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78 lines
2.0 KiB
78 lines
2.0 KiB
/*
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*i2ctest.c
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* Raspberry Pi I2C test using wiringPi library.
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*
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*Copyright (c) Nahid Alam. <nahid.mahfuza.alam@gmail.com>
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***********************************************************
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*i2ctest 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 published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* i2ctest 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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***********************************************************
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*/
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#include <stdint.h>
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#include <stdio.h>
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#include <wiringPi.h>
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#include <wiringPiI2C.h>
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uint8_t solve_challenge(uint8_t arg) {
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return (arg >> 3);
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}
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uint8_t parse_int(const char *s) { // Convert string to hex
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uint8_t result = 0;
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int c;
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if ('0' == *s && 'x' == *(s + 1)) {
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s += 2;
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while (*s) {
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result = result << 4;
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if (c = (*s - '0'), (c >= 0 && c <= 9)) result |= c;
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else if (c = (*s - 'A'), (c >= 0 && c <= 5)) result |= (c + 10);
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else if (c = (*s - 'a'), (c >= 0 && c <= 5)) result |= (c + 10);
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else break;
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++s;
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}
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}
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return result;
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}
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int main(int argc, char *argv[]) {
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int fd; // Linux filehandle to the i2c device
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uint8_t challenge;
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uint8_t response;
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uint8_t i2c_addr;
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if (argc != 2) {
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printf("Usage: \n\ti2c_challenge <i2caddr>");
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return 1;
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}
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i2c_addr = parse_int(argv[1]);
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wiringPiSetup();
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fd = wiringPiI2CSetup(i2c_addr); // Initialize the i2c protocol with the address
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if (fd == -1) { // Failed to contact device
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printf("Can't setup the I2C device\n");
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return -1;
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}
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delay(1);
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challenge = wiringPiI2CRead(fd);
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printf("Received %d\n", challenge);
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response = solve_challenge(challenge);
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printf("Sending %d\n", response);
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delay(100);
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wiringPiI2CWrite(fd, (uint8_t)response);
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return 0;
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}
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