# Temperatures in Pizzeria freezers 🥶

**URL:** <https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041>\
**Category:** General\
**Created:** [13 September 2025 18:11 UTC](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041 "2025-09-13T18:11:48Z")\
**Posts on this page:** 10\
**Page:** 3

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**Author:** ![PizzaProgram](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/pizzaprogram/32/19431_2.png) [@PizzaProgram](https://discourse.nodered.org/u/PizzaProgram)\
**Post date:** [17 September 2025 08:48 UTC](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041/42 "2025-09-17T08:48:51Z")

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> [@Colin](#):
>
> The cable is thinner than the usual DS18B20 waterproof probe, at 3mm. It would still need **a 7mm hole** to feed the sensor through if you were using a drilled hole.

Thank you very much for the details 🙂

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**Author:** ![PizzaProgram](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/pizzaprogram/32/19431_2.png) [@PizzaProgram](https://discourse.nodered.org/u/PizzaProgram)\
**Post date:** [17 September 2025 09:25 UTC](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041/43 "2025-09-17T09:25:02Z")

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@pconroy328  
Thank You, yes I wrote about this possibility [at the beginning](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041/12) of this topic.  
I liked the idea that you just "drop into" a freezer and the work is done.  
But I was afraid that -40°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)](https://shop.pimoroni.com/products/sonoff-waterproof-zigbee-lcd-smart-thermometer-probe-version?variant=55650795553147)

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**Author:** ![PizzaProgram](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/pizzaprogram/32/19431_2.png) [@PizzaProgram](https://discourse.nodered.org/u/PizzaProgram)\
**Post date:** [17 September 2025 09:27 UTC](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041/44 "2025-09-17T09:27:22Z")

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> [@pconroy328](#):
>
> RTL-SDR dongle

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?

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**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [17 September 2025 12:32 UTC](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041/45 "2025-09-17T12:32:13Z")

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For Zigbee I use a [Sonoff Zigbee 3.0 USB Dongle Plus](https://shop.pimoroni.com/products/sonoff-zigbee-3-0-usb-dongle-plus?variant=54923349098875) which has about the same range as a good wifi router.

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**Author:** ![pconroy328](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/pconroy328/32/82550_2.png) [@pconroy328](https://discourse.nodered.org/u/pconroy328)\
**Post date:** [17 September 2025 16:09 UTC](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041/46 "2025-09-17T16:09:02Z")

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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

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**Author:** ![rz7k9l](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rz7k9l/32/77811_2.png) [@rz7k9l](https://discourse.nodered.org/u/rz7k9l)\
**Post date:** [17 September 2025 18:24 UTC](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041/47 "2025-09-17T18:24:16Z")

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check out Ruuvi sensors  
[How cold freezer or freezer should be? Instructions to Freezer Temperature Adjustment. - Ruuvi](https://ruuvi.com/freezer/#product-8)

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**Author:** ![Alacritous](https://avatars.discourse-cdn.com/v4/letter/a/9fc29f/32.png) [@Alacritous](https://discourse.nodered.org/u/Alacritous)\
**Post date:** [18 September 2025 21:10 UTC](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041/48 "2025-09-18T21:10:30Z")

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These threads are pretty useless as everyone vomits out their preferred way of addressing whatever problem/issue the OP asks about..

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**Author:** ![Paul-Reed](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/paul-reed/32/66906_2.png) [@Paul-Reed](https://discourse.nodered.org/u/Paul-Reed)\
**Post date:** [18 September 2025 21:23 UTC](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041/49 "2025-09-18T21:23:35Z")

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> [@Alacritous](#):
>
> These threads are pretty useless

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.

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**Author:** ![E1cid](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/e1cid/32/77971_2.png) [@E1cid](https://discourse.nodered.org/u/E1cid)\
**Post date:** [19 September 2025 08:24 UTC](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041/50 "2025-09-19T08:24:25Z")

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@Alacritous

> [@Alacritous](#):
>
> These threads are pretty useless as everyone vomits out their preferred way of addressing whatever problem/issue the OP asks about..

Which is what the OP asked for , suggestions.

> [@PizzaProgram](#):
>
> I’d like to ask for any suggestions, what:
> 
> - devices,
> - nodes  
> work fine with node-red ?

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**Author:** ![alfort57](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/alfort57/32/65161_2.png) [@alfort57](https://discourse.nodered.org/u/alfort57)\
**Post date:** [24 September 2025 14:42 UTC](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041/51 "2025-09-24T14:42:37Z")

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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

[Previous page](https://discourse.nodered.org/t/temperatures-in-pizzeria-freezers/99041.md?page=2)