store a single var in flash and load at start

Hello,

I'm looking for to store a var in a permanent way (power off) and load at start (power on)
i saw that @Gordon implement a way to store data since 2v05, but the example code is for log datas (implementative way) and it seems a beat complex just for store a counter var.

have you a simple example to implement a counter (with a long type) storage over power-down?

I've tried

var memoire = require("Storage");
[...]
let NumPoemeEncours = memoire.read("num"); // numero encours
  if (NumPoemeEncours == null || NumPoemeEncours == undefined  || NumPoemeEncours == "") {
      NumPoemeEncours = 1;
      console.log("numero du poeme inconnu", memoire.read("num"));
      memoire.write("num",NumPoemeEncours);
      console.log("numero du poeme connu", memoire.read("num"));
  }
console.log("NumPoemeEncours:",NumPoemeE­ncours);

but it does not works!

what i'm doing wrong?

thanks for your time.

Sat 2021.09.11

Hi @Mrbbp has the example at been tried?

https://www.espruino.com/Data+Collection­#flash-memory

https://www.espruino.com/Reference#t_l_S­torage_write

Sat 2021.09.11

https://www.espruino.com/Reference#Stora­ge

Simple sample from above link:

var f = require("Storage");
f.write("a","Hello",0,14);
f.write("a"," ",5);
f.write("a","World!!!",6);
print(f.read("a")); // "Hello World!!!"

Add a counter:

var nCount = 0;

nCount++;

f.write("n",nCount.toString());
console.log("count is: ", f.read("n"));

nCount++;
nCount++;
nCount++;

f.write("n",nCount.toString());
console.log("count is: ", f.read("n"));

console.log(f.read("a"));

Now, type save() archiving that code block to permanent storage.

reset();

Reset device or power off / power on, then type in L-Hand console of WebIDE

console.log("count is: ", f.read("n"));

console.log(f.read("a"));

Output:

count is:  4
Hello World!!!
>

check Combining options

https://www.espruino.com/Saving

Thanks @Robin,
I started with the same example, but i missed the ‘toString()’ to convert my counter in String in my attempt.

It works now...

thanks again.

Regards