Soil Sensor Patent Abstract/Figures Plan
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-Things to cover:
  -Enumeration process
  -Internal soil sensor design
-Abstract:
  -Plant science sensors comprising a microcontroller, ...blah blah blah
  -Communicates data to the control computer...
  -Discovers sensors by traversing the binary tree formed by the address bits...
-Figures:
  -Soil sensor internal block diagram
  -Enumeration process flow chart
  -Address bits/enumeration as it proceeds example
  
  
  
Abstract
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The soil sensor consists of a microcontroller, RS-485 communication interface, and a number of sensors. Sensors are connected to the microcontroller through the I2C bus, general-pupose digital input/outputs, and analog ADCs. Each soil sensor is connected to the control computer via the RS-485 bus. During normal operation, the control computer requests data from every soil sensor it knows about using that sensor's 72-bit serial number (address). During enumeration, the control computer discovers sensors connected to the bus by recursively querying the value of their address bits. This process is analogous to a depth-first traversal of a binary tree where each bit position is a level, each bit specifies the existence of a child node, and each leaf node is a complete address. To enable this, the RS-485 bus is placed in a wired-AND state, allowing conflicts in the value of an address bit to be detected. (The enumeration procedure and wired-AND behavior is the same process used by Maxim Semiconductor's 1-Wire interface protocol.)