const web3 = require('web3');
const EthereumTx = require('ethereumjs-tx');
const address = 'publicAddress';
const privateKey = Buffer.from('privateKey', 'hex');

const txParams = {
  nonce: web3.toHex(web3.eth.getTransactionCount(address)),
  to: destAddress,
  gasPrice: web3.toHex(21000000000),
  gasLimit: web3.toHex(21000),
  value: web3.toHex(web3.toWei(1, 'ether')),
  data: '',
  // EIP 155 chainId - mainnet: 1, ropsten: 3
  // chainId: 3
};

const tx = new EthereumTx(txParams);
tx.sign(privateKey);
const serializedTx = tx.serialize();
// const serializedTx = `0x${tx.serialize().toString('hex')}`;
/*web3.eth.sendRawTransaction(serializedTx, (error, data) => {
  if (!error) {
    return console.log(data);
  }
  return console.log(error);
});*/