wiringPi_Blueberry/devLib/piFace.c

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2023-08-11 15:53:17 +08:00
/*
* piFace.:
* This file to interface with the PiFace peripheral device which
* has an MCP23S17 GPIO device connected via the SPI bus.
*
* Copyright (c) 2012-2013 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 <stdint.h>
#include <wiringPi.h>
#include <mcp23s17.h>
#include "piFace.h"
/*
* myDigitalWrite:
* Perform the digitalWrite function on the PiFace board
*********************************************************************************
*/
void myDigitalWrite (struct wiringPiNodeStruct *node, int pin, int value)
{
digitalWrite (pin + 16, value) ;
}
/*
* myDigitalRead:
* Perform the digitalRead function on the PiFace board
* With a slight twist - if we read from base + 8, then we
* read from the output latch...
*********************************************************************************
*/
int myDigitalRead (struct wiringPiNodeStruct *node, int pin)
{
if ((pin - node->pinBase) >= 8)
return digitalRead (pin + 8) ;
else
return digitalRead (pin + 16 + 8) ;
}
/*
* myPullUpDnControl:
* Perform the pullUpDnControl function on the PiFace board
*********************************************************************************
*/
void myPullUpDnControl (struct wiringPiNodeStruct *node, int pin, int pud)
{
pullUpDnControl (pin + 16 + 8, pud) ;
}
/*
* piFaceSetup
* We're going to create an instance of the mcp23s17 here, then
* provide our own read/write routines on-top of it...
* The supplied PiFace code (in Pithon) treats it as an 8-bit device
* where you write the output ports and read the input port using the
* same pin numbers, however I have had a request to be able to read
* the output port, so reading 8..15 will read the output latch.
*********************************************************************************
*/
int piFaceSetup (const int pinBase)
{
int i ;
struct wiringPiNodeStruct *node ;
// Create an mcp23s17 instance:
mcp23s17Setup (pinBase + 16, 0, 0) ;
// Set the direction bits
for (i = 0 ; i < 8 ; ++i)
{
pinMode (pinBase + 16 + i, OUTPUT) ; // Port A is the outputs
pinMode (pinBase + 16 + 8 + i, INPUT) ; // Port B inputs.
}
node = wiringPiNewNode (pinBase, 16) ;
node->digitalRead = myDigitalRead ;
node->digitalWrite = myDigitalWrite ;
node->pullUpDnControl = myPullUpDnControl ;
return 0 ;
}