Just random thoughts... 0.1C accuracy is hard to come by. You don't need a PC, a wifi connection will get you directly to the internet, through your access point. You can deep sleep a processor and wake up every five minutes to do work, and go back to sleep. Wifi range might be an issue.
Not only is 0.1 deg a bit fanciful, you might also consider whether you really need it.
Also consider reading up on Internet of Things.
hardware may be as simple as DS18B20 ESP-01
Battery of some sort.
Thank you both, especially Nick. I’m already using an Arduino to read a DS18B20 to a resolution of 0.1°C, and with some calibration an accuracy of 0.1° C doesn’t seem too hard. What am I missing here?
That Internet of Things tutorial was really excellent, and taught me a lot. I thought writing a webserver would be way beyond my capabilities, the modifying that code might be just about within them.
I run DS18B20 at its maximum resolution, but Dallas only claim an accuracy of +/- 0.5 C. I'm interested in degrees of change from previous at rapid intervals. I can't imagine anything in a garden that requires an accuracy of 0.1 C and there would be all sorts of unknowables getting into the act. I don't think calibrating a DS18B20 would be worth the effort, and particularly not for this purpose. If you really want some laboratory-grade gear, you might be using the wrong sensor.
Nick_Pyner:
I can't imagine anything in a garden that requires an accuracy of 0.1 C
Actually knowing if the temperature in a greenhouse is +0.5°C or -0.5°C is the only thing that really matters to a gardener. Like you, most product manufacturers haven’t worked this out.
What sensor would you recommend for better accuracy?
emodeler:
Actually knowing if the temperature in a greenhouse is +0.5°C or -0.5°C is the only thing that really matters to a gardener. Like you, most product manufacturers haven’t worked this out.
What sensor would you recommend for better accuracy?
Kind regards, Neil.
If you have a really small greenhouse, a single sensor just might show you the meperature of your greenhouse. But for other sizes, you will likely need multiple sensors.
It’s not just the sensor , it’s positioning is important , and how it connects to what you are measuring in practice ( for example the temperature within your greenhouse will vary with height and position) to get 0.1C accuracy ( not resolution) is difficult .
In practice a DS18b20 is as good as you’ll get - check out the prices of accurate calibration equipment ( which will need re calibrating every year ) to give yourself a feeling of where you are !
Use a DS180B20. Just be aware that while it may give you a temperature with 0.1 degree precision, it's not actually that accurate. But as you say, for gardening, it doesn't matter.