Hello guys,

I am planning to build a weather station as an electronics project. It is supposed to be a couple sensors (temperature, humidity, air quality for example) connected to a microcontroller (probably via I²C, because I’m currently interested in that and picked this project as an excuse to do something with it), and a basic LCD display to show the current data.

For this I want a small microcontroller that can collect the stats from the sensors and show them on the screen, so nothing too fancy. I want to actually deploy this on my balcony, so I don’t wanna sacrifice a Pi or something along those lines. Ideally something with a sleep mode so I can run it off a button cell. In order to use I²C and an LCD screen I would need around 9-13 pins, depending on the LCD. Plus some additional pins for buttons, means something with at least 16 GPIO pins would be desirable.

I was eyeing out something from the ATtiny family. Ideally it would be a through-hole-mounted chip as I want to use it on a breadboard first (and probably permanently). The only DIP chips are fairly old tho so I’m not sure if they’re easy to use nowadays. We used an ATtiny461A in university and had to program it via a Windows XP VM, which is an experience I would not like to relive.

I’m not afraid to get my hands dirty writing raw C code without an stdlib.

While the WiFi functionality of the ESP32 is appealing, I don’t know if I want to condemn one of them to a life on the balcony. I would rather use them for one-off projects instead and use something simpler for a long-term deployment.

The following are some ideas I have that I might want to add to my project later, but they’re just optional features and I don’t necessarily pick the microcontroller based on them:

  • Tracking/Logging sensor data over time, e.g. hourly. This would require some fairly accurate timing in order not to drift
  • Networking, so I can access the data via my local network

If there exist microcontrollers that fit my criteria I’d be happy to hear about them! I’m not an absolute beginner to electronics, but I’ve never shopped for microcontrollers before.

  • Lauchmelder@feddit.orgOPEnglish
    2·
    3 days ago

    Yeah, I think I’m gonna ignore networking for now. I’ll have a look at your recommendation, thank you!

    • Dave.@aussie.zoneEnglish
      3·
      3 days ago

      Regarding wifi and power draw, you could always do batch uploading of data to another server at something like a 1:10 ratio, or upload only when there’s a change of more than 1 degree or similar.

      There are some low power deep sleep esp32 boards out there that can do like 3-6 months on a couple of AA batteries. A lot of power draw comes from hanging around on wifi doing dhcp, so having fixed addresses can cut down power usage considerably.

      Even without using the wifi side of things the esp32 boards come with lots of IO , plenty of drivers for various devices, and a reasonable in-house (i.e. not Arduino) development environment so I’d be leaning in that direction.

      You could also look at Sharp’s memory LCD as opposed to normal LCD, as that’s extremely low power without the fiddlyness of e-ink screens.