Thank you very much for the details 
@pconroy328
Thank You, yes I wrote about this possibility at the beginning of this topic.
I liked the idea that you just "drop into" a freezer and the work is done.
But I was afraid that -40Ā°C kills the 2 AA batteries too fast.
Also if the wireless signal is coming from inside an inox metallic box, the range will be too sort.
That's why we have switched to a "separate wired sensor" solution, like this:
Sonoff Waterproof Zigbee LCD Smart Thermometer (Probe Version)
Just asking, (because here at home I'd like to try this and put a device on my tree outside) :
Which Dongle did you use?
- where did you order from?
For Zigbee I use a Sonoff Zigbee 3.0 USB Dongle Plus which has about the same range as a good wifi router.
2 Likes
It's been a while, but I tried to avoid the clones and find a genuine RTL-SDR v3 dongle. I believe I bought it from Amazon. Yep - just checked. I bought it from Amazon back in 2021
check out Ruuvi sensors
How cold freezer or freezer should be? Instructions to Freezer Temperature Adjustment. - Ruuvi
3 Likes
These threads are pretty useless as everyone vomits out their preferred way of addressing whatever problem/issue the OP asks about..
Disagree!
Putting options forward enables @PizzaProgram to determine the best solution for him.
Sure, everybody has their own opinion, and many suggestions will be disregarded, but maybe someone has a solution which ticks all of the boxes.
5 Likes
Which is what the OP asked for , suggestions.
3 Likes
Temperatures on freezers
Hi, Just want to let you know that I did a similar project for a charity group.
They want an alarm system for there frig and freezers.
This was a very low budget (as close a s possible to $0)
Summary:
Sensors: Ds18b20 ss tip inserted in every freezers.
Cable routed trough doors or vent opening.
Multi drop cable using BDN cable, max 6 sensors per OneWire bus
ESP8266 in ABS box, can drive 3 oneWire bus (3.3V supply) powered using regular 5Vdc switching PS.
ESP8266 on proto board using terminal for one wire and 5 Vdc PS connections
Wifi connected link to Raspberry Pi running Node-red using MQTT.
Freezers were located on 2 differents story, so 2 ESP8266 were used.
Total device :16 plus 2 room temperature
Alarm messaages sent using email, 3 level in alarm since 45 minutes, 75 minutes and 360 minutes
This system is running since 2018
original system:
RaspberryPI 3
OS :Debian Stretch
Mosquitto MQTT
Le programme en node-red
Node-red: 0.18.4 extension UI
6 Likes
