wiringPi_Blueberry/wiringPi/drcSerial.c
2023-08-11 15:53:17 +08:00

197 lines
5.0 KiB
C

/*
* drcSerial.c:
* Extend wiringPi with the DRC Serial protocol (e.g. to Arduino)
* Copyright (c) 2013-2016 Gordon Henderson
***********************************************************************
* This file is part of wiringPi:
* https://projects.drogon.net/raspberry-pi/wiringpi/
*
* wiringPi is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* wiringPi 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with wiringPi.
* If not, see <http://www.gnu.org/licenses/>.
***********************************************************************
*/
#include <stdio.h>
#include <time.h>
#include <string.h>
#include <errno.h>
#include "wiringPi.h"
#include "wiringSerial.h"
#include "drcSerial.h"
/*
* myPinMode:
* Change the pin mode on the remote DRC device
*********************************************************************************
*/
static void myPinMode (struct wiringPiNodeStruct *node, int pin, int mode)
{
/**/ if (mode == OUTPUT)
serialPutchar (node->fd, 'o') ; // Input
else if (mode == PWM_OUTPUT)
serialPutchar (node->fd, 'p') ; // PWM
else
serialPutchar (node->fd, 'i') ; // Default to input
serialPutchar (node->fd, pin - node->pinBase) ;
}
/*
* myPullUpDnControl:
* ATmegas only have pull-up's on of off. No pull-downs.
*********************************************************************************
*/
static void myPullUpDnControl (struct wiringPiNodeStruct *node, int pin, int mode)
{
// Force pin into input mode
serialPutchar (node->fd, 'i' ) ;
serialPutchar (node->fd, pin - node->pinBase) ;
/**/ if (mode == PUD_UP)
{
serialPutchar (node->fd, '1') ;
serialPutchar (node->fd, pin - node->pinBase) ;
}
else if (mode == PUD_OFF)
{
serialPutchar (node->fd, '0') ;
serialPutchar (node->fd, pin - node->pinBase) ;
}
}
/*
* myDigitalWrite:
*********************************************************************************
*/
static void myDigitalWrite (struct wiringPiNodeStruct *node, int pin, int value)
{
serialPutchar (node->fd, value == 0 ? '0' : '1') ;
serialPutchar (node->fd, pin - node->pinBase) ;
}
/*
* myPwmWrite:
*********************************************************************************
*/
static void myPwmWrite (struct wiringPiNodeStruct *node, int pin, int value)
{
serialPutchar (node->fd, 'v') ;
serialPutchar (node->fd, pin - node->pinBase) ;
serialPutchar (node->fd, value & 0xFF) ;
}
/*
* myAnalogRead:
*********************************************************************************
*/
static int myAnalogRead (struct wiringPiNodeStruct *node, int pin)
{
int vHi, vLo ;
serialPutchar (node->fd, 'a') ;
serialPutchar (node->fd, pin - node->pinBase) ;
vHi = serialGetchar (node->fd) ;
vLo = serialGetchar (node->fd) ;
return (vHi << 8) | vLo ;
}
/*
* myDigitalRead:
*********************************************************************************
*/
static int myDigitalRead (struct wiringPiNodeStruct *node, int pin)
{
serialPutchar (node->fd, 'r') ; // Send read command
serialPutchar (node->fd, pin - node->pinBase) ;
return (serialGetchar (node->fd) == '0') ? 0 : 1 ;
}
/*
* drcSetup:
* Create a new instance of an DRC GPIO interface.
* Could be a variable nunber of pins here - we might not know in advance
* if it's an ATmega with 14 pins, or something with less or more!
*********************************************************************************
*/
int drcSetupSerial (const int pinBase, const int numPins, const char *device, const int baud)
{
int fd ;
int ok, tries ;
time_t then ;
struct wiringPiNodeStruct *node ;
if ((fd = serialOpen (device, baud)) < 0)
return FALSE ;
delay (10) ; // May need longer if it's an Uno that reboots on the open...
// Flush any pending input
while (serialDataAvail (fd))
(void)serialGetchar (fd) ;
ok = FALSE ;
for (tries = 1 ; (tries < 5) && (!ok) ; ++tries)
{
serialPutchar (fd, '@') ; // Ping
then = time (NULL) + 2 ;
while (time (NULL) < then)
if (serialDataAvail (fd))
{
if (serialGetchar (fd) == '@')
{
ok = TRUE ;
break ;
}
}
}
if (!ok)
{
serialClose (fd) ;
return FALSE ;
}
node = wiringPiNewNode (pinBase, numPins) ;
node->fd = fd ;
node->pinMode = myPinMode ;
node->pullUpDnControl = myPullUpDnControl ;
node->analogRead = myAnalogRead ;
node->digitalRead = myDigitalRead ;
node->digitalWrite = myDigitalWrite ;
node->pwmWrite = myPwmWrite ;
return TRUE ;
}