Jakub Smejkal, Martin Hubáček, Lukáš Fabik, Alan Fabik

Published June 25, 2019 © CC BY-SA

HARDWARIO IoT Kit Smart Fridge Monitor

Overfreezing you fridge is not good for your food and power saving, with this fridge monitor, you will always know the temperature in there.

BeginnerFull instructions provided1 hour1,838

Things used in this project

Hardware components

HARDWARIO Climate Monitor Kit

HARDWARIO Radio Dongle

Software apps and online services

HARDWARIO Playground

Blynk

Node-RED

Story

My roommate sometimes leaves the door to the fridge open, so the fridge has big power consumption and it makes the frosting. I put my Smart Fridge Monitor in there so I always know about the temperature and also get a notification if he leaves it open for too long so I can close it.

I used HARDWARIO IoT Kit technology, they already have firmware that is suited for this solution, so I just customized the flow in the Node-RED and it was all set up. My device runs just on two AAA batteries, it can work for up to two years.

1. Build Hardware

Connect Core Module with your Mini Battery Module, then connect Climate Module to it.

If you have trouble assembling the device you can watch the video below for complete guide. But it should be simple for anyone.

1 / 3

For more information about all the modules you can visit Documentation.

2. Flash firmware

Download HARDWARIO Playground.
If you bought the ClimateMonitor Kit you will receive the Core Module with the firmware on it.
Otherwise you can see documentation page on how to flash the firmware with HARDWARIO Playground.
You will need the bcf-radio-climate-monitor firmware for this project.

Here you just click Flash firmware and wait. After it is done, unplug the Core Module from the computer and you are ready to continue.

3. Pair the Core Module

You need to pair the Core module with the Radio dongle that you are using, follow the instructions below to see how it is done.

The same thing will go if you are using a Raspberry Pi as a server, just access the Raspberry through the IP address instead of the Playground

Connect your USB Radio Dongle to your computer.
Open HARDWARIO Playground

Click Start Pairing the LED on the dongle should start blinking
Connect the device that you want to pair into your computer or insert the batteries.
Wait for the device to appear in the table
It should add the device with the Alias: climate-monitor:0
Click Stop Pairing

After you did all this you can unplug the device from the computer and insert the batteries, it will run on them without a problem. Next steps will be done on the computer, so you can leave the device and focus on the Playground.

4. Import function

Open Node-RED in Playground (Functions tab) or on your Raspberry Pi and import this simple function from the Attachements. Just copy everything, go to Menu -> Import -> Clipboard and paste it there.

After Import hit Deploy in the top right corner to upload the change.

In this function you can change the message that will appear when the doors are open for too long. You can also change the time before you are notified that they are still open. Go to Open doors checker function and change the marked value. Time will be the value times 5 seconds.

Function view

5. Blynk integration

This project is ready for Blynk integration. How to set up Blynk with your HARDWARIO Playground is described in this guide.

Follow the guide if you want to make your own blynk app. If you want to use the one specified for this project in the Blynk app click this Icon and scan the QR code bellow.

QR code for blynk application

In this blynk application, you see the temperature in your fridge and get a notification when the fridge is opened for too long, also if the led is on the fridge is still open.

6. Insert your device to the fridge

Just put your device into the fridge and let the temperature settle down, after a while you will see the correct numbers.

Summary

If you have everything done you can get one of the 3D printed enclosures.

You can also put this device into the freezer, it can handle sub-zero temperatures.

I will be happy for any suggestions or ideas about this project.

Feel free to ask and I will try to answer any question.

Visit HARDWARIO page on hackster.io for more interesting projects or go directly to their website
Go to HARDWARIO documentation to learn more about their modules and other possibilities of the platform.
Try more firmware from HARDWARIO Playground or write your own, it is easy to start.
Because everything is Open source you can get all firmware on GitHub, get some inspiration and try to make your own applications.
Get your own HARDWARIO Hub to replace your computer in this project so you have always access to your applications.
Check out more applications that can be used with HARDWARIO IoT Kit in Integrations section.

