So having done some reading this morning it would seem that if I want to go down the PiZero route I need the following:
PiZero 2 (I believe that is the current version)
2)MicroSD card
Software for the above (this I’m currently confused about because as far as I understand the role of the Pizero is to accept the data from the EmonTX and transmit it on to another local device (or in my case cloud)
PSU for the Zero Pi (Note to self - check if the EmonTX stiff needs a 5v supply)
The PiZero devices didn’t exist when I got into emon, my emonTX V2 is still going strong handling my power reporting as well as Solar Diversion.
So instead I used an OpenWRT device that basically is the same as a PiZero but without needing an SD card. All it does is just reads the emonTX’s serial port and pushes that data directly to emonCMS via its HTTP csv input. I have updated that to also push that csv string to MQTT too.
If you’re only using the serial port, and not drawing any power from the emonTx (i.e. whatever you connect to it is powered from somewhere else), then the a.c. adapter can supply enough power to the emonTx. The trouble starts when you connect something that needs more than a few milliamps, because the extra current spoils the shape of the wave you’re measuring, and makes the readings wrong.
OpenWRT was never a device as such. It was a linux operating system that you could run on several embedded hardware platforms. I ran it on a cheap TL link router. The advantage is that the TL link device had a serial port input, a WiFi adapter and a LAN port. So everything I needed to simply build a bridge between a serial port and the LAN. You don’t need to do any of that now. There are several off the shelf serial to LAN devices available.
Or just use an ESP (or similar), if you are happy with WiFi.
I have also used devices that provide a cheap Serial to Ethernet bridge.
And while they work fine, they are closed firmware and that means that you need some scripting on the emoncms server to read the data from the LAN device it creates and push that into emonCMS or similar.
e.g.
￡6.46 10%OFF | FS100P USR-TCP232-T2 Tiny Serial Ethernet Converter Module Serial UART TTL to Ethernet TCPIP Module Support DHCP and DNS
I was just looking at that and trying to figure out just how @bruce_miranda used it - it looks like a wireless access point to me - Ethernet ↔ WiFi, which I think isn’t how we use the PiZeroW, or the plain RPi or ESP8266/
Trust me it has a serial port, but you need to solder 3 wires to gain access to it. Very easy to do. The beauty is that you then have access to a small network connected Linux box that you can do so much with.
That device can have OpenWRT loaded on it too. And I will bet it has a Serial port on board the PCB too, which is what the current USB is connected to.
I’m hoping to do some playing/testing with the data stream over the next few days.
Thanks to everyone who has offered me help on this so far. I now have a better understanding of what role the emontx actually plays in the open energy monitoring solution.
It has been quite a while since I did anything with this, but you may want to have a “programmer” as well - IIRC I used that to flash the EmonTX. Available from the OEM Shop for not-a-lot. Programmer - USB to serial UART - Shop | OpenEnergyMonitor
I second that. We always advise people to have a programmer. For the extra cost, it means that there’s a method available to diagnose faults or make adjustments.
I just wanted to come back on and say “thanks” to everyone who responded to my question.
In the end I have gone back to basics and looked at what I was trying to achieve so I invested in an add on wifi module from the open energy shop (excellent service BTW). so I now have the emontx pumping data up to emoncms. Well, when I say data I mean readings with zeroes in because the emontx is on my desk and the clamps aren’t yet in place.
Understanding how this llot fits together is a big step forward to me so once again thank you everyone.
