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@sticilface
sticilface / PROGMEM.md
Last active July 23, 2023 11:38
PROGMEM

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
@avafloww
avafloww / PhpJava.java
Last active June 13, 2024 07:36
This snippet of code is syntactically valid in both PHP and Java, and produces the same output in both.
/*<?php
//*/public class PhpJava { public static void main(String[] args) { System.out.printf("/*%s",
//\u000A\u002F\u002A
class PhpJava {
static function main() {
echo(//\u000A\u002A\u002F
"Hello World!");
}}
//\u000A\u002F\u002A
PhpJava::main();