gavrilyak

I/O class pattern

Copyright 2018 Moddable Tech, Inc.
Peter Hoddie
Patrick Soquet
Updated December 17, 2018

Overview

The I/O class pattern is designed to be applied to many different interfaces. These include digital, analog input, SPI, I2C, serial, TCP socket, UDP socket, etc. Each of these defines a class pattern for the interface (e.g. a Digital class pattern) that is a logical subclass of the I/O class pattern.

The I/O class pattern assumes read and write operations will not block for significant periods of time (this is deliberately not quantified). The model for this is non-blocking network sockets.

Description

Enable i2c RTC using systemd. A udev rules triggers an I2C systemd service on I2C kernel module adding. Service then loads I2C driver adding a new I2C device to /sys Then kernel loads I2C RTC driver and adds an RTC device It triggers a udev rules that updates hardware clock

Application on raspberry pi

Enable I2C

enable I2C in config.txt, adding device_tree_param=i2c1=on

	module.exports = {
	promisify: function (web3) {
	// Pipes values from a Web3 callback.
	var callbackToResolve = function (resolve, reject) {
	return function (error, value) {
	if (error) {
	reject(error);
	} else {
	resolve(value);
	}

	/**
	* Base contract that all upgradeable contracts should use.
	*
	* Contracts implementing this interface are all called using delegatecall from
	* a dispatcher. As a result, the _sizes and _dest variables are shared with the
	* dispatcher contract, which allows the called contract to update these at will.
	*
	* _sizes is a map of function signatures to return value sizes. Due to EVM
	* limitations, these need to be populated by the target contract, so the
	* dispatcher knows how many bytes of data to return from called functions.

	const store = createStore((state = { counter: 0 }, action) => {
	switch(action.type) {
	case "INCREMENT":
	return { counter: state.counter + 1 }
	case "DECREMENT":
	return { counter: state.counter - 1 }
	default:
	return state
	}
	})