How can I use Ethereum smart contracts with another crypto currency?

Question

I am learning/playing around with some concepts of the blockchain, smart contracts and Ethereum. I have created my own "toy" cryptocurency ("myCoin") by forking a coin using the CryptoNote algo.

I want to use the Ethereum platform, to write smart contracts which are "denoted" using "myCoin" currency (i.e. tokens), instead of ether.

So for example a contract might state (pseudocode):

Definition of Event A
Definition of Event B

When Event A is raised by a user
Pay user X units of myCoin

When Event B is raised by a user
Request user Y units of myCoin from user

Can someone outline the steps needed to write such smart contracts that are decoupled from ETH and instead rely on my alt coin?

Answer 1

You can provide your token smart contract-extensibility by 'wrapping your token' by something that can interact with the contracts, i.e., ERC-20 tokens.

Here is a detailed article on how to go about it. The sample Weth interface provided:

contract IWETH is ERC20 {
  event Deposit(address indexed sender, uint256 amount);
  event Withdrawal(address indexed recipient, uint256 amount);

  function deposit() public payable;

  function withdraw(uint256 amount) public;

  function withdraw(uint256 amount, address user) public;
} 

The Weth contract implementation:

contract WETH is IWETH {
  string public name = "Wrapped Ether";
  string public symbol = "WETH";
  uint8  public decimals = 18;

  function deposit() public payable {
    _mint(msg.sender, msg.value);
    emit Deposit(msg.sender, msg.value);
  }

  function withdraw(uint amount) public {
    require(balanceOf(msg.sender) >= amount);
    address payable recipient = msg.sender;
    _burn(msg.sender, amount);
    recipient.transfer(amount);
    emit Withdrawal(recipient, amount);
  }

  function withdraw(uint amount, address payable recipient) public {
    require(balanceOf(msg.sender) >= amount);
    recipient.transfer(amount);
    _burn(msg.sender, amount);
    emit Withdrawal(recipient, amount);
  }
}