Rogério Oliveira's Projects
Enable your Arduino to convert hexadecimal to decimal and more...
RFID Reader SDK for arduino
Awesome React Native components, news, tools, and learning material!
Base Rails Application
Deep leraning cryptocurrency prediction with blockchain-based dataset
Source Files for the Tuts+ Course: Build a Social App With React Native
Build a Social App With React Native
This is a simple casino build with solidity, truffle and react
Prepare for IT Certifications Exams ( Survey and Design Certification Exam)
Proof of Existence + Links + Files + Blockchain.
pragma solidity ^0.4.18; /** * ERC 20 token * https://github.com/ethereum/EIPs/issues/20 */ interface Token { /// @return total amount of tokens /// function totalSupply() public constant returns (uint256 supply); /// do not declare totalSupply() here, see https://github.com/OpenZeppelin/zeppelin-solidity/issues/434 /// @param _owner The address from which the balance will be retrieved /// @return The balance function balanceOf(address _owner) public constant returns (uint256 balance); /// @notice send `_value` token to `_to` from `msg.sender` /// @param _to The address of the recipient /// @param _value The amount of token to be transferred /// @return Whether the transfer was successful or not function transfer(address _to, uint256 _value) public returns (bool success); /// @notice send `_value` token to `_to` from `_from` on the condition it is approved by `_from` /// @param _from The address of the sender /// @param _to The address of the recipient /// @param _value The amount of token to be transferred /// @return Whether the transfer was successful or not function transferFrom(address _from, address _to, uint256 _value) public returns (bool success); /// @notice `msg.sender` approves `_addr` to spend `_value` tokens /// @param _spender The address of the account able to transfer the tokens /// @param _value The amount of wei to be approved for transfer /// @return Whether the approval was successful or not function approve(address _spender, uint256 _value) public returns (bool success); /// @param _owner The address of the account owning tokens /// @param _spender The address of the account able to transfer the tokens /// @return Amount of remaining tokens allowed to spent function allowance(address _owner, address _spender) public constant returns (uint256 remaining); event Transfer(address indexed _from, address indexed _to, uint256 _value); event Approval(address indexed _owner, address indexed _spender, uint256 _value); } /** @title Publica Pebbles (PBL contract) **/ contract Pebbles is Token { string public constant name = "Pebbles"; string public constant symbol = "PBL"; uint8 public constant decimals = 18; uint256 public constant totalSupply = 33787150 * 10**18; uint public launched = 0; // Time of locking distribution and retiring founder; 0 means not launched address public founder = 0xa99Ab2FcC5DdFd5c1Cbe6C3D760420D2dDb63d99; // Founder's address address public team = 0xe32A4bb42AcE38DcaAa7f23aD94c41dE0334A500; // Team's address address public treasury = 0xc46e5D11754129790B336d62ee90b12479af7cB5; // Treasury address mapping (address => uint256) public balances; mapping (address => mapping (address => uint256)) public allowed; uint256 public balanceTeam = 0; // Actual Team's frozen balance = balanceTeam - withdrawnTeam uint256 public withdrawnTeam = 0; uint256 public balanceTreasury = 0; // Treasury's frozen balance function Pebbles() public { balances[founder] = totalSupply; } function transfer(address _to, uint256 _value) public returns (bool success) { if (balances[msg.sender] < _value) { return false; } balances[msg.sender] -= _value; balances[_to] += _value; Transfer(msg.sender, _to, _value); return true; } function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) { if (balances[_from] < _value || allowed[_from][msg.sender] < _value) { return false; } allowed[_from][msg.sender] -= _value; balances[_from] -= _value; balances[_to] += _value; Transfer(_from, _to, _value); return true; } function balanceOf(address _owner) public constant returns (uint256 balance) { return balances[_owner]; } function approve(address _spender, uint256 _value) public returns (bool success) { allowed[msg.sender][_spender] = _value; Approval(msg.sender, _spender, _value); return true; } function allowance(address _owner, address _spender) public constant returns (uint256 remaining) { return allowed[_owner][_spender]; } /**@dev Launch and retire the founder */ function launch() public { require(msg.sender == founder); launched = block.timestamp; founder = 0x0; } /**@dev Give _value PBLs to balances[team] during 5 years (20% per year) after launch * @param _value Number of PBLs */ function reserveTeam(uint256 _value) public { require(msg.sender == founder); require(balances[founder] >= _value); balances[founder] -= _value; balanceTeam += _value; } /**@dev Give _value PBLs to balances[treasury] after 3 months after launch * @param _value Number of PBLs */ function reserveTreasury(uint256 _value) public { require(msg.sender == founder); require(balances[founder] >= _value); balances[founder] -= _value; balanceTreasury += _value; } /**@dev Unfreeze some tokens for team and treasury, if the time has come */ function withdrawDeferred() public { require(msg.sender == team); require(launched != 0); uint yearsSinceLaunch = (block.timestamp - launched) / 1 years; if (yearsSinceLaunch < 5) { uint256 teamTokensAvailable = balanceTeam / 5 * yearsSinceLaunch; balances[team] += teamTokensAvailable - withdrawnTeam; withdrawnTeam = teamTokensAvailable; } else { balances[team] += balanceTeam - withdrawnTeam; balanceTeam = 0; withdrawnTeam = 0; team = 0x0; } if (block.timestamp - launched >= 90 days) { balances[treasury] += balanceTreasury; balanceTreasury = 0; treasury = 0x0; } } function() public { // no direct purchases revert(); } }
Blog code samples
pragma solidity ^0.4.18;
Create React Native apps that run on iOS, Android, and web
An educational project, demonstrating how to build a large scalable project with Javascript.
CryptoCompare JavaScript API
Analysis and visualisation of the cryptocurrency market
This repo contains the code for the DGD Swap Contract. If you want to exchange your DGD tokens for Ether in an OTC manner, you can use this contract code to deploy your own contract through Mist. More information about deploying this contract can be found at -
A bitcoin trading bot written in node - https://gekko.wizb.it/
Programming examples from the book.
Exemplos práticos abordado nas aulas
Just Announced - "Learn Spring Security OAuth":
Projeto Open Source Java - NFe, NFce
A simple Vanilla LSTM model is demonstrated for time-series energy usage forecasting. Required formatting of data, building the LSTM model and walk-forward validation is demonstrated for multi-step forecasting.
Indicadores para MetaTrader 5
Rails 5 JSON:API demo app
Standard set of easy to use animations and declarative transitions for React Native
A Camera component for React Native. Also supports barcode scanning!
Device Information for React Native iOS and Android