Placeholder Image

Subtitles section Play video

  • From the dawn of mankind...

  • ...driven by curiosity and aspiration...

  • ...men urged for a device...

  • ...to log air pressure?...

  • ...using a microcontroller?

  • WHAT THE..?!

  • I'M OUTTA HERE!

  • Hey wait...

  • ...okay.

  • Today we will create a simple temperature, pressure and altitude logger.

  • This device should be really easy to build. So, hang on!

  • We will use three component blocks:

  • The main driver is the WeMos microcontroller

  • It's based on the esp8266, which has built-in Wi-Fi capabilities.

  • You can get one delivered for under $3.

  • The pressure sensor is available as this shield

  • It provides precise temperature and air pressure measurements.

  • The output will be done on this OLED shield.

  • To have enough juice while logging we will power it from this power bank.

  • You can find the links to the parts in the description.

  • The only soldering needed is to attach the pin headers.

  • Anyone can do this!

  • The altitude is calculated from the air pressure.

  • This is rather an approximation:

  • The higher the altitude, the lower the air pressure.

  • The current altitude is estimated from 1000hPa at sea level

  • and the current measured pressure.

  • This is dependent on the weather.

  • It will overestimate the altitude at bad weather

  • and underestimate it at good weather.

  • But more on this when we build a weather station.

  • For the software part of the microcontroller we will be using the arduino IDE this time.

  • You can download my sketch from github.

  • The link is in the description.

  • The most of the work is done by some libraries.

  • First of all you need to add the esp8266 support, if you haven't yet.

  • Check out my other tutorials for this.

  • Then, we need also the following libraries:

  • Adafruit MQTT, Sparkfun micro OLED, Adafruit BMP085

  • Install all of them and you are good to go.

  • There are some settings to make in the code.

  • First of all, we need some access point credentials.

  • Since we will be logging the values using MQTT we have to set up the MQTT server here.

  • I am using Adafruit IO.

  • You have to enter your username and your secret API key here.

  • If you want to change the feed names you can do this here.

  • This delay defines at which rate values will be sent to the MQTT server.

  • Ok, you can also switch to Imperial values

  • but please don't crash another space probe.

  • My code will calculate the average values from each time span.

  • The Sparkfun OLED library seems to be the only one,

  • which supports the OLED screen with 48 pixel rows without any code changes.

  • Let's flash it!

  • To log the values outdoors I'm using my smart phone as an access point.

  • On Android this can be done using a mobile hotspot.

  • I'm using the same credentials as the ones from my lab so I don't need to reconfigure it.

  • But you could also add additional access points in the code like this.

  • Let's test it!

  • Okay you can clearly see a pressure difference here,

  • but that's not good enough.

  • Okay, I think we arrived at the place where to test it.

  • And this is what it shows.

  • The altitude in the mountains was off by around 5%.

  • The logging works also nice.

  • I can see a nice graph on Adafruit IO.

  • The only thing missing is the case. So, let's create one!

  • Good news! I'm doing YouTube full-time now.

  • So that means one video a week!

  • To celebrate it I will give away three of those here on YouTube

  • and two additional on my Patreon page.

  • You can get additional content there

  • and also get your name displayed in my videos like these supporters here.

  • To get one of these here simply write a comment containing the hashtag #giveaway and pick a color.

  • You also need to be a subscriber.

  • If you have missed this giveaway simply subscribe to get a chance next time.

  • See you next week, bye!

From the dawn of mankind...

Subtitles and vocabulary

Click the word to look it up Click the word to find further inforamtion about it