Building a Wireless Temperature Sensor with ESP8266 & Arduino

For my first video, I walk through building a wireless temperature sensor based on the ESP8266 chip - the hardware, some theory, and the code.
The code used in this clip is freely available here: github.com/and...
This is my first try at getting something like this together into a video, so constructive comments are appreciated!

[@vonrollveeg]

I'm 71. It does my soul good to see there are still bright creative people in the world. Good work. I'm going to play around with this.

[@bitschips]

Go for it and build it!!

[@ilyushin78]

Are you alive?

[@peterharris7682]

A very useful video Andrew. I used it as the basis for a remote temperature sensor but with a few changes Firstly I needed an external antenna and couldn't find a suitable 8266 with a uFL antenna socket so I used an ESP32 which worked fine Secondly I used a DS18B20 temperature sensor instead of your thermistor which was easier as it didn't need complex calibration and calculations Thirdly, I needed to extend the battery life. I found even deep sleep mode wasn't good enough as the board is still drawing 6.5mA when asleep. I therefore ended up using a TPL5110 Nano Power Timer (the Sparkfun version) which works a treat and only draws 35nA of power when sleeping. It was dead easy to implement and since the main board effectively does a cold boot each time it is woken up I don't get the occasional lock-ups I got using the ESP32 deep sleep mode. Once again thank you Peter

[@TysonClugg]

Great stuff Andrew! I have one suggestion. Instead of placing the voltage divider between Vcc and ground, place it between an available output pin and ground. In this way, you can switch that part of the circuit off to both save power, and prevent heating of the thermister which will skew your readings. Activate the output pin, wait a short moment for the circuit to quiesce, take the voltage reading, and deactivate the output pin again.

[@AndrewGodwin]

Yes, I did that in a previous revision, I'm not sure why I didn't here. Thanks for the tip!

[@TeamRiceUSA]

Tyson Clugg nice commits on Mr. Godwin wifi temp

[@adityatyagi1869]

Excellent video, Andrew. My embedded systems project team used your video to learn how to wire our temperature sensor to our ESP8266. Keep up the good work! Strong presentation skills with intuitive explanations and top-notch video editing. Consider making more videos.

[@DavidJJJ]

Great project, I’ve done the same thing except I’m using an esp32 and sending the data directly to MySQL (and then reading it with grafana from there). I have 5 sensors around the house and I use the MAC address to distinguish between the sensors in the database. Works quite well. I’m also doing the deep sleep thing and have a 5 minute timeout between temperature reads. I’m also using an stm based temp/humidity sensor.

[@sadistfcfm]

Wow, i knew i know you before... what a coincidence being working on both ESP8266 and django channels! Great work man.

[@RaiyanKamal]

Hi Andrew thanks for this tutorial. I often see ESP32 but this is the first time I heard of ESP8266. If I may, I'd like to request a video review comparing these two components.

[@Gerry2xs]

Thanks Andrew. Like your video, nicely explained.

[@SaurabhRastogiRC]

Very good video ...... Andrew. Looking for more from you.

[@bitschips]

Nice video, very good very well explained and interesting! Thanks for time.

[@0nedon]

well done video and well explained, really helpful to help me decide on my next project, thank you Andrew. - Would i be able to use the ESP32 in place of the ESP8266?

[@steve42lawson]

0:17 "Only a _couple_ of the steps? What about the rest of the steps?!? Are you going to leave, a quivering mess, while you cackle maniacally over my smallness?!?" Sorry, just messing with you. Great video! It gave me all I needed to proceed with my own project. I've always wondered how you pass data using POST and GET. The documentation I found on this lacked examples, making the whole thing rather vague, for me. Your example cleared that all up, so thanks! One *Note* Though: At 13:13, why would you have the LED glow for the 10 second idle period, and extinguished for the short data acquisition period? Wouldn't you want that the other way around, so there's not such a load on the battery?

[@jseneque]

Awesome first video!!! Keep it going

[@Taylor-zq3qr]

Andrew. Love the video! Can you update your description to include a shopping list and make a waterproof/resistant sensor?

