ertlnagoya / web3-arduino

an Arduino (or ESP32) library to use web3 on Ethereum platform.

web3-arduino

• What is this library?

  • This is an Arduino (or ESP32) library to use web3 on Ethereum platform.

• What is Arduino?

  • Arduino is an open source computer hardware and software.
  • https://www.arduino.cc/

• What is ESP32?

  • ESP32 is a series of low cost, low power system on a chip microcontrollers with integrated Wi-Fi and dual-mode Bluetooth.
  • https://www.espressif.com/en/products/hardware/esp32/overview

• What is web3?

  • Web3 is the Ethereum compatible API which implements the Generic JSON RPC spec. Originally Javascript version is developed.
  • https://github.com/ethereum/web3.js/

• What is Ethereum?

  • Ethereum is a decentralized platform for applications that run exactly as programmed without any chance of fraud, censorship or third-party interference.
  • https://www.ethereum.org/

Environment

• Confirmed device
  • ESP-WROOM-32
• Used Ethereum client
  • localhost (hardhat)

Installation

1. download the zip file from Clone or download button on Github.
2. launch Arduino IDE.
3. Sketch -> Include Library -> Add .ZIP file -> select downloaded zip file.
4. Then you can use this from Arduino IDE.

Example

Please refer examples directory.

setup

String account = "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266";
String contract_address = "0x5FbDB2315678afecb367f032d93F642f64180aa3";

Web3 web3("localhost", "http://192.168.0.9:8545/");

call web3 methods

Serial.println(web3.Web3ClientVersion());
Serial.println(web3.Web3Sha3("0x68656c6c6f20776f726c64"));
Serial.println(web3.NetVersion());
Serial.println(web3.NetListening());
Serial.println(web3.NetPeerCount());
Serial.println(web3.EthProtocolVersion());
Serial.println(web3.EthSyncing());
Serial.println(web3.EthMining());
Serial.println(web3.EthGasPrice());
Serial.println(web3.EthBlockNumber());
Serial.println(web3.EthGetBalance(account));
Serial.println(web3.EthGetTransactionCount(account));

call to Contract

Contract contract(&web3, contract_address);
contract.SetPrivateKey(PRIVATE_KEY);
contract.SetAccount(account);

sendTransaction to Contract

String retrieve_code = contract.SetupContractData("f", "retrieve()");
Serial.println(contract.Call(retrieve_code));

String store_code = contract.SetupContractData("fu", "store(uint256)", 123);
Serial.println(contract.SendTransaction(store_code));

Serial.println(contract.Call(retrieve_code));

Dependency

• [ArduinoJson] (https://arduinojson.org/)
• [HTTPClient] (https://www.arduino.cc/reference/en/libraries/httpclient/)
• ESP32-Arduino