Hello, I'm putting my ESP32 in a metal housing. I know for a fact that metal will limit or block all signals like wifi and bluetooth. But I was curious If the ESP32 is strong enough to get a little bluetooth signal out to a device that is close to 2 feet away. Has anyone ever tested something like this before in the community?
I know it be better in a plastic housing but this is going in alarm system and just going to program it while the door it closed because most of the time it's screwed on and takes 8 screws just to open the door. My ESP32 doesn't have an external antenna. But I know how to cut the trace nad put on an external antenna. I will do that in time. I just wanted to try this out first and see what happens on my alarm system.
But I was curious before I do it i wanted to ask the community first.
I didn't try it yet. But I have googled a lot of pages. and a lot of misleading information as well as good information. I was just curious that's all before I try it soon.
It may or it may not work, you'll have to try it. I tried using a cookie tin as a Faraday cage for a test and it didn't work so well. My test was with a BLE sensor; since ESP32 Wi-Fi is using more power, it's more likely to get more signal out.
There is a lot of naive notions of what a Faraday cage is, how effective it is and how easy it is to make.
In actual practice putting something in a metal enclosure is not a very good way of trying to implement a Faraday cage. It will often cause radiation at much higher frequencies.
This is because any breaks in the metalwork will act as resonant slot antennas. So gaps where the signal and power wires come in will radiate.
Also an enclosure has to have some way to get the parts into it in the first place. This, whiles it might look a good fit, seldom is. To get round this all sorts of things are sold, like metal fingers, and fine metal mesh. A look at any serious site giving RFI advice will have examples of these add ons.
Hello all, I'm sorry for the late respond back. I couldn't test anything because I ended up in the ER room this morning. I got some kind of flu or bug going around. As soon as I'm feeling a little better I will try everything out. Thank you for all the help and support on this crazy project idea. I will post an update in a day or two.
Using the cookie tin as a Faraday cage didn't work well. TBH, I don't even remember why I was doing it. I think I might have been trying to test my software's response to an unreliable signal. If so, I probably ended up just using my body as a shield.
Also: full shielding is only reached with a zero resistance cage. Maybe you should have used a massive enclosure of gold (say 5mm thick) instead of your tin can...
Hello all thank you for the help and. I have learned a lot about esp and metal housing. I got outbid the hospital and tested a little feeling better so I tried it and it seems I can get a Bluetooth signal. I don’t have WiFi. I’m going to in time setup a Ethernet wire. I just not feeling to well. I thought I can go to Bluetooth to receive some status information. But it looks like I would need to do Ethernet for the long haul. Again thank you all for the help.
In a few days I will do an update to this post and show everyone what I’m doing.
Some metals are more highly conductive than others. Copper, silver, aluminum, gold, steel, and brass are common conductors of electricity. The most highly conductive metals are silver, copper, and gold.
But that's not what OP is asking.
I think he just wants to use a cheap metal enclosure that lets a bit of 2.4Ghz through.
A tin box sounds fine. Just try it.
Leo..