Looking for some advice on how to handle connectivity issues in damp/wet weather.
We've found that our NRF51 device works well indoors, but when placed outdoors overnight, the ability to connect to the device can fall to near zero percent chance in the morning.
Notably, if we take the unit back inside to warm up/dry out, it goes back to connecting flawlessly within 10-15 minutes.
We're encased in a plastic water resistant housing, but certainly the damp/moist air can get at our system. We're connecting to the device using a mobile phone, from within 3 feet away. Most of our embedded connectivity parameters are "default" from Nordic examples, including transmitting at 0 dBm. We are using a PCB-based antenna.
The design we're using is actually the same as another "non-Nordic" solution where we've just replaced the processor core with the NRF51. This problem isn't seen on the "other" (non-Nordic based) PCB.
I had considered possible problems with the crystals, so I changed the code from using an external crystal to internal RC. This improved things quite a bit, but still hasn't proven fully capable. Some devices are connecting 1 in 3 attempts, others are not. iPhones went from zero percent chance of working to non-zero, but still far from perfect.
We've attempted to put the unit in the freezer, and didn't see the same problems.
Wondering what I should be looking at more closely, or attempting to try?
It's pretty hard to get a unit back in the lab to look at more closely when 10-15 minutes after being indoors it goes back to working state.
Any advice/suggestions would be greatly appreciated.
Cheers!
