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dcc_decode.c
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dcc_decode.c
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/***
BSD 2-Clause License
Copyright (c) 2018, Leo Bicknell
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
***/
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <pigpio.h>
/* Used for some internal array sizing. */
#define MAX_GPIOS 32
#define MAX_BITS 64
/* Timing values found via trial and error */
/* Remember, zeros s t r e t c h */
#define TICKS_MIN_DCC_ONE 12
#define TICKS_MAX_DCC_ONE 38
#define TICKS_MIN_DCC_ZERO 68
#define TICKS_MAX_DCC_ZERO 150
/* Refresh time aka how often to print summary status, as set by option r */
#define OPT_R_MIN 1
#define OPT_R_MAX 300
#define OPT_R_DEF 10
/* Sample time, as set by option s, more frequent sampling takes more CPU. The RPi 3 is easily
* good for 1 though, so we make that the default.
*/
#define OPT_S_MIN 1
#define OPT_S_MAX 10
#define OPT_S_DEF 1
/* Our Finite State Machine has two states. */
#define STATE_PREAMBLE 0
#define STATE_DATA 1
/* How many buckets in the timing data size array? This is used for debugging only. */
#define TIMING_DATA_SIZE 512
typedef struct {
uint32_t first_tick;
uint32_t last_high;
uint32_t curbit;
uint32_t state;
uint32_t preamble;
uint32_t dcc_one;
uint32_t dcc_zero;
uint32_t dcc_bad;
uint8_t bits[MAX_BITS];
} gpioData_t;
const char *two_eight_speeds[] = {
"STOP",
"E-STOP",
"Step 1",
"Step 3",
"Step 5",
"Step 7",
"Step 9",
"Step 11",
"Step 13",
"Step 15",
"Step 17",
"Step 19",
"Step 21",
"Step 23",
"Step 25",
"Step 27",
"STOP",
"E-STOP",
"Step 2",
"Step 4",
"Step 6",
"Step 8",
"Step 10",
"Step 12",
"Step 14",
"Step 16",
"Step 18",
"Step 20",
"Step 22",
"Step 24",
"Step 26",
"Step 28"
};
static int timing_data[TIMING_DATA_SIZE];
static volatile gpioData_t g_gpio_data[MAX_GPIOS];
static volatile gpioData_t l_gpio_data[MAX_GPIOS];
static volatile int g_reset_counts[MAX_GPIOS];
static uint32_t g_mask;
static int g_num_gpios;
static int g_gpio[MAX_GPIOS];
static int g_opt_r = OPT_R_DEF;
static int g_opt_s = OPT_S_DEF;
static int g_opt_t = 0;
static int g_opt_d = 0;
void usage()
{
fprintf(stderr,
"\n" \
"Usage: sudo ./dcc_decode gpio ... [OPTION] ...\n" \
" -t Print timing debug data\n" \
" -d Print dcc bits debug data\n" \
" -r value, sets report period in seconds (for -t and -d), %d-%d, default %d\n" \
" -s value, sets gpio sampling rate in micros, %d-%d, default %d\n" \
"\nEXAMPLE\n" \
"sudo ./dcc_decode 4 -r10 -s1\n" \
"Monitor gpio 4. Refresh every 0.1 seconds. Sample rate 1 micros.\n" \
"\n",
OPT_R_MIN, OPT_R_MAX, OPT_R_DEF,
OPT_S_MIN, OPT_S_MAX, OPT_S_DEF);
}
void fatal(int show_usage, char *fmt,...)
{
char buf[128];
va_list ap;
va_start(ap, fmt);
vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
fprintf(stderr, "%s\n", buf);
if (show_usage)
usage();
fflush(stderr);
exit(EXIT_FAILURE);
}
/* Parse command line options and set defaults. */
static int initOpts(int argc, char *argv[])
{
int i, opt;
while ((opt = getopt(argc, argv, "tdr:s:")) != -1) {
i = -1;
switch (opt) {
case 't':
g_opt_t = 1;
break;
case 'd':
g_opt_d = 1;
break;
case 'r':
i = atoi(optarg);
if ((i >= OPT_R_MIN) && (i <= OPT_R_MAX))
g_opt_r = i;
else
fatal(1, "invalid -r option (%d)", i);
break;
case 's':
i = atoi(optarg);
if ((i >= OPT_S_MIN) && (i <= OPT_S_MAX))
g_opt_s = i;
else
fatal(1, "invalid -s option (%d)", i);
break;
default: /* '?' */
usage();
exit(-1);
}
}
return optind;
}
/* Interrupt function called on each GPIO level change. */
void edges(int gpio, int level, uint32_t tick)
{
/* If the level just went high, record the timer value and return. */
if (level == 1) {
l_gpio_data[gpio].last_high = tick;
return;
}
/* If the level just went low, calculate the time of the last pulse. */
if (level == 0) {
/* Calculate time from the last rise, record in our statistics. */
uint32_t difference = tick - l_gpio_data[gpio].last_high;
if (difference < TIMING_DATA_SIZE) {
timing_data[difference]++;
} else {
/* Anything over the limit goes in the last bucket. */
timing_data[TIMING_DATA_SIZE - 1]++;
}
/* Have we gotten too many bits without seeing EOM? If so, we're reading garbage and it's
* time to reset.
