128 lines
3.4 KiB
C
128 lines
3.4 KiB
C
/*
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=================================================================================
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Name : i2c-arduino.c
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Version : 0.1
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Copyright (C) 2012 by Andre Wussow, 2012, desk@binerry.de
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Description :
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Sample of controlling an Arduino connected to Raspberry Pi via I2C.
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Recommended connection (http://www.raspberrypi.org/archives/384):
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Arduino pins I2C-Shifter Raspberry Pi
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GND P06 - GND
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5V 5V
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SDA SDA2
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SCL SCL2
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3V3 P01 - 3.3V
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SDA1 P03 - SDA
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SCL1 P05 - SCL
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References :
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http://binerry.de/post/27128825416/raspberry-pi-with-i2c-arduino-slave
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================================================================================
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This sample is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This sample 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 GNU
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Lesser General Public License for more details.
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================================================================================
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*/
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#include <fcntl.h>
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#include <linux/i2c-dev.h>
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#include <linux/i2c.h>
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#include <stdio.h>
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#include <unistd.h>
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int deviceHandle;
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int readBytes;
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char buffer[7];
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void testCommand(char command[3], char identifier[5]);
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int main (void)
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{
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// print infos
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printf("Raspberry Pi I2C Arduino Sample\n");
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printf("========================================\n");
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// initialize buffer
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buffer[0] = 0x00;
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// address of i2c Arduino device
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int deviceI2CAddress = 0x2A; // (0x2A = 42)
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// open device on /dev/i2c-0
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if ((deviceHandle = open("/dev/i2c-0", O_RDWR)) < 0) {
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printf("Error: Couldn't open device! %d\n", deviceHandle);
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return 1;
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}
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// connect to arduino as i2c slave
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if (ioctl(deviceHandle, I2C_SLAVE, deviceI2CAddress) < 0) {
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printf("Error: Couldn't find arduino on address!\n");
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return 1;
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}
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// begin transmission and request acknowledgement
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readBytes = write(deviceHandle, buffer, 1);
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if (readBytes != 1)
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{
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printf("Error: Received no ACK-Bit, couldn't established connection!");
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}
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else
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{
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// drive some tests
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testCommand("L11", "LED1 on");
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usleep(2000000); // 2s
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testCommand("L10", "LED1 off");
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usleep(2000000); // 2s
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testCommand("L21", "LED2 on");
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usleep(2000000); // 2s
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testCommand("L20", "LED2 off");
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usleep(2000000); // 2s
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testCommand("L31", "LED3 on");
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usleep(2000000); // 2s
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testCommand("L30", "LED3 off");
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usleep(2000000); // 2s
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testCommand("R11", "Relay on");
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usleep(2000000); // 2s
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testCommand("R10", "Relay off");
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}
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// close connection and return
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close(deviceHandle);
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return 0;
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}
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// function for testing command
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void testCommand(char command[3], char action[10])
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{
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// switch on
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printf("Switching %s ... ", action);
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readBytes = write(deviceHandle, command, 3);
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// give arduino some reaction time
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usleep(100000); // 100ms
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// read success
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readBytes = read(deviceHandle, buffer, 1);
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if (readBytes != 1)
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{
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printf("Error: Received no data!");
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}
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else
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{
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// check response: 0 = error / 1 = success
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if (buffer[0] == 1)
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{
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printf("OK!\n");
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}
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}
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} |