With help from you guys, and hours poking on the web, I've managed to merge a few things together, and have managed to get a temperature uploaded to a web page on my home network, using an esp8226 01 and a Uno. The system creates its own access point (although I could predefine one). (attached wifitemp.txt)
I am wondering if I can create a separate WiFi network, just for these sensors. I've been looking, but 1) I do not understand the terminology 2) I'm confused.
I guess, what I'm ultimately looking for is to be able to access a local web page which shows various temperatures/whatever from different locations, but is not on my existing home network. I would like to be able to achieve this with esp8266's and Nanos (The Uno is easier for prototyping, I reckon).
What is your reasoning behind needing a separate network?
Creating a separate network is something that can be done and is not terribly difficult. I can think of a few reasons why one would want to do this. What you are describing doesn't seem to fall into what I would think would need a separate network. What are you trying to achieve by having a separate network?
One issue is security, another is being able to set it up remote from any existing wifi network. I'm not too bothered if someone hacks into an unsecured network of temperature sensors, but I would be if they hacked into my home network.
What sort of signal strength does the esp8266 01 achieve? In quick tests, waling about outside, using WiFi.RSSI() I find that the connection tends to disappear at around -84, the range is not as high as I hoped. I'm not sure of the units of measurement in the real world, but I would prefer something with a bit more power, I guess. (but cheap!).
Well, I've more or less completed my temperature monitor to wifi project. I've based it on a nano, the esp8266 01 and the voltage level shifting pcb. I've milled a pcb to mount it all, and it fits neatly into an RX2010 component box. I can power it from 3 AAcells, or a 5V phone charger. The voltage sensor will plug in, so easy to change it. I've incorporated an LED to indicate that the connection is made to the wifi. I will be surprised if it will run for much more than a day on batteries. I was contemplating fitting it into a smaller box, RX2008, but I would not have been able to make such a neat job of it, it would have been a tight rat's nest of wiring, and my soldering is not as good as it once was.
I put the monitor in a bedroom, the router is downstairs. I thought I'd see how long it would run on three AA cells. I was not around when the batteries got to be 'flat' (which was about 0.98V per cell when measured, but most likely a bit over 1V when the system stopped working). However, I estimate it was running for about 38 hours, with signal strength of about -70, and in total it was about 650 requests received. This was with new Duracell industrial AA's. I'm repeating with Amazon basics batteries. Although the software transmits tha data every 20 seconds, it certainly was not being received at that rate, and in fact at the low signal strength, the site was often unobtainable.