[TriEmbed] wireless communications and battery life

[Brian]

On 1/7/20 10:43 PM, Glen Smith via TriEmbed wrote:
> I'll add my welcome to Brian's, and add a +1 to most everything he said.
> 
> The only additional insight I hope to add would be that you may very 
> well be able to add a small solar cell to the top of your mailbox 

Great idea!  And very likely the complete answer to the power question, 
since the device will only be awake a tiny fraction of the day, as you 
pointed out.

> 
> You biggest problem may be transmitting through the Faraday cage of the 
> mailbox.
> 

Faraday cages aren't very effective when they aren't grounded.  If the 
mailbox doesn't have continuity to Earth (on a dried-out wooden post, 
maybe), it won't attenuate the signal as badly (RF power will still be 
lost by induced eddy currents in the metal, but the metal won't be as 
reflective as it would be if grounded).

That said, all you really have to do is get the antenna outside the box. 
  It shouldn't be too hard to find an Arduino-friendly RF module with a 
connector (SMA or UFL) instead of an onboard antenna; then a short cable 
and "rubber duck" antenna mounted outside the box is all you need.

-B