Ahmad Fatoum

NAME

Device::HID - Perl Interface to HIDAPI

SYNOPSIS

    use Device::HID;
    use Data::Hexdumper;

    my $dev = Device::HID->new(vendor => 0x1337, product => 0x4242) or die "No such device!\n";
    $dev->timeout = 0.1;
    my $buf;
    while (defined (my $in = $dev->read_data($buf, $len)) {
        if ($in == 0) {
            print "Timeout!\n";
            next;
        }

        print Hexdumper($buf), "\n";
    }

METHODS AND ARGUMENTS

new()

Opens specified device and returns the corresponding object reference. Returns undef if an attempt to open the device has failed. Accepts following parameters:

vendor

Vendor ID.

product

Product ID.

serial

Device serial number. By default undefined.

autodie

if true, methods on this instance will use "croak" in Carp on failure. Default is 0, where undef is returned on failure.

read_data
    $dev->read_data($buffer, $size)
 

Reads data from the device (up to $size bytes) and stores it in $buffer.

Returns number of bytes read or 0 on timeout. Returns undef on error unless autodie is in effect.

timeout
    $dev->timeout = 0.1; # seconds (=100 ms)
    printf "Timeout is %d\n", $dev->timeout;
 

Lvalue subroutine that can be used to set and get the timeout in seconds for read_data. Granularity is 1 millisecond.

Default value is undef, which means wait indefinitely.

write_data
    $dev->write_data($reportid, $data)
 

Writes data to the device.

Returns actual number of bytes written or undef on error unless autodie is in effect.

autodie
    $dev->autodie = 1;
 

Lvalue subroutine that can be used to set whether the module "croak" in Carps on failure.

Default value is 0.

renew_on_timeout
    $dev->renew_on_timeout;
 

Closes HIDAPI handle and opens a new one transparently at read_data timeout and retries reading. When read_data returns successfully the first time, renew_on_timeout is reset and timeout is set to undef, but can be manually adjusted.

For reasons unknown to me, Valve's Steam controller needs a couple of hid_open calls before hid_read manages to read data. None of the prior hid_open calls fail, they just block indefinitely. For devices that ought to report periodically what they're up to, set the timeout in new to a sensible value and call renew_on_timeout on the handle. The following hid_read will then be retried till data can be read.

TODO

Use hid_error in croak/carp. Wrap the other information retrieval function. Till then, you can use the XSUBs in Device::HID::XS.

GIT REPOSITORY

http://github.com/athreef/Device-HID

SEE ALSO

Device::HID::XS

Alien::HIDAPI

The API of this module was modelled after Device::FTDI by Pavel Shaydo.

AUTHOR

Ahmad Fatoum <athreef@cpan.org>, http://a3f.at

COPYRIGHT AND LICENSE

Copyright (C) 2017 Ahmad Fatoum

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.