转换MFRC522 UID十六进制字节到打印十进制 [英] Convert MFRC522 UID Hex Bytes to Printable Decimal
本文介绍了转换MFRC522 UID十六进制字节到打印十进制的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我用我的Arduino UNO的 MFRC522库阅读的Mifare RFID标签信息。
I'm using the MFRC522 library on my Arduino UNO to read Mifare RFID tag Info.
// Print HEX UID
Serial.print("Card UID:");
for (byte i = 0; i < mfrc522.uid.size; i++) {
Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
Serial.print(mfrc522.uid.uidByte[i], HEX);
}
Serial.println();
我有一个字节数组(4),其中包含HEX UID:
I've got a byte array(4) which contains the HEX UID:
54 C7 FD 5A
但我没把它转换为十进制:
But I've failed to convert it to Decimal:
HEX(5AFDC754) => DEC(1526581076)
我试着将字节数组转换为反向烧焦,但是编译器没有让我打印十二月
I've tried to convert the byte array to char reversely, but the compiler didn't let me print Dec.
char str[8];
int k = 0;
for (int i = 3; i >= 0 ; i -= 1) {
char hex[4];
snprintf(s, 4, "%x", mfrc522.uid.uidByte[i]);
for( int t = 0; t < 4; t++ ) {
if( (int)hex[t] != 0 )
str[t+k] = hex[t];
}
k+=2;
}
Serial.println( str, DEC);
任何建议是pciated AP $ P $
Any suggestion is appreciated
推荐答案
您将需要4个十六进制字节组合成一个无符号整数。
You will need to combine the 4 hex bytes into a single unsigned integer.
这取决于字节序(搜索它)。
This depends on Endianess (search for it).
有关大端:
unsigned int hex_num;
hex_num = uidByte[0] << 24;
hex_num += uidByte[1] << 16;
hex_num += uidByte[2] << 8;
hex_num += uidByte[3];
有关小端,反向uidByte位置的顺序。
For Little Endian, reverse the order of uidByte positions.
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