93 lines
2.4 KiB
PHP
93 lines
2.4 KiB
PHP
<?php
|
|
|
|
/*
|
|
* Copyright (C) 2014, NoccyLabs
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>
|
|
*/
|
|
|
|
namespace NoccyLabs\Gpio\Bus;
|
|
|
|
class SoftwareSpiBus extends Bus
|
|
{
|
|
protected $buffer = null;
|
|
|
|
protected function configure()
|
|
{
|
|
$this->addPin("sclk");
|
|
$this->addPin("mosi");
|
|
$this->addPin("miso");
|
|
}
|
|
|
|
protected function spiExchangeByte($byte)
|
|
{
|
|
$in = 0;
|
|
if (is_string($byte)) { $byte = ord($byte); }
|
|
for($bit=0; $bit<8; $bit++) {
|
|
$this->setValue("sclk", 0);
|
|
$this->setValue("mosi", (($byte & 1<<$bit)>0));
|
|
usleep(5000);
|
|
$this->setValue("sclk", 1);
|
|
usleep(5000);
|
|
if ($this->getValue("miso")) {
|
|
$in |= 1<<$bit;
|
|
}
|
|
}
|
|
return chr($in);
|
|
}
|
|
|
|
protected function setValue($pin,$value)
|
|
{
|
|
echo "{$pin}→{$value}\n";
|
|
}
|
|
protected function getValue($pin)
|
|
{
|
|
echo "{$pin}←0\n";
|
|
return 0;
|
|
}
|
|
|
|
public function write($data)
|
|
{
|
|
for($n = 0; $n < strlen($data); $n++) {
|
|
$this->buffer .= $this->spiExchangeByte($data[$n]);
|
|
}
|
|
}
|
|
|
|
public function read($bytes)
|
|
{
|
|
$ret = null;
|
|
if (strlen($this->buffer)>0) {
|
|
if (strlen($this->buffer)<$bytes) {
|
|
$ret = $this->buffer;
|
|
$bytes -= strlen($this->buffer);
|
|
$this->buffer = null;
|
|
} else {
|
|
$ret = substr($this->buffer,0,$bytes);
|
|
$this->buffer = substr($this->buffer,$bytes);
|
|
return $ret;
|
|
}
|
|
}
|
|
for($n = 0; $n < $bytes; $n++) {
|
|
$ret.= $this->spiExchangeByte(0x00);
|
|
}
|
|
return $ret;
|
|
}
|
|
|
|
public function getBufferFill()
|
|
{
|
|
return strlen($this->buffer);
|
|
}
|
|
|
|
}
|