Converting bytes from device to decimal in Perl-CodePudding

I am trying to follow this tutorial: https://cylab.be/blog/92/measure-ambient-temperature-with-temper-and-linux to get the TEMPer USB sensor to measure ambient temperature so that I can incorporate it into a Perl script that alerts me of a room's ambient temperature. In the tutorial's example they convert the following bytes of data from the device:

Response from device (8 bytes):
     80 80 0b 92   4e 20 00 00

to:

In the response, the Bytes 3 and 4 (so 0b 92) indicate the ambient temperature:

0b 92 converted into decimal is 2932
2932 divided by 100 is 29.32 C

Does anyone know how I can use Perl to translate such bytes of data to a decimal and thus to celsius temperature?

CodePudding user response：

Perl's hex function can translate hexadecimal numbers in text to Perl numbers, which you can then represent any way that you like:

my $string = '0b92';
my $number = hex($string);
print $number;  # 2962

But, it sounds like you may be reading raw data from a device, and that the number you want is in two octets. Read those and turn them into a Perl number with unpack (with the appropriate format that respects the octet order):

my $buffer;
read $fh, $buffer, 2;
my $number = unpack 'S>', $buffer;