In SX Microcontrollers, SX/B Compiler and SX-Key Tool, markistuff wrote:

Hi all,  
funny this topic was brought up.  thats a cool idea for making an sx controlled timer.  some commerical timers have wireless rain detectors for them. but what would be cooler is have something that senses how wet the ground is and weather it needs watered or not.

 

 currently im working for a company installing sprinklers for resdential and large scale commerical grounds. (please excuse my spelling)  The thing that costs alot of money on the large jobs is the copper.  its over 200 bucks for 500 feet of 7 strand direct burrial copper wire.  and figure your running 5 or 6 valve boxes that each need thier own wires,  thats alot of money.  we came up with the idea a few days ago on one job site to use the a couple of sx's.  put one in were the timer is, have it connected to all the outputs from the timer.  use it as an encoder,  then run 2 or 3 wires to all the valve boxes. just one set of wire that goes to everything. then have another sx at each box that acts as a decoder.   this way you can cut the amount of wire needed drimaticly.  now most common valves are AC power  so 2 of the wires you run to the boxes one for common and the other is the ac power.  use a dioide brindge and voltage regulator to get power to run the sx.  and then have the sx run a small relay that will basicly connect whatever valve is being triggered to the power.  and the third wire is used for the the digital signal.  now becuase its going very long distences from one sx to another running serial data at high speeds most likely will not work but maby if eash pulse is like for 1 second or somehting like that, and also on the encoder sx have it go through a transistor to boost the power or somehting like that.  now thats using 3 wires.  i know you can overlay an AC signal on a DC powerline and isolate it.  but could you do the opposite.  just run the serial data as a DC signal over the AC power line to each box?  if so then the wires needed will drop to 2.  unless you can make the whole thing wireless and have a really good battery.   tell me if any of this makes sence or not.  my boss told me to make a prototype to see how it would work.  any ideas or sugestions?

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