About • Schematic • Protocol • Docs • License
The agriculture node (ag-node) is an automatic multi-weigh-station for measuring the live-weight of sheep in remote locations. The station can be situated against a trough for which sheep weights will be recorded as they access feed or water. An in-built LoRaWAN radio sends data (containing live-weight information) back to a local gateway and onto the end user. Additional interfaces are provided, including; SDI-12, I2C and OneWire to allow for various sensors to be connected to the device (such as trough level sensors, temperature monitors etc.).
The devices schematic can be found at: schematic.pdf
Basic components are summarised in the below image. Where A is the analog-to-digital converter, B is the LoRaWAN communication infrastructure and C is the peripheral sensor connectors (I2C, OneWire and SDI-12).
As the device operates autonomously (sheep are weighed in an unsupervised manner) an algorithm to capture the maximum stable weight (and an error representation) is provided.
The protocol is explained below and a visual representation is provided.
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A weight is captured (triggered by a sheep stepping on a scale) consisting of a time-series of weights while the sheep is on the platform
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This time-series data is sliced into groups of 5 values
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The slope between the first and last value is calculated (where values < 0.1) are discarded as they represent unstable weights
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The Root Mean Square Error (RMSE) of the fitted line is calculated
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The average of the 5 points are taken
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An evaluation of the new weight is made against previous slices (see figure below under the Method
Evaluatefor an equation that represents this)
Firmware documentation can be found here
An illustration of the devices operations can be found below:
Ag-node is MIT licensed, as found in the LICENSE file.