For as long as I can remember I've been interested in the weather, and a number of years ago I acquired an old Z80-based custom data logging system. It wasn't too suitable for what I wanted, but it set me off on something I'm not sure I'll ever finish.
I want to create a weather station with a number of fairly standard sensors:
- Barometric pressure
- Light levels
- Wind speed and direction
- Anything else I think of later...
When I first considered this seriously, I was planning to use a Motorola 68HC08 microcontroller featuring built-in Flash, built in ADC and various other useful peripherals. However, this device had a limited amount of RAM which made some of my more silly ideas impossible.
Currently I'm planning to use a TiniARM module from New Micros, which features 128K of Flash, 64K of RAM and the ability to run at up to 60MHz. Currently I'm planning on writing my own OS, for the sake of experimentation with various OS techniques on a less complex platform than the standard PC, of which I plan to implement at least the following features:
- MMC/SD card support (simple, as they and the MCU support SPI and are both 3.3V)
- TCP/IP networking, using PPP probably
- Ability to load arbitrary binaries and run them from e.g. MMC card
- File system support (e.g. internal ROM fs, FAT32)
- Drivers for my weather sensors
- Utility to actually operate the basic weather station functions ;)
I've also been considering using wireless transceivers and solar panels to make the unit entirely wireless, but I'm not sure how well it'd work...