NAME
RPi::SPI - Communicate with devices over the Serial Peripheral Interface
(SPI) bus on Raspberry Pi
SYNOPSIS
my $channel = 0;
my $spi = RPi::SPI->new($channel);
my $buf = [0x01, 0x02];
my $len = 2;
$buf = $spi->rw($buf, $len);
# write occurs, then a read, and the read buffer overwrites the
# write TX buffer, so the read data is in the write buffer after the call
print "$_\n" for @$buf;
DESCRIPTION
This distribution provides you the ability to communicate with devices
attached to the channels on the Serial Peripheral Interface (SPI) bus.
Although it was designed for the Raspberry Pi, that's not a hard
requirement, and it should work on any Unix-type system that has support
for SPI.
METHODS
new
Instantiates a new RPi::SPI instance, prepares a specific SPI bus
channel for use, then returns the object.
Parameters:
The SPI bus channel to initialize.
Mandatory: Integer, `0' for `/dev/spidev0.0' or `1' for
`/dev/spidev0.1'.
Optional, Integer. The data rate to communicate on the bus
using. Defaults to `1000000' (1MHz).
Dies if we can't open the SPI bus.
rw
Writes specified data to the bus on the channel specified in
`new()', then after completion, does a read of the bus and
re-populates the write buffer with the freshly read data.
Parameters:
Mandatory: Array reference where each element is an unsigned
char (0-255). This array is the write buffer; the data we'll
be sending to the SPI bus.
Mandatory: Integer, the number of array elements in the
`$buf' parameter sent in above.
Return: The write buffer, after being re-populated with
the read data.
Dies if we can't open the SPI bus.
AUTHOR
Steve Bertrand, `<steveb at cpan.org>'
LICENSE AND COPYRIGHT
Copyright 2017 Steve Bertrand.
This program is free software; you can redistribute it
and/or modify it under the terms of either: the GNU
General Public License as published by the Free Software
Foundation; or the Artistic License.
See
http://dev.perl.org/licenses/ for more information.