[@mikeperry2561]

Very well explained!

[@dbrgn]

Nice video. You can also get an even simpler circuit by using a DS18B20 one-wire temperature sensor.

[@sausage5849]

Good job with this video. Great explanations too. Subbed!

[@nothingtoseehere5760]

Just brilliant! I wonder if you have tried putting it in a chest freezer and if it still connects? I am worried about the freezer insulation acting as a Faraday cage but don't have anything that I can control/test with...

[@dlseverns]

Really well done and thorough. Thank you!

[@ryandoyle9674]

Super helpful, thanks Andrew! Your video was comprehensively informative and clear ... as a newbie in this space, I really appreciate the completeness of your explanations. I was wondering about expanding this project to also track humidity and light for a fuller picture of the atmosphere. Any thoughts on how I might accomplish this? How might I add a photoresistor to this circuit? Could I swap the thermistor for a DHT11 and track both temperature and humidity with the same component? Am I thinking along the right track?

[@athief]

battery life given a full charge would have been very useful. How long does it last with that setup? 3 hours? 3 days?? 3 weeks???

[@1_HighDuke]

It's probably a very power-hungry setup. Measuring and transmitting every 10 seconds will eat up the battery in no-time. If you want longer battery life, first measure & transmit less often. And second, implement deep sleep so that you reduce consumption between polls.

Hi, can you put the parts list in the description. I’d like to try to build the same

[@MatthewPotter-m4k]

pls is there a list of parts to get im new and kinda lost

[@MrHandsomejackuk]

excellent project maybe worth lookig at a sonoff th10 as this has all the hardware built in it is mains powered but could be battery powered too

[@phil4000n]

very interesting. Couple of questions: never heard before of influxdb and grafana, do you mean to heavy to run the ESP8266 as a server? Do you have or now a good tuto, but sounds steep learning curve. I'm not getting if you found an advantage on using Adafruit Huzzah Feather ESP8266 over nodeMCUv2 Amica, can you comment. Excellent that you show the physical soldering, too rare on YTUBE.

[@ExopMan]

How would you update this build now using more modern/smaller components? Thank you!

[@rolocox100]

fantastic clear talk and video. would it be possible link a microwave radar sensor such as the RCWL-0516 and then output this via the ESP8266 to make a low cost remote motion sensor.

[@hackinblack7102]

very good video,very clear...but i cant help thinking it would be easier, and more accurate, if you used a 'smarter' sensor; either a linear output thermistor, or a temp to voltage converter IC; then you wouldn't need to measure anything (your temperature measurement AND you resistance measurement both introduce errors) most sensors give 10mV per degreeC and upto +/_1% accuracy. you could probably even use a normal IN4148 diode as a sensor; almost any PN junction shows a mV change with temperature.

[@leglessinoz]

Hack In Black or one could use an LMT01 digital sensor.

[@kollaattori2494]

Am I missing something? To my knowledge there is NO analog pin (A0) in ESP8266.

[@aquilax]

Nice and informative. I wonder how easy it will be to hijack the connection with second WiFi with the same SSID?

[@Brickkzz]

great video! subscribed!

[@gouravdabade]

what is the range ?

[@felixlaurencelle7016]

I loved that video! I was going to start that project but i have 0 knowledge about the software part. Do I need to install InfluxDB and Grafana on one of my computer? And do i name the "host" that computer IP Adress? Do you suggess an video to learn that process better? Thanks a lot in advance!

[@Dreathan]

I got same questions... Did you receive an answer?

[@mohammedzaman1937]

awesome! is it possible to control a led/relay remotely based on a set temperature on this one.

[@3vedinishit]

Hi Andrew.. is it possible to make contactless temperature sensor(like temp. gun) using ESP8266 ?

[@manojrjadhao]

Hi, Andrew, it is really nice introduction of wireless sensor. I am also working on same board. I have a question, is there a way where we can make the device use very less power from battery and let it lasts for more than 6 months? I am thinking making its size and cheaper.

