Sabas sabas1080

Guide to PROGMEM on ESP8266 and Arduino IDE

Intro

On low memory devices like the arduino and esp8266 you do not want strings to be stored in RAM. This occurs by default on these systems. Declare a string const char * xyz = "this is a string" and it will use up RAM.

The solution on these devices is to allow strings to be stored in read only memory, in Arduino this is the PROGMEM macro. Most of my experience is with the ESP8266 which is a 32bit micros controller. This device stores PROGMEM data in flash. The macro PROGMEM on ESP8266 is simply

#define PROGMEM   ICACHE_RODATA_ATTR

	/**
	* @author Mike Almond - @mikedotalmond
	*
	* Example sketch for working with the HC-SR04 Ultrasound distance sensor
	* http://users.ece.utexas.edu/~valvano/Datasheets/HCSR04b.pdf
	*
	* Uses a hardware interrupt to monitor the echo pin and measure the pulse length (without pausing code execution like you would when using Arduino::pulseIn())
	* https://github.com/mikedotalmond/arduino-pulseInWithoutDelay
	* PulseInZero uses interrupt 0 ( pin 2 on arduino uno)
	* PulseInOne uses interrupt 1 ( pin 3 on an arduino uno)

	#include <stdio.h>
	#include <stdlib.h>
	#include <math.h>
	/* run this program using the console pauser or add your own getch, system("pause") or input loop */
	int suma(int);
	int mult(int);
	void genera(int, int, int);
	int x,y,z,a,li,ls;

	from microbit import spi, sleep, pin16
	import array
	import gc

	class LoRa(object):
	"""
	Radio - LoRa. Single channel.
	"""

	def __init__(self, Frequency=434.450, Mode=1):

	// Copyright 2017-2018 Pavitra, All rights reserved
	// Released under the Apache License, Version 2.0
	// http://www.apache.org/licenses/LICENSE-2.0

	package com.pavitra;

	import android.content.Context;
	import android.util.Log;

	import com.physicaloid.lib.*;

	// Requires ws and screenshot-desktop

	const WebSocket = require('ws');
	const screenshot = require('screenshot-desktop')

	const wss = new WebSocket.Server({ port: 8889 });

	wss.on('connection', function connection(ws) {
	ws.on('message', function incoming(message) {
	console.log('received: %s', message);