NODE-Red function

[{"id":"75a58308.8012fc","type":"tab","label":"Fridge Monitor","disabled":false,"info":""},{"id":"17a6ebe3.d9e214","type":"mqtt in","z":"75a58308.8012fc","name":"","topic":"node/climate-monitor:0/thermometer/0:0/temperature","qos":"2","broker":"e649966c.8c2af8","x":230,"y":260,"wires":[["3e232099.53286","c0e10e95.0d9e1"]]},{"id":"3e232099.53286","type":"blynk-ws-out-write","z":"75a58308.8012fc","name":"","pin":"1","pinmode":0,"client":"26f45542.cf788a","x":980,"y":260,"wires":[]},{"id":"6287986.9c02568","type":"mqtt in","z":"75a58308.8012fc","name":"","topic":"node/climate-monitor:0/lux-meter/0:0/illuminance","qos":"2","broker":"e649966c.8c2af8","x":220,"y":300,"wires":[["fd9eee65.3adb4"]]},{"id":"f8117dfc.392ef","type":"blynk-ws-out-write","z":"75a58308.8012fc","name":"","pin":"2","pinmode":0,"client":"26f45542.cf788a","x":980,"y":300,"wires":[]},{"id":"fd9eee65.3adb4","type":"function","z":"75a58308.8012fc","name":"Open doors checker","func":"var value=flow.get('iluminance') || 0;\n\nif(msg.payload > 20)\n{\n    value++;\n    flow.set('iluminance', value)\n}\nelse if(msg.payload < 20)\n{\n    value = 0;\n    flow.set('iluminance', value)\n    msg.payload = 0;\n    return msg\n}\nif((value % 5) === 0)\n{\n    flow.set('iluminance', value);\n    msg.payload = 255\n    return msg\n}\n","outputs":1,"noerr":0,"x":580,"y":300,"wires":[["f8117dfc.392ef","1e0ed309.4cdd9d"]]},{"id":"e362bcd1.3209","type":"blynk-ws-out-notify","z":"75a58308.8012fc","name":"","client":"26f45542.cf788a","queue":false,"rate":5,"x":950,"y":340,"wires":[]},{"id":"1e0ed309.4cdd9d","type":"function","z":"75a58308.8012fc","name":"Message","func":"if(msg.payload == 255)\n{\n    msg.payload = \"Fridge doors are open for too long\";\n    return msg;\n}","outputs":1,"noerr":0,"x":800,"y":340,"wires":[["e362bcd1.3209"]]},{"id":"c0e10e95.0d9e1","type":"ui_gauge","z":"75a58308.8012fc","name":"","group":"4a6d0465.baa43c","order":0,"width":0,"height":0,"gtype":"gage","title":"gauge","label":"units","format":"{{value}}","min":"-10","max":"20","colors":["#00dae6","#ffa620","#ca3838"],"seg1":"0","seg2":"10","x":590,"y":200,"wires":[]},{"id":"e649966c.8c2af8","type":"mqtt-broker","z":"","name":"","broker":"127.0.0.1","port":"1883","clientid":"","usetls":false,"compatmode":true,"keepalive":"60","cleansession":true,"birthTopic":"","birthQos":"0","birthPayload":"","closeTopic":"","closeQos":"0","closePayload":"","willTopic":"","willQos":"0","willPayload":""},{"id":"26f45542.cf788a","type":"blynk-ws-client","z":"","name":"Fridge Monitor","path":"ws://127.0.0.1:8080/websockets","key":"886ca14547c1497d9e894f8583645094","dbg_all":false,"dbg_read":false,"dbg_write":false,"dbg_notify":false,"dbg_mail":false,"dbg_prop":false,"dbg_sync":false,"dbg_bridge":false,"dbg_low":false,"dbg_pins":"","multi_cmd":false,"proxy_type":"no","proxy_url":""},{"id":"4a6d0465.baa43c","type":"ui_group","z":"","name":"Fridge Monitor","tab":"c4b88390.6daab","disp":true,"width":"6","collapse":false},{"id":"c4b88390.6daab","type":"ui_tab","z":"","name":"Fridge Monitor","icon":"dashboard"}]

HARDWARIO IoT Kit Smart Fridge Monitor