Inside the LW301
Yesterday I wrote about my hunt with the Wireshark to discover the secrets of the Oregon Scientific LW301 weather station. I got somehow stuck by the behavior of this little bugger. Chatting UDP and TCP like a computer but no real server inside. It made me curious.
When I took my Philipps screwdriver to open the blackbox, my bodyguard called “Butch” in her family, said NO. Do not destroy your little weather station. But already as a kid, if somebody said DON’T, I immediately got challenged and I translated this DON’T into an imperative DO! Today I can tell you, this behavior didn’t make my life easy, but it made it extremely interesting.
Lots of words. Let’s do it:
The screws of such boxes are usually hidden either under the label or under the rubber pads. The Oregon Scientific LW301’s screws are under the rubbers. Only loosen 4 screws and box falls open. It is a real lightweight with less than 100 grams.
If you are just a bit in hardware, you see in the top row from left to right: the power supply socket, an RJ45 network socket, the rest switch and 2 USB sockets. That’s what you also can see from outside.
The heart of the device is the black square with the blue and orange streaks. It is a Microchip PIC18F97J60 micro-controller. This black square does the whole job. All the other elements are there to help. For example the other big black rectangle, the H1601CG is a integrated transformer for the network communication. Dumb and passive it adapts impedance and voltage.
Let’s focus on the Microchip PIC18F97J60 micro-controller. There is a lot of information available on the manufacturer’s website. There are huge software libraries and tools available.
I had not yet the time to read everything. As we say here in the Philippines – tomorrow maybe. 😆