Examples for implementing applications with chain interactions for the EV3

• Print EV3 key presses to the console: examples/key-press/waitforkeys.go
• Run a motor on pressing a button: examples/touchandgo/touch-and-go.go
• Control device state and collect metrics via smart contract: examples/devicecontrol/controlled-drill.go

Compiling Go for ARM

Compile for EV3 or BrickPi3

GOOS=linux GOARCH=arm GOARM=5 go build

Copy the compiled binaries to the device, i.e., you don't have to compile on the device.

Execute a program

./{binaryName}

Alternatively, if you are using the EV3, you may start the program from the File Browser.

Ethereum smart contract interaction

Compile go-ethereum devtools

go get -u github.com/ethereum/go-ethereum
cd $GOPATH/src/github.com/ethereum/go-ethereum/
make
make devtools

Compile contracts

solc --abi --bin --overwrite -o bin solidity/*

Generate Go contract file

abigen --bin=bin/{ContractName}.bin --abi=bin/{ContractName}.abi --pkg=contract --type={ContractName} --out=chain/contract/{contractFile}.go

All in one

abigen --sol=solidity/{contractFile}.sol --pkg=contract --type={ContractName} --out=chain/contract/{contractFile}.go

Resources:

• https://github.com/ev3go/ev3dev
• https://goethereumbook.org/smart-contract-compile/