Module mfrc522 RFID

[salarizadi]

Hello.

Is there a ready code to use the MFRC522 module for ESP32 ModdableSDK?

[phoddie]

Not that I'm aware of. NFC support would be great. I know @andycarle has given some thought to how that could fit into the ECMA-419 sensor / peripheral class patterns.

[salarizadi]

@phoddie

Sorry for not being able to upload the code quickly enough. I ran into several problems. It is really a heavy project and I did not expect it to be so heavy.

How can I: send this array of hexadecimal houses to C and get the correct output from there?

JavaScript example:

const keys  = [
    0xFF, 0xFF, 0xFF,
    0xFF, 0xFF, 0xFF
];

class MFRC522 {
   _write ( block, data ) @ "xs_mfrc522_write";
    write ( block, data ) {
        if ( !Array.isArray(data) )
            trace("<error>MFRE522 write : data not is array");
        data = new Uint8Array(data).buffer;
        return this._write(block, data)
    }
}

Sample C:

MIFARE_Key key;
char *keys = xsmcToArrayBuffer(xsArg(2)); // Keys

for (int i = 0; i < sizeof(keys); i++)
        key.keyByte[i] = keys[i];

...

xsmcSetInteger(xsResult, PCD_Authenticate(MFRC522_SPI, cmd_k, block, &key, &uid));

If I solve this problem faster, the MFRC522 module will be uploaded in 24 hours

Thank you.

[phoddie]

If I understand correctly, your JavaScript write function accepts an Array. You want to treat that as an array of bytes in the native code. To do that, you can pass the Array through to the native code directly. I think that will be simpler and at least as efficient:

class MFRC522 {
    write ( block, data ) @ "xs_mfrc522_write";
}

In C, you can access the array elements directly:

xsmcVars(1);
xsmcGet(xsVar(0), xsArg(1), xsID_length);  // get the length property of argument 1
int length = xsmcToInteger(xsVar(0));  // get the value of the length property as an integer
int i;
for (i = 0; i < length; i++) {
   xsmcGetIndex(xsVar(0), xsArg(1), i); // get element i of array in argument 1
   uint8_t byte = (uint8_t)xsmcToInteger(xsVar(0));  // get value of element as integer
   key.keyByte[i] = byte;
}

[salarizadi]

@phoddie It worked correctly! Thankful

[salarizadi]

@phoddie

What should I do if I want to add to a hexadecimal array and display it as hex? This example I wrote only shows the number:

Uid *cardID = &uid;

xsmcVars(1);

xsResult = xsmcNewArray(0);
for (int i = 0; i < cardID->size; i++) {
     xsVar(0) = xsInteger(cardID->uidByte[i]);
     xsmcSetIndex(xsResult, i, xsVar(0));
     printf("\n uid : %x", cardID->uidByte[i]);
}

Result : [131,79,152,30]

I want to show it like this : [83,4f,98,1e]

And if I want to add this array to a key in the object, like:

trace(mfrc522.info())

{
  "id" : [83,4f,98,1e],
  "type": ...,
  ....
}

What should I do

note : These items are for returning RFID card information in the form of objects

[phoddie]

You can easily return an ArrayBuffer with a copy of a block of native memory. Please see the blog post "Best Practices for Accessing Memory Buffers from Native Code" specifically in the section "Creating a Buffer".