I want to share a project with you that I was working on last year. For my home I wanted to have an device that measures Temperature, Humidity and Pressure and publishes the data to my local server. And I really liked the Netatmo solution but it was a little bit too expensive for me so I decided to make something like a clone. Or just simply a Weather Station inspired by the Netatmo devices.
So I started with a list of key features the weather station should have:
- Small dimensions
- Temperature / Humidity / Pressure and (Battery)-Power Sensor
- Battery or wired power Connection (with Battery power at least 2 month “lifetime”)
- Low Power consumption
- Remote controlled measurement interval (15, 30, 60 minutes)
- Easy changeable (if Photon dies or whatever)
- Library for Sensors should already exist
- Nice look/housing
- Easy to add new Sensors
And what I realized early is that I needed a custom printed PCB. So I made a circuit design (I’m an Engineer, so that and soldering was not a problem) and selected the Sensors for the project.
- Temperature / Humidity: SHT21 (±0,3 K and ±2 %rH)
- Pressure: BMP085 (±2%)
- Power: Just a regular Voltage divider
Stuff like remote control of the measurement interval, low power and publish to local server are all made in the application. So I wrote one, where the communication is made via MQTT and another one with HTTP. (Had problems with MQTT, that’s why the HTTP).
For the battery power I got a battery holder that holds 4 AA batteries. With a protective resistor I can power my Photon and the Sensors with this “package”. With these 4AA the device works for 2-5 Months (depending on the measurement interval).
Now I get measurements from my different rooms, get a notification when I need to charge the batteries etc. etc…and I think it looks pretty good for a diy project.
So…that’s basically it. By the way, if someone what a PCB (with soldered components or without), just let me know. I have some left.
Hope you like it
PS: Sorry for the language, I’m not a native speaker.