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ddr4s / fw / wiringPi / devLib / piFace.c @ 32:cadb9025f1e0

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/*
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 * piFace.:
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 *        This file to interface with the PiFace peripheral device which
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 *        has an MCP23S17 GPIO device connected via the SPI bus.
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 *
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 *        Copyright (c) 2012-2013 Gordon Henderson
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 ***********************************************************************
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 * This file is part of wiringPi:
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 *        https://projects.drogon.net/raspberry-pi/wiringpi/
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 *
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 *    wiringPi is free software: you can redistribute it and/or modify
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 *    it under the terms of the GNU Lesser General Public License as
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 *    published by the Free Software Foundation, either version 3 of the
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 *    License, or (at your option) any later version.
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 *
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 *    wiringPi is distributed in the hope that it will be useful,
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 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 *    GNU Lesser General Public License for more details.
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 *
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 *    You should have received a copy of the GNU Lesser General Public
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 *    License along with wiringPi.
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 *    If not, see <http://www.gnu.org/licenses/>.
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 ***********************************************************************
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 */
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#include <stdio.h>
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#include <stdint.h>
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#include <wiringPi.h>
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#include <mcp23s17.h>
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#include "piFace.h"
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/*
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 * myDigitalWrite:
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 *        Perform the digitalWrite function on the PiFace board
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 *********************************************************************************
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 */
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void myDigitalWrite (struct wiringPiNodeStruct *node, int pin, int value)
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{
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  digitalWrite (pin + 16, value) ;
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}
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/*
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 * myDigitalRead:
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 *        Perform the digitalRead function on the PiFace board
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 *        With a slight twist - if we read from base + 8, then we
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 *        read from the output latch...
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 *********************************************************************************
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 */
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int myDigitalRead (struct wiringPiNodeStruct *node, int pin)
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{
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  if ((pin - node->pinBase) >= 8)
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    return digitalRead (pin + 8) ;
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  else
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    return digitalRead (pin + 16 + 8) ;
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}
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/*
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 * myPullUpDnControl:
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 *        Perform the pullUpDnControl function on the PiFace board
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 *********************************************************************************
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 */
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void myPullUpDnControl (struct wiringPiNodeStruct *node, int pin, int pud)
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{
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  pullUpDnControl (pin + 16 + 8, pud) ;
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}
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/*
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 * piFaceSetup
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 *        We're going to create an instance of the mcp23s17 here, then
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 *        provide our own read/write routines on-top of it...
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 *        The supplied PiFace code (in Pithon) treats it as an 8-bit device
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 *        where you write the output ports and read the input port using the
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 *        same pin numbers, however I have had a request to be able to read
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 *        the output port, so reading 8..15 will read the output latch.
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 *********************************************************************************
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 */
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int piFaceSetup (const int pinBase)
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{
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  int    i ;
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  struct wiringPiNodeStruct *node ;
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// Create an mcp23s17 instance:
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   mcp23s17Setup (pinBase + 16, 0, 0) ;
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// Set the direction bits
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  for (i = 0 ; i < 8 ; ++i)
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  {
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    pinMode (pinBase + 16 +     i, OUTPUT) ;        // Port A is the outputs
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    pinMode (pinBase + 16 + 8 + i, INPUT) ;        // Port B inputs.
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  }
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  node = wiringPiNewNode (pinBase, 16) ;
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  node->digitalRead     = myDigitalRead ;
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  node->digitalWrite    = myDigitalWrite ;
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  node->pullUpDnControl = myPullUpDnControl ;
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  return 0 ;
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}