Hi, I don't know if this is the right section to post this(sorry if not) , im working on a project that sniffs current wifi networks in an area. It is equipped with an esp8266 as the sniffer. It is mounted on a robot that is controlled via wifi. The sniffer needs to be housed in a case but I don't know which material to use for it. It is required to be fire-proof (it needs to survive passing through a fire) Which material do I use? Do I make a full enclosure? Will the signal be disrupted to the point that it will not be functional?
You can't use conductive material (metal) which would block signals. Glass, most ceramics, or mineral wool insulation should protect the transceiver from fire.
I see, but doesn't that block or disrupt any signal?
Every material will attenuate your signal but not to the same level. Metals are really good at stopping/reflecting electromagnetic waves. For every other material the frequency (WiFi ~2.4GHz) will be a deciding factor how much attenuation you get. Whether this will affect your application depends on what is called the link budget.
The transmitter has a certain power level that is used to send the signal. This is usually defined by government regulations and electrical power budget e.g. battery size
The receiver has a certain sensitivity at which it can still receive and decode the signal. (some are more sensitive then others).
This gives you the link budget. Usually the unit dB is used for that.
The link budget can be improved by good antennas.
And it will be "used" by distance and materials trough which the signal has to travel.
As johnwasser wrote ceramic, fiberglass and mineral wool enclosures should be able to protect your electronics against heat. Of course you will need to do some test regarding material thickness vs heat exposure time.
And you will need to do some testing regarding the attenuation.
If you have difficulties in air because your distance is far it will get worse when you use an enclosure. Then you will need to compensate this for instance by better antenna. But If you have the second Wifi point close by, you might not need to worry.
"It is mounted on a robot that is controlled via wifi."
How will you heat protect that? You might try forming an enclosure, round or square, out of fiberglass cloth, then fill the inside with fiberglass insulation with your wifi stuff inside the insulation. A trip to the home improvement store could get you started. Another insulating material might be perlite beads from the garden center. All that might be needed outside the heat box is a metal wire antenna, the rest inside.
That is what we initially planned, we were concerned with the strenght and the ability of the sniffer to locate and detect nearby networks if we do make it enclosed. Also is there any metal antenna made for esp8266?
redlop:
That is what we initially planned, we were concerned with the strenght and the ability of the sniffer to locate and detect nearby networks if we do make it enclosed. Also is there any metal antenna made for esp8266?
You might get one of the can openers that goes around the side of a can top to cut the top off. With this type of cut, the top can be fitted back on as a lid. Then the can could be the container housing with the radio equipment inside surrounded by the perlite beads and an antenna protruding thru a hole in the can lid. You would probably have to make your own antenna.