Useless Token (USEL)

ERC20 Test token on Ethereum blockchain leverages chainlink (LINK) price oracle and the new chainlink VRF to get random verified numbers.

This token rebalances every hour and affect tokens that are locked on the contract. When rebalance mechanism activates:

• Requests a random number to be generated by the chainlink VRF
• When the random number arrives get the current price of BTC/ETH pair using chainlink price oracle
• If new price is greater than the price at the previous rebalance: Mint random % of tokens for each account that have locked tokens.
• If new price is less than the price at the previous rebalance: Burn random % of tokens on each account that have locked tokens.

Kovan testnet contract => 0x44Be6b05F8011Dbb9CDe17acE93133939A82a9Fa

Usage

1. Copy the UselessToken.sol to Remix on a new Project.
2. Change the compiler version to the correct one (0.6.xx)
3. Install Metamask if you dont have it.
4. Create/Use an account on the Metamask and switch to Kovan testnet (some chainlink addresses are hardcoded so this only works on this testnet)
5. Get some ETH from the Kovan ETH faucet
6. Get some LINK from the Kovan LINK faucet
7. Add Custom Token to Metamask: 0xa36085F69e2889c224210F603D836748e7dC0088 (This is the LINK contract on Kovan testnet)
8. Go to Remix and deploy the UselessExecutor using Inject Web3 so it will connect with Metamask
9. Now we have a deployed contract, and will appear on a Deployed Contracts tab on Remix. 9.1 This is a ERC20 contract so it has the standard functionality of a ERC20 Token with some added functions 9.2 When you deployed the contract it minted some coins for you
10. Send some of you LINK tokens to the contract using Metamask 10.1 To get random numbers we need to feed LINK to the contract so it has a way to interact with chainlink VRF
11. Lock some tokens on the contract using the lockTokens function
12. See you locked tokens using getLockedBalanceOf and see you normal balance with balanceOf

For this to work the rebalance function needs to be called by some service each hour, on a mainnet environment probably a service like Ethereum Alarm Clock

For test purposes, we call this manually.

rebalanceTrigger function is the one used to trigger the rebalance, we need to provide a seed to generate some entropy. This function can take some time as the chainlink service needs to compute and return the random number!

When a rebalance is concluded, all accounts that have locked tokens have some minted or burned tokens depending on the price change of the BTC/ETH pair. The quantity of tokens minted/burned is defined by the random number that is provided by the Chainlink VRF with the following formula: (quantityLockedTokens * random%) / 100

To widthdaw locked tokens just use the withdrawLockedTokens function.