3 ms·

At the cheap / DIY end, you might be surprised just how effective a metal toolbox is, with the paint filed off the seams around the lid, and some aluminum foil

At the cheap / DIY end, you might be surprised just how effective a metal toolbox is, with the paint filed off the seams around the lid, and some aluminum foil to help make connections / cover the gaps to the lid etc. We had this problem with a test station for Bluetooth Low Energy (BLE) devices in our factory. With over 250 visible BLE devices visible, the local Bluetooth stack would crash. With a USB Bluetooth module within the toolbox, and the device under test also in the toolbox, we could reliably get it to pick up just the one device, so long as the lid was closed and latched firmly. And then confirm with RSSI that you’re only seeing a very-nearby transmitter. :)

amelius 3y ago
If you think about it, it is a kind of ridiculous idea that you would need super-sensitive equipment to determine if some cheap device would interfere with the workings of some other relatively cheap device.
- mNovak 3y ago
  Do you need sensitive equipment to see if something is totally destroying performance? No. But arguably by definition, you need the ability to reliably measure at or below the noise floor in order to determine if some emitter is putting out interference that will raise the noise floor (thus degrade performance). Note also that not all measurements are about interference. Antenna patterns and such you just want a more accurate measurement.
  - amelius 3y ago
    You still basically need only the performance of the original devices perhaps plus a little more. This also holds for the antenna application.
myself248 3y ago
Aren't there tons of situations where you'd see >250 BLE devices? Seems to me that fixing the software to not crash should also be a very, very high priority... But yeah, chambers can be real cheap. My standard is a trash-picked microwave oven, with the magnetron and trafo removed to make it a lot lighter weight. The door is perfect, the isolation is already great at 2.4GHz, there's even a window so you can see status lights.

amelius 3y ago

If you think about it, it is a kind of ridiculous idea that you would need super-sensitive equipment to determine if some cheap device would interfere with the workings of some other relatively cheap device.

mNovak 3y ago
Do you need sensitive equipment to see if something is totally destroying performance? No. But arguably by definition, you need the ability to reliably measure at or below the noise floor in order to determine if some emitter is putting out interference that will raise the noise floor (thus degrade performance). Note also that not all measurements are about interference. Antenna patterns and such you just want a more accurate measurement.
- amelius 3y ago
  You still basically need only the performance of the original devices perhaps plus a little more. This also holds for the antenna application.

myself248 3y ago

Aren't there tons of situations where you'd see >250 BLE devices? Seems to me that fixing the software to not crash should also be a very, very high priority... But yeah, chambers can be real cheap. My standard is a trash-picked microwave oven, with the magnetron and trafo removed to make it a lot lighter weight. The door is perfect, the isolation is already great at 2.4GHz, there's even a window so you can see status lights.