I want to use raspberry pi for a vehicle park project. The Raspberry will stay in a metal box and it will never power off. The metal box is waterproof but its in middle of a empty area so it will get really warm under sun and really cold at the winter.
So can I use raspberry pi for a project like this? Can someone give me idea?
I've run several Raspberry Pi's outdoors in my CA garden, which reached 100F on some days. Your project is definitely feasible, but it will take a surprising amount of supporting infrastructure.
Software: given the temperature variations, you should reboot the Raspberry Pi frequently to reset it to a known state. I've had Raspberry Pis drop off WiFi even though other Pi software kept going.
Temperature: Insulation is a primary concern and you can use thin, reflective foam insulation to good advantage. Also house the Raspberry Pi in a shaded location next to a large thermal mass that can help maintain acceptable temperatures. E.g., the air can be 100F but the concrete pillar in the shade is no doubt cooler. You can even bury your Pi enclosure in the ground. If you're lucky, your outdoor location may not need an active cooling solution.
Water: It rains it pours--zap dead Pi. Find a good weatherproof enclosure and verify that it works with a garden hose before deploying it.
Power: providing remote power to the Raspberry Pi is easily done with a solar panel that recharges a 12V lead-acid battery (yes and you need to keep that cool and dry as well!). The NEC has guidelines for voltages in applications subject to wet contact. 12V is fine. 24V is not. Use a DC-to-DC buck converter to feed your Pi.
Wiring: use weatherproof cables, connectors and housings. UV and rain are your enemies.
MadMax: it's outside. Vandalism and physical security are considerations.
All THAT for a wee little Pi? Yes.
As stated in the Pi FAQ, the board's LAN chip is rated between 0 and 70°C, and the SoC is rated from -40 to 85°C. Within these thresholds, the manufacturers specify that the components should work as expected.
Note that doesn't mean the board won't work outside of those temperatures; it simply means the manufacturers provide no guarantees about the Pi outside of these temperature ranges.
In reality, it's not a case of ensuring the outside temperature is between 0 and 70°C, though. The Pi will obviously run a little hotter than its environment (particularly the SoC), depending on its load. There is some discussion here about ambient temperature limits for the Pi, which doesn't really reach a conclusion. I suspect it's a more complex equation including air temperature, the humidity, amount of solar radiation absorbed, and so forth. Perhaps you can benchmark it to find out.
Alternatively, you could look into cooling (passive or active) for the Pi to use in the summer months. In the winter, perhaps you could just deliberately load the Pi to get its processor warm. Once again, testing your configuration would be worthwhile. If the container is airtight then your airflow (and hence convection cooling) is probably more limited.
