pragma solidity ^0.4.22;

contract Iotether{
    address owner;
    uint limit;
    uint fee_per_second;
    constructor() public{
        owner = msg.sender;
        limit = 0;
    }

    event onGpio(uint pin, uint limit);

    function changeFee(uint price_per_second) public {
        require(owner == msg.sender, "Solo propietario");
        fee_per_second = price_per_second;
    }

    function getLimit() public view returns (uint) {
        return limit;
    }

    function SwitchOn() public payable{
        uint sec;
        sec = msg.value/fee_per_second;
        if (limit < block.timestamp){
            limit = block.timestamp+sec;
        }else{
            limit = limit + sec;
        }
        emit onGpio(1, limit);
    }

}