How to create a token smart contract that sends tokens after recieving payment in ether?

Question

Hey everyone I am launching an ICO. I need to create a smart contract that holds a certain amount of tokens that I created. Then when ether is sent to the smart contract address for my token. It will send back my created tokens ether equivalent value to the sending address? I also need to set the value of the tokens to .5 usd or whatever the equivalent is in ether? The contract then should send the ether to my private address. Can anyone help me or point me to some info. Thanks!

Answer 1

I guess this is what you are looking for

uint256 public totalSupply;// total no of tokens in supply
uint remaining;
uint price;
mapping (address => uint) investors //it maps no of tokens given to each address

function token(uint _totalSupply) //constructor
{
    totalSupply = _totalSupply;//set initial no of tokens in supply
    remaining = 0;
}

function ()  payable// called when ether is send
{
    assert(remaining < totalSupply);
    uint noOfTokens = div(msg.value,price); // calculate no of tokens to be issued depending on the price and ether send
    assert(noOfTokens < sub(totalSupply,remaining)); //no of tokens available should be greater than the one to be issued
    add(investors[msg.sender],noOfTokens);
    remaining = add(remaining,noOfTokens);
    transfer(msg.sender, noOfTokens);

}

function setPrice(uint _price)
{ //  price need to be set maually as it cannot be done via ethereum network
    price = _price;
}

I have included open-zepplin safe math for sub and div. While creating an ICO, remember to include all the secrurity checks, give the description about the token so that you can monitor the token easily using block explorer. You need to dynamically set price as .5 USD price is an approximate one and ethereum does not support decimal values.

Answer 2

I do not want to frustrate you, but it's harder than you expect. The first thing you should learn about Virtual Machine(EVM)

Secend thing read this post Intro to Programming Smart Contracts on Ethereum

The last thing read this article from the spiritual father of ICO he talking about How To Create Token and Initial Coin