FundMe Smart Contract Documentation

Overview

The FundMe smart contract is designed to allow users to contribute Ether (ETH) to a crowdfunding campaign. The contract enforces a minimum funding amount in USD and uses Chainlink's price feed to determine the ETH to USD conversion rate.

Smart Contract Details

State Variables

• minimumUSD: The minimum amount in USD that must be contributed to the campaign. Default is set to 50 ETH.
• funders: An array containing the addresses of users who have contributed to the campaign.
• addressToAmountFunded: A mapping that tracks the amount each funder has contributed.

Functions

• fund(): Allows users to contribute funds to the campaign. Requires the sent amount to meet the minimum USD requirement.
• getPrice(): Retrieves the latest ETH to USD conversion rate using Chainlink's AggregatorV3Interface.
• getVersion(): Retrieves the version of the Chainlink AggregatorV3Interface being used.
• getConversionRate(uint256 ethAmount): Calculates the equivalent USD amount for the provided ETH amount.

Usage

1. Setting Minimum Contribution Amount:

   • The minimumUSD variable can be adjusted to set the minimum contribution amount in USD.

2. Contributing Funds:

   • Users can contribute funds by calling the fund() function, ensuring they send the required ETH amount to meet the minimum USD requirement.

3. Viewing Conversion Rate:

   • The getPrice() function provides the latest ETH to USD conversion rate.

4. Viewing Contract Version:

   • The getVersion() function retrieves the version of the Chainlink AggregatorV3Interface.

5. Viewing Conversion Rate for a Specific ETH Amount:

   • The getConversionRate(uint256 ethAmount) function calculates the equivalent USD amount for a given ETH amount.

Example

// Example: Contributing 2 ETH to the FundMe contract
contract.fund({value: 2 * 1e18});

// Example: Retrieving the latest ETH to USD conversion rate
uint256 ethToUsdRate = contract.getPrice();

// Example: Retrieving the version of the Chainlink AggregatorV3Interface
uint256 version = contract.getVersion();

// Example: Calculating USD equivalent for 2 ETH
uint256 usdEquivalent = contract.getConversionRate(2 * 1e18);

Notes

• Ensure that the Chainlink AggregatorV3Interface contract address (0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419) remains up-to-date.
• Additional functions, such as withdrawal, can be implemented based on project requirements.

Feel free to extend and customize the contract as needed for your specific use case.