programmer (a) to load the ESP software and (b) if you need to change the sketch.
There are several issues here.
You will probably need high power rechargeable cells if you do try to operate on battery power, for permanent installation we recommend a 5 V USB supply, because battery life would be extremely short, and the a.c. adapter cannot provide sufficient current without seriously distorting the wave you are tying to measure (so it is current-limited and the emonTx will crash if you try it).
If you want “voltage-less”, you cannot use the 3-phase sketch, because it phase locks to the a.c. voltage in order to measure real power across the three phases. You must use the standard single-phase sketch and measure only current, and allow the sketch to calculate a ‘best guess’ apparent power based on an assumed voltage.
I have received my items, (they were stuck in Cyprus customs at the airport for over 2 months)
I am getting these types of measurements:
MSG
633
Vrms
246.14 V
P1
148 W
P2
-112 W
P3
-96 W
P4
46 W
E1
276 Wh
E2
-259 Wh
E3
-130 Wh
E4
90 Wh
pulse
1
Is just logging data from P1-4 and Vrms enough to calculate true power?
Or is there a different firmware I need to flash to the emonTx (not the ESP8266) to calculate that in real time instead?
That looks to be the case, as you do indeed have a voltage to provide the information necessary to calculate real power. If you download if from the forum, it comes in a zip file with full written instructions in a pdf file.
You will want to disable the radio as you’re using WiFi, so the choice of “classic” or “Native” format does not concern you.
Have a search for PiZeroW - I favour connecting up EmonTX via a PiZero to read the serial data. There are quite a few discussions on how to do that. Other suggestions include a Serial to Ethernet adapter as well.
I’d say almost certainly not - unless you only want it to operate for maybe a day - Current consumption analytics on ESP8266 for battery users - Everything ESP8266 says “in my experience a typical 2500mA AAx3 will give you approx 30hours of continuous service.” and that’s reduced by the power consumption of the emonTx itself.
