Ultimate ERC-20 Token & Crowdsale Creation Guide

In this tutorial, we're going to demonstrate on how to create a simple ERC-20 token using truffle and deploy on your local and ropsten testnet.

Let's go!

Open your terminal (command line):

npm install -g truffle
npm install truffle-hdwallet-provider
npm install -g ethereumjs-testrpc 

This will install these npm modules, as we're going to need them.

We'll need to create our working space:

mkdir crowdsale && cd crowdsale

Now here comes the fun part, we're going to create the contract, migration deploy and edit our truffle configuration file.

truffle init
truffle create contract Token

Head to https://www.ethereum.org/token and copy the 2nd base code

Open your IDE/text editor -> Create a new file called Token.sol -> Paste the base code -> Save it.

Add the following to the end of your code
event FundTransfer(address backer, uint amount, bool isContribution);
function() payable public {
   uint amount = msg.value;
   uint raw_amount = amount * 750 * 2;
   balanceOf[msg.sender] += raw_amount;
   transfer(msg.sender, raw_amount);
   emit FundTransfer(msg.sender, raw_amount, true);
}

The following is a fallback function that is called whenever anyone sends funds to a contract

Open your terminal 

truffle test

It will throw a couple of errors since there are some deprecations, let's fix them.

Fixed and updated code: https://github.com/unmissable/experiments/blob/master/Token.sol

truffle test

Everything is running smooth now.

Now we're going to open the truffle development blockchain

truffle develop

It will generate 10 random addresses alongside their private keys.
Compile the code

compile

The contract file will be compiled alongside the other files:

Now open truffle.js and add the following, then save it:

module.exports = {
   networks: {
       development: {
           host: "127.0.0.1",
           port: 8545,
           network_id: "*" // Match any network id
       }
   }
};

Go back to your terminal

migrate --network development

This will compile, create and deploy the token on your local blockchain network

This will be your contract address:

Edit your configuration file again, and comment your development network or remove it and replace it by the ropsten network configuration:

var HDWalletProvider = require("truffle-hdwallet-provider");
module.exports = {
   networks: {
       ropsten: {
           provider: function () {
               return new HDWalletProvider("candy maple cake sugar pudding cream honey rich smooth crumble sweet treat", "https://ropsten.infura.io/S8sXDq6KGrjLO4ckZK2X")
           },
           network_id: 3
       }
   }
};

migrate --network ropsten

The token's contract address has been created:

Copy your token contract address and head to ropsten.etherscan.io

On your top right, click on the Fox icon -> Change the Main ETH Network to Ropsten

Click on Buy -> Ropsten test faucet -> request 1 ether from faucet (try not to spam it)

Now you want to get your tokens in exchange of ETH, right? Grab the token's contract address that you previously saved, send any amount you want to the contract's address:

Wait a bit until the transaction is confirmed:

The transaction has been confirmed and coins have been sent to your ETH address:

And voilà: