How to make an Ethereum Transaction, & check your balance?Once you have managed to set up an Ethereum Miner using either your GPU or your CPU – it’s time to start checking your balance and start trading.We’re going to show you how you can check your balance in Command Prompt, how to convert between all the different values of Ether, such as the base unit Wei, and how to make your first transaction!Once you have set up your miner via running the Geth program and Ethminer program (see our guide here on how to get started), you need to open up a third Command Prompt Window.Step 1: This can be done by right clicking on the command prompt in the taskbar at the bottom of your screen – and then clicking on the command prompt that appears at the top of the menu.A third command prompt should now be open.Step 2: You now need to tell this Command Prompt where to look to get up and running.Usually the command Prompt window opens looking at your user profile.If this is the case you need to tell Command Prompt to go to wherever you installed geth.

In our guide we installed it straight on the C Drive – so we need to tell command prompt to get back to the C Drive – which we do by typing in “cd C:\” and pressing enter.Step 3: You then need to tell Command Prompt what to do.In this case you need to tell it to attach to Geth.So all you type in is “geth attach” – which should look like this “C:/>geth attach” – and then press enter.You now have a console up and running – talking to geth – so you can start asking it questions – or telling it to do things.Remember for "geth attach" to work you need to have another Command Prompt Window running with "geth --rpc".If you want to find out your address you type in “eth.coinbase”.This should look like this “C:/>eth.coinbase”.Press enter and you should see your address appear – which is a long string (set of characters and numbers – to find out how your address is generated and about private and public keys  see our guides here).If you want to check your balance you can simply type in this command here  “eth.getBalance(eth.coinbase)” and hit enter.

Make sure you capitalise the B in "balance" and also bear in mind that this gives your balance in Wei – one of the smaller denominations of Ether – just like satoshi in Bitcoin and cents in dollars.If you want to check your balance in Ether you need to type in the following code “web3.fromWei(eth.getBalance(eth.coinbase),"ether")” and press enter – and likewise in other denominations of Ether just change the end of the sentence to include the denomination you want to convert to.So if you want to convert to finney or Shannon follow these two commands here “web3.fromWei(eth.getBalance(eth.coinbase),"finney")” or “web3.fromWei(eth.getBalance(eth.coinbase),"shannon")”.Remember to capitalise the B in the getBalance bit and if you want to learn more about the existing options, checkout out our guide on different denominations of Ether.If you want to send a transaction from your address type in the following command: eth.sendTransaction({from: eth.coinbase, to: "0x154230ed91d1e711e56b9c0f88b5ba5fd2b0503f", value: web3.toWei(1, "ether"),gas:22000,gasPrice:web3.toWei(45,"Shannon"),data: web3.toHex('ZeroCool')}) The simple version for this, without any optional fields is: eth.sendTransaction({from: eth.coinbase, to: "0x154230ed91d1e711e56b9c0f88b5ba5fd2b0503f", value: web3.toWei(1, "ether")}) Lets break this down a bit so you can understand what each bit means: eth.sendTransaction – means you are telling geth to send a transaction.

({from: eth.coinbase, - you are telling geth to take the ether from your address – coinbase just means your own address.to: "0x154230ed91d1e711e56b9c0f88b5ba5fd2b0503f", - means the address you are sending the Ether to.value: web3.toWei(1, "ether"), - is the value you are sending – you can change the value of 1 to other denominations of ether and long as you change the second part of the brackets to the denomination term you are sending in.bitcoin riminigas:22000,gasPrice:web3.toWei(45,"Shannon"), - OPTIONAL - this shows you how much gas you want to pay for the transaction.bitcoin mining with nvidia geforceGas is the pricing mechanism for a transaction – when in fact it is ultimately Ether and controlled by how many people want to use the network at that time.bitcoin asic miner list

For a more in depth look at what gas is check out our article on gas!If you don't include gas and gasPrice it will use the current network default.data: web3.toHex('ZeroCool')}) - OPTIONAL - is a tag to the transaction – just like you put on any bank transfer.You can put as many characters as you want, but the higher the number of the more gas it will cost to process the transaction.jak zakupić bitcoinThe have the cheapers transfer fee just don't include this option.bitcoin miner für androidNow you have learnt how to do a transaction you can start transferring your ether to an exchange like Kraken or Poloniex to begin trading.ethereum madridThe easier way to do this would be by using the Ethereum Wallet Dapp but do keep in mind that this is still in beta.Related guides What is Ether in Ethereum?

How are Ether currency units issued in Ethereum?Why is Ethereum different to Bitcoin?How to Buy Ethereum?What are Mining Rewards in Ethereum?What is the GHOST protocol for Ethereum?Popular guides CryptoCompare Portfolio FAQ Where to spend your Bitcoins How to use MyEtherWallet How to mine Zcash - Who we are!How to Add Sold Coins on the CryptoCompare PortfolioBroadly speaking there are three types transactions supported on Ethereum: To undertake any of these transactions, it is necessary to have Ether (the fuel of the Ethereum blockchain) residing in the Ethereum account which the transactions are taking place from.This is to pay for the costs, which is the transaction execution cost for the Ethereum client that performs the transaction on your behalf, comitting the result to the Ethereum blockchain.Instructions for obtaining Ether are described below in .Additionally, it is possible to query the state of a smart contract, this is described in .

Obtaining Ether To obtain Ether you have two options: Mine it yourself Buy Ether from another party Mining it yourself in a private environment, or the public tet environment (testnet) is very straight forwards.However, in the main live environment (mainnet) it requires significant dedicated GPU time which is not likely to be feasible unless you already have a gaming PC with multiple dedicated GPUs.If you wish to use a private environment, there is some guidance on the Homestead documentation.To purchase Ether you will need to go via an exchange.As different regions have different exchanges, you will need to research the best location for this yourself.The Homestead documentation contains a number of exchanges which is a good place to start.Alternatively, if you need some Ether on testnet to get started, please post a message with your wallet address to the web3j Gitter channel and I’ll send you some.Mining on testnet/private blockchains In the Ethereum test environment (testnet), the mining difficulty is set lower then the main environment (mainnet).

This means that you can mine new Ether with a regular CPU, such as your laptop.What you’ll need to do is run an Ethereum client such as Geth or Parity to start building up reserves.Further instructions are available on the respective sites.Geth /ethereum/go-ethereum/wiki/Mining Parity /paritytech/parity/wiki/Mining Once you have mined some Ether, you can start transacting with the blockchain.Gas When a transaction takes place in Ethereum, a transaction cost must be paid to the client that executes the transaction on your behalf, committing the output of this transaction to the Ethereum blockchain.This cost is measure in gas, where gas is the number of instructions used to execute a transaction in the Ethereum Virtual Machine.Please refer to the Homestead documentation for further information.What this means for you when working with Ethereum clients is that there are two parameters which are used to dictate how much Ether you wish to spend in order for a tranaction to complete: Gas price -15 Gas limit This is the total amount of gas you are happy to spend on the transaction execution.

There is an upper limit of how large a single transaction can be in an Ethereum block which restricts this value typically to less then 1,500,000.The current gas limit is visible at https://ethstats.net/.These parameters taken together dictate the maximum amount of Ether you are willing to spend on transaction costs.you can spend no more then gas price * gas limit.The gas price can also affect how quickly a transaction takes place depending on what other transactions are available with a more profitable gas price for miners.You may need to adjust these parameters to ensure that transactions take place in a timely manner.Transaction mechanisms When you have a valid account created with some Ether, there are two mechanisms you can use to transact with Ethereum.Both mechanisms are supported via web3j.Transaction signing via an Ethereum client In order to transact via an Ethereum client, you first need to ensure that the client you’re transacting with knows about your wallet address.

You are best off running your own Ethereum client such as Geth/Parity in order to do this.Once you have a client running, you can create a wallet via: The Geth Wiki contains a good run down of the different mechanisms Geth supports such as importing private key files, and creating a new account via it’s console Alternatively you can use a JSON-RPC admin command for your client, such as personal_newAccount for Parity or Geth With your wallet file created, you can unlock your account via web3j by first of all creating an instance of web3j that supports Parity/Geth admin commands: = .(Then you can unlock the account, and providing this was successful, send a transaction: = .(,{ } Transactions for sending in this manner should be created via EthSendTransaction, with the Transaction type: = .( value is obtained as per .Please refer to the integration test DeployContractIT and its superclass Scenario for further details of this transaction workflow.

Further details of working with the different admin commands supported by web3j are available in the section Management APIs.Offline transaction signing If you’d prefer not to manage your own Ethereum client, or do not want to provide wallet details such as your password to an Ethereum client, then offline transaction signing is the way to go.Offline transaction signing allows you to sign a transaction using your Ethereum Ethereum wallet within web3j, allowing you to have complete control over your private credentials.A transaction created offline can then be sent to any Ethereum client on the network, which will propagate the transaction out to other nodes, provided it is a valid transaction.Creating and working with wallet files In order to sign transactions offline, you need to have either your Ethereum wallet file or the public and private keys associated with an Ethereum wallet/account.web3j is able to both generate a new secure Ethereum wallet file for you, or work with an existing wallet file.

To create a new wallet file: = .(,( To load the credentials from a wallet file: = .(,These credentials are then used to sign transactions.Please refer to the Web3 Secret Storage Definition for the full wallet file specification.Signing transactions Transactions to be used in an offline signing capacity, should use the RawTransaction type for this purpose.The RawTransaction is similar to the previously mentioned Transaction type, however it does not require a from address, as this can be inferred from the signature.In order to create and sign a raw transaction, the sequence of events is as follows: Identify the next available for the sender account Create the RawTransaction object Encode the RawTransaction object Sign the RawTransaction object Send the RawTransaction object to a node for processing The nonce is an increasing numeric value which is used to uniquely identify transactions.A nonce can only be used once and until a transaction is mined, it is possible to send multiple versions of a transaction with the same nonce, however, once mined, any subsequent submissions will be rejected.

Once you have obtained the next available , the value can then be used to create your transaction object: = .(,< < < < The transaction can then be signed and encoded: = .(,Where the credentials are those loaded as per .The transaction is then sent using eth_sendRawTransaction: = .(Please refer to the integration test CreateRawTransactionIT for a full example of creating and sending a raw transaction.The transaction nonce The nonce is an increasing numeric value which is used to uniquely identify transactions.You can obtain the next available nonce via the eth_getTransactionCount method: = .(,The nonce can then be used to create your transaction object: = .(,< < < < Transaction types The different types of transaction in web3j work with both Transaction and RawTransaction objects.The key difference is that Transaction objects must always have a from address, so that the Ethereum client which processes the eth_sendTransaction request know which wallet to use in order to sign and send the transaction on the message senders behalf.

As mentioned , this is not necessary for raw transactions which are signed offline.The subsequent sections outline the key transaction attributes required for the different transaction types.The following attributes remain constant for all: Gas price Gas limit Nonce From Transaction and RawTransaction objects are used interchangeably in all of the subsequent examples.Transfer of Ether from one party to another The sending of Ether between two parties requires a minimal number of details of the transaction object: to the destination wallet address value the amount of Ether you wish to send to the destination address = .(,< < < Creation of a smart contract To deploy a new smart contract, the following attributes will need to be provided value the amount of Ether you wish to deposit in the smart contract (assumes zero if not provided) data the hex formatted, compiled smart contract creation code = .(<<<<

= ( <> = .If the smart contract contains a constructor, the associated constructor field values must be encoded and appended to the compiled smart contract code: =.(.(+ Transacting with a smart contract To transact with an existing smart contract, the following attributes will need to be provided: to the smart contract address value the amount of Ether you wish to deposit in the smart contract (assumes zero if not provided) data the encoded function selector and parameter arguments web3j takes care of the function encoding for you, further details are available in the Ethereum Contract ABI section of the Ethereum Wiki.< < , < ...... =.(It is not possible to return values from transactional functional calls, regardless of the return type of the message signature.However, it is possible to capture values returned by functions using filters.Please refer to the Filters and Events section for details.Querying the state of a smart contract This functionality is facilitated by the eth_call JSON-RPC call.