74c1f5e5   
   XPost: sci.electronics.design, sci.electronics.misc   
   From: adrian@qq.vv.net   
      
   On 7/3/2013 8:05 AM, RichD wrote:   
   > Wireless is everywhere now, miniaturized to an astounding degree.   
   >   
   > Recently, I saw a report on a button size gardening   
   > gadget - stick it in the soil, it reports on moisture.   
   > Bluetooth earphones, etc.   
   >   
   > Who's designing these things?  In my experience, RF   
   > designers are a rare breed, and with the digital market   
   > vastly larger, they're even rarer.   
   >   
   > I'll guess, the IC have been perfected to the no-brainer   
   > level.   But still, you need need amps, filters, antenna, plus   
   > issues of noise and layout, yes/no?  That stuff isn't obsoleted.   
   >   
   > I don't work in this area, but I'm curious, so can anyone   
   > elaborate on what's going on, from a system viewpoint?   
   > What are the chip functions, options, price, trade-offs?   
   > In which situations would you reject them, to roll your own?   
   >   
   > Is it simple on/off keying, or more sophisticated?  Currently,   
   > in communications theory, sensor networks are a hot topic,   
   > where thousands of sensors are competing for bandwidth,   
   > but for mundane consumer apps, I doubt those issues arise.   
   >   
   > I'm looking to pick the brains of any gurus here -   
   >   
   >   
   > --   
   > Rich   
   >   
   >   
   >   
   You are right, but seems like someone has solved the RF problems once   
   for each of the useful bands, then its a piece of cake to interface with   
   sensors and one end and display/alarm at the other.   
      
   For an example, the tyre pressure monitor systems at 433 MHz.  10 gram   
   package, including battery, you screw on a tyre valve.  Monitors tyre   
   pressure and temperature for about 1-2 years of operation.  Reports real   
   time, every minute or so, to in-car readout.   
      
   --   
   Regards,   
      
   Adrian Jansen           adrianjansen at internode dot on dot net   
   Note reply address is invalid, convert address above to machine form.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)