[@AndrewGodwin]

The ESP8266 board has a deep sleep mode where you can save battery - you can make it sleep for intervals of up to 70 minutes, and then wake up and send a measurement. You could probably stretch it out to a few months of battery if you made the recording interval 5 minutes or so and used a couple of AAs.

[@manojrjadhao]

Hi, thanks for quick reply. Can you tell me, how much power will be required for a day if I keep the interval of 5 minutes? I am thinking of using this battery: www.amazon.in/Robu-Samsung-2600mAh-18650-Lithium/dp/B0765SL77F?tag=googinhydr18418-21&tag=googinkenshoo-21&ascsubtag=f1cf1053-27c4-4cda-8c82-682d058ea547

[@Ed19601]

Manoj Jadhav when you Google esp8266 deep sleep you will find the current use in deep sleep as well as the current use while making WiFi contact. Add to that the current flowing through the ntc. That gives you the amount of current over 5 minutes There are 12*24 periods of 5 min in a day

[@Electromaniaworld]

can you show to to setup plotting of that graps ?

[@mhamzahkhan]

Kind of off topic question... what stand are you using for your monitors? I am pretty sure I have the same desk as yours (ikea galant?) and I'm looking for a better monitor stand that I can use.

[@KM6VV]

Thanks for publishing! Where can I find ESP_thermometer? I've downloaded and looked in arduino-examples-master per your link below, but haven't been able to find it.

[@sodapop111]

can you specify the resistors and the type of thermistor you used? (basically the parts used in this video because it is vaguely said)

[@AndrewGodwin]

The thermistor is a 4K7 NTC type. The resistors are, I believe, 2kOhm on one side of the divider and 4.7kOhm on the other, standard carbon type.

[@ytbTheogr]

That's a very good project idea! Can you please tell me which version of influxdb did you use? I'm trying to write data to influx via http with arduino and i get "Method Not Allowed". Thanks

[@whatmust8146]

Thermistor is the way to go. You can get one for free from old battery pack particularly the Ryobi one. I have done a ton and never need to buy any thermistor. I build many thermistor base Arduino one with multiple reading of temp. I am doing IOT now with every thing if possible over wifi and web base. Reduce reuse recycle is way harder than to buy anything everything brand new. People choose the latter because the former is way harder and more work to do. I always choose the 3 R's because that is me. Reduce Reuse Recycle. Everyone needs to do their part by doing the R's!!!!!!

[@mikepickell8792]

Is there a bluetooth type?

[@servant74]

Question: Could I put say, 3 thermistors on one of these devices? I need each away at 1 then 2 and 3 meters from the ESP8266?

[@deDutchRooster]

Parts list?

[@jpthedelawarebeeman6239]

How do I get Fahrenheit and not Celsius ?

[@FoX84tac022]

Google how to convert Kelvin to Fahrenheit?

[@jpthedelawarebeeman6239]

Thanks I figured it out already !

[@etiennemp7100]

Hi ! What's the name of the graph interface that you use ?

[@paulwalker5294]

That was Grafana

[@dand8282]

does that send the password in the url in clear text? https is a pain w/8266...

[@AndrewGodwin]

It does - as you say, HTTPS is a pain. In my case it's only going over a local network, thankfully.

[@yvindmathiassen7617]

are there coming more videos like this? I liked it very much, I subbed you just in case :)

[@AndrewGodwin]

Hopefully! I have plans for the next one, need to find time to film it.

[@VoeViking]

Bit vague in the important stuff. If you really want to make a good video start at the beginning, first the earth cooled than the dinosaurs came, after that I installed this server in this manner using this and that...

[@Varunsharma014]

Andrew, I am designing a product on which I need someone with knowledge of electronics to help. Can you help me out? I can pay you fee for your services. Thank you.

[@thehomeschooldev6126]

#Thehomeschooldev #IoTEngineering

[@MrBobWareham]

I was most interested in the project until you used the adafuit hazzah being a very expensive product like all adafruit products so will not be following your video thanks!!

[@Ed19601]

Bob Wareham get a wemos D1 mini

[@bhekintanzi6761]

Parts list?