WeiGold: Fair Value Commodities Vending Machine

Overview

WeiGold ensures fair, transparent vending for physical gold based on Chainlink's commodities pricefeed aggregators.

Solo project by Marcus Wentz.

Chainlink Hackathon Fall 2021.

WeiGold Youtube presentation with demo:

https://www.youtube.com/watch?v=nxwqg_YGh0c

WeiGold's structure:

Hardware used:

-Raspberry Pi 4 [Quantity: 1]
-S90 Servo Motors [Quantity: 3]
-A cardboard box [Quantity: 1]

Wiring diagram:

Hardware Javascript Programming Instructions:

1a.Install web3.js and pi-blaster.js with Node.js on wired Raspberry Pi 4
1b.web3.js: npm install web3
1c.pi-blaster.js:  Build and install directly from source: https://github.com/sarfata/pi-blaster 
2.Have the "HardwareServoControl.js" script running on the wired Raspberry Pi 4
3.Connect to site with Metamask on Sepolia [make sure you have some free Sepolia Ethereum to modify contract states]
(you can create your own custom contract by redeploying on Remix and changing address and ABI for FrontEnd and Servo scripts)
4.Interact with the contract and watch the servos move based on contract State!

Bridge ETH from Sepolia to Optimism Sepolia:

https://superbridge.app/op-sepolia

WeiGold.sol on Optimism Sepolia (verified on Etherscan):

https://sepolia-optimism.etherscan.io/address/0x8aa8d378effa946a8d8c6214116027cf40714e93

Website live on GitHub pages:

https://marcuswentz.github.io/WeiGold/index.html?

Run website locally with

npx http-server

Foundry Forge Commands

Install Solmate Library

forge install rari-capital/solmate --no-commit

Install Chainlink Library

forge install smartcontractkit/chainlink-brownie-contracts --no-commit

Tests while forking a network

forge test --fork-url $optimismSepoliaHTTPS

Tests while forking a network with test coverage report

forge coverage --fork-url $optimismSepoliaHTTPS --report lcov && genhtml lcov.info -o report --branch-coverage

Forge deploy and verify contract

forge create src/WeiGold.sol:WeiGold \
--private-key $devTestnetPrivateKey \
--rpc-url $optimismSepoliaHTTPS \
--etherscan-api-key $optimismEtherscanApiKey \
--verify