ESP8266 Community Forum

Hello
I plan to use a spare ESP8266 I have as a connected fridge thermometer. I'd put the device in the fridge, have it read the temperature (by adding a temperature sensor), and post it by wifi to a remote web site.
However, I have 2 issues:
1/ How would you advise to power the device? I don't want to have a cable go from the inside of my fridge to an external plug (bad for isolation + ugly). Use batteries? How long will they last (especially as it's "cold" in a fridge)? I can't burden myself to charge the batteries every day even every week,once every 2 weeks or per month would be acceptable.
2/ Do I need an Arduino board besides the ESP8266 to collect the temperature and send the data? I am a n00b for ESP8266...

Thanks
Axelle

1. use 2x - 4x Panasonic Eneloop R6/AA 2000mAh BK-3MCCE + step up/down ( in isolation
-20 C
2. No ! use google ds18b20 esp8266
P.S.
if you want to protect your food check the electricity in your home
UPS -> RS232 -> ... sms

axellec wrote:I'd put the device in the fridge, have it read the temperature (by adding a temperature sensor), and post it by wifi to a remote web site.

The fridge is not a faraday cage?

How I would do it:

I will note I have modified my fridge already using different lighting and it has been working for quite some time I will warn I am not using any of the correct IP66-67 parts for my modification but it does work and to the best of my knowledge it is safe although there is potential for a short I suppose the short will NOT occur without your knowledge that it has occurred if done in this manner the reason being I use the lamp socket in the fridge which is already connected to a switch which kills the power to the device unless the door is open. Why I did this after looking at the nice lighting in the new fridge's they have for sale my other half was in awww she really loved the new fridges for two reasons the lighting was nice there was light on every shelf and the freezer was on the bottom here we have an older fridge that works great and I cant see parting with 1000+ dollars for a fridge when we just purchased this one used and it works just fine thus there was a a thought I could redo the lighting and at least meet half of her expectations on the cheap! The result it worked rather well! I even love the upgrade.

In your case you will not have to worry at all:
What you need:

A water proof temp sensor
A drill bit 1/4"
A 5v 2A power adapter
An empty socket or power strip next to your fridge.
A nodemcu loaded with ESP Basic
Some wire in case you need it.

What you do first test your temp sensor figure out how it works and how to work it hooking it up to the correct pins and running code etc...

Next in the refridge gasket drill a hole with door on fridge closed.

Fish wires from temp sensor through the hole so they com out of the fridge on the hinge side and mount in a manner where when the door is all the way open or all the way closed it does not pull on the wire.

Fill hole with silicone once mounted and let set. Optionally tape over the silicone and gasket as well to ensure if silicone were to ever come lose you would not be losing any cool air.

Next using a chip clips with magnets or some tape mount your wiring and nodemcu on the fridge in a manner that is safe and looks decent. And go to town and have fun!