Bushfire Prevention Simulation

This is an Ethereum dapp that simulates a wireless sensor network architecture which aims to help prevent bushfires.

Software used

Front-end:

• Node.js web app

Back-end:

• Ganache
• Node.js
• Truffle
• Ethereum blockchain

Text editor:

• Atom

Guide to setting up and running the dapp

Directory information

• contracts - Ethereum smart contracts written in the Solidity language
• migrations - Migration scripts (run when migrating the compiled smart contracts onto the blockchain)
• src - Source code for Node.js web app GUI frontend
• test - Test cases for smart contracts written in Javascript and Solidity

Note on smart contract naming

During much of the initial development phase, some of the smart contracts had very different names. They are shown in the table below.

Current name	Old name
NodeEntries	NetworkFormation
NodeEntryLib	SensorNode
NodeRoleEntries	NetworkFormation2
NodeRoleEntryLib	SensorNode2

Tips

Note on contract size

It cannot exceed 24KB in size!

Difference between 'instance.myMethod()' and 'instance.myMethod.call()'

Truffle normally can auto-detect method calls as transactions (which modify the state and cost gas) or calls (which only reads the state and won't cost gas). To avoid gas costs, use the .call() method.

https://www.trufflesuite.com/docs/truffle/getting-started/interacting-with-your-contracts

Number format of uint256 var in JavaScript

A 'BN' instance.

https://ethereum.stackexchange.com/questions/79349/what-is-words-in-uint256

Preventing errors

'Error: ENOSPC: System limit for number of file watchers reached'

Temporary fix: sudo sysctl fs.inotify.max_user_watches=524288 && sudo sysctl -p

Don't make it permanent as it can lead to memory issues.

https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers#the-technical-details

A node.js dependency refuses to install

npm ERR! code ENOLOCAL
npm ERR! Could not install from "node_modules/truffle-blockchain-utils/node_modules/web3/bignumber.js@git+https:/github.com/frozeman/bignumber.js-nolookahead.git#57692b3ecfc98bbdd6b3a516cb2353652ea49934" as it does not contain a package.json file.

Delete the package-lock.json file and run npm install again!

Force update of smart contract

Delete the build folder before compiling.

TODO

• [DONE] Rename 'NetworkFormation2' and 'SensorNode2' to something else that makes more sense. e.g. 'NodeRoleEntries' and 'NodeRoleEntry'.
• [SEE IF I CAN DO THIS] Idea: Each actuator behaves differently to the sensor readings - e.g. 1 would trigger at 37000 while another would trigger at 5000.
• [ONGOING] Clean up the code and add comments to make it more presentable.
• [TODO] Seriously consider using IPFS to store node information and readings.
• [DONE] Make network react to different stimuli:
  • If sensor detects temp is > 37 degrees, alert controller, which in turn alerts the actuator and makes it trigger a device (sprinkler, alert fire services, etc).
  • If sensor temp is > 45 degrees, deactivate the sensor!
  • [DONE] Update test cases so that it shows that the actuator nodes got the message.
• [DONE] Add new flag to indicate if node is actuator, sensor, or controller. This can be done as an enum if possible.
  • Idea: sensor and actuator are leaf nodes (or cluster heads with no children). The remaining cluster heads are the controller nodes.
• [DONE] Implement the actual redundancy - when a node's cluster head fails, make that node connect to its backup cluster head.
• [DONE] Add test cases for newly added backup cluster heads (ensure the correct ones are being nominated)
• Refactor the code to allow for further expansion. Idea: split up NetworkFormation into several, smaller contracts.
• Make approval automatic.