Multiple ESP8266 in a chain to link RS485

Hi Everyone.

First of all I wanna mention that I just registered now and received today my parcel with an Arduino Kit. I already have a few Raspberry Pis but used them more as small server’s, Kodi/XBMC, …

I’m Electrician and Network Administrator by trade. I know that doesn’t mean anything, I’m still young and learning. :slight_smile:

After this quick introduction I think it is time to explain what I’d like to do with an Arduino and a few ESP8266 modules.

I’m working as an Electrician again and we’re Installing solar farms in scales from 200kw (450kW Inverters) to 1MW (2050kW inverters).
The inverters we’re using is ‘ABB Trio 50 TL OUTD’.
For Monitoring, Data logging and configuration we wire all the Inverters parallel together with an twisted pair cable which goes underground trough conduits to all the Inverters.
I’m not an native English speaker and know that I struggle sometimes explaining myself properly. For this reason I attached an document which could make it easier to understand the actual situation.

Now… What I’d like to do is using ESP8266’s in each housing of the inverter. Hook up the 2 RS485 cables and obviously power supply.
Luckily there is 5V (max 800mAh) already present in the Board which I can use for power supply. For his reason I choose the NodeMCU ESP8266, just to avoid using an extra Lm1117 or any kind of regulator.

Also for this I attached an document. (The drawings are not really professional, sorry for that. Just done them quickly on my Phone)

My plan is to get rid of cables, burried underground and realise it with WiFi.
In some cases I maybe could set up an access point to get them all hooked up, bit what I’d prefer is, that the ESP8266’s are linked with each other in a chain. With this I could manage it easier to linked them over long distances. Sometimes the inverters are ~25 Metres apart. Which means a lot longer distance between #1 and #20.

Now I’m looking forward to get somehow started with this project.
I appreciate any helpful answer.

Cheers

Berri

The datasheet says there are optional Wifi cards:
Remote monitoring: VSN300 Wifi Logger Card (opt.), VSN700 Data Logger (opt.)
Wireless local monitoring: VSN300 Wifi Logger Card (opt.)

Are these too expensive?

Any particular reason for wanting ESP8266 modules (apart from cheapness)?
I would normally think of using something like a mesh network with NRF24L01+ modules for a job like this but a quick google shows people have used ESP8266 mesh networks

mikb55:
The datasheet says there are optional Wifi cards:
Remote monitoring: VSN300 Wifi Logger Card (opt.), VSN700 Data Logger (opt.)
Wireless local monitoring: VSN300 Wifi Logger Card (opt.)

Are these too expensive?

It's absolutely not about the price. It's just there is next to to logging another Rs485 terminal to adjust firmware settings with the ABB Aurora's Manager software (which is remotely not possible with the original wifi card)

Once I get this running, I'd also try to get this 'rs485 over network' via an VPN running. But that is for now a another step ahead. :slight_smile:

Riva:
Any particular reason for wanting ESP8266 modules (apart from cheapness)?
I would normally think of using something like a mesh network with NRF24L01+ modules for a job like this but a quick google shows people have used ESP8266 mesh networks

I asked once for a solution in an Arduino IRC chat for my problem and someone there suggested me ESP8266.

Which benefit do you see in using NRF24L01+?

Thanks for your efforts guys.

Riva:
Any particular reason for wanting ESP8266 modules (apart from cheapness)?
I would normally think of using something like a mesh network with NRF24L01+ modules for a job like this but a quick google shows people have used ESP8266 mesh networks

'mesh networks' that's the keyword I'm looking for. I just did a small research about it, and it seems to suit my needing.
I'll read more about this tomorrow and then look forward to get into it on the weekend.

Cheers

I had a little research and got sidetracked with Wifi2Serial Bridge.
Which TCP to rs485 bridge could you guys recommend. I'd need it like it was wired. (i.e. COM3)

I ordered now a few more ESP8266 and probably get into painlessMesh soon.