*/
if (l_gpio_data[gpio].curbit >= MAX_BITS) {
printf("\nOverrun\n");
/* Reset everything */
l_gpio_data[gpio].state = STATE_PREAMBLE;
l_gpio_data[gpio].preamble = 0;
l_gpio_data[gpio].curbit = 0;
for (uint32_t x = 0; x < MAX_BITS; x++) {
l_gpio_data[gpio].bits[x] = 0;
}
return;
}
/* Is it in range to be a DCC ZERO? */
if (difference >= TICKS_MIN_DCC_ZERO && difference <= TICKS_MAX_DCC_ZERO) {
l_gpio_data[gpio].dcc_zero++;
/* Where are we in the FSM? */
switch (l_gpio_data[gpio].state) {
/* If we're in the preamble, see if it is still valid. */
case STATE_PREAMBLE:
/* More than 12 bits? Move to data state and record. */
if (l_gpio_data[gpio].preamble >= 12) {
l_gpio_data[gpio].state = STATE_DATA;
l_gpio_data[gpio].curbit++;
/* Not enough preamble, but we got a zero? That's an error, start over */
} else if (l_gpio_data[gpio].state == STATE_PREAMBLE) {
/* Reset everything */
l_gpio_data[gpio].state = STATE_PREAMBLE;
l_gpio_data[gpio].preamble = 0;
l_gpio_data[gpio].curbit = 0;
for (int x = 0; x < MAX_BITS; x++) {
l_gpio_data[gpio].bits[x] = 0;
}
}
break;
/* If we're in the data state, record the zero. */
case STATE_DATA:
l_gpio_data[gpio].curbit++;
break;
default:
/* Our FSM is in a state that should never happen, reset. */
printf("THIS SHOULD NEVER HAPPEN 1\n");
/* Reset everything */
l_gpio_data[gpio].state = STATE_PREAMBLE;
l_gpio_data[gpio].preamble = 0;
l_gpio_data[gpio].curbit = 0;
for (int x = 0; x < MAX_BITS; x++) {
l_gpio_data[gpio].bits[x] = 0;
}
}
/* Is it in range to be a DCC ONE? */
} else if (difference >= TICKS_MIN_DCC_ONE && difference <= TICKS_MAX_DCC_ONE) {
l_gpio_data[gpio].dcc_one++;
/* Where are we in the FSM? */
switch (l_gpio_data[gpio].state) {
/* If we're in the PREAMBLE state, count ones */
case STATE_PREAMBLE:
l_gpio_data[gpio].preamble++;
break;
/* If we're in the DATA state, record the data. */
case STATE_DATA:
/* Not the 9th bit? */
if (l_gpio_data[gpio].curbit % 9) {
/* Store */
l_gpio_data[gpio].bits[l_gpio_data[gpio].curbit / 9] |= 0x1 << (8 - (l_gpio_data[gpio].curbit % 9));
l_gpio_data[gpio].curbit++;
} else {
l_gpio_data[gpio].curbit++;
/* The current bit is a 9th bit, and it's a 1, end of the DCC message. Decode it! */
switch (l_gpio_data[gpio].curbit / 9) {
/* Two byte message + checksum. */
case 3:
if ((l_gpio_data[gpio].bits[0] ^ l_gpio_data[gpio].bits[1]) != l_gpio_data[gpio].bits[2]) {
printf("Checksum fails.\n");
}
if (l_gpio_data[gpio].bits[0] == 0x00 && l_gpio_data[gpio].bits[1] == 0x00) {
printf("DECODER RESET PACKET\n");
} else if (l_gpio_data[gpio].bits[0] == 0x00) {
/* I believe this should really be STOP and ESTOP, need to verify. */
printf("BROADCAST, direction %c, speed %s\n", l_gpio_data[gpio].bits[1] & 0x20 ? 'F' : 'B',
two_eight_speeds[l_gpio_data[gpio].bits[1] & 0x1F]);
} else if (l_gpio_data[gpio].bits[0] == 0xFF && l_gpio_data[gpio].bits[1] == 0x00) {
printf("IDLE PACKET\n");
} else {
printf("Baseline : 7-bit Address %4d, direction %c, speed (28ss) %s\n", l_gpio_data[gpio].bits[0],
l_gpio_data[gpio].bits[1] & 0x20 ? 'F' : 'B',
two_eight_speeds[l_gpio_data[gpio].bits[1] & 0x1F]);
}
break;
/* Three byte message + checksum. */
case 4:
if ((l_gpio_data[gpio].bits[0] ^ l_gpio_data[gpio].bits[1] ^ l_gpio_data[gpio].bits[2]) != l_gpio_data[gpio].bits[3]) {
printf("4-byte Checksum fails.\n");
break;
}
goto decode_packet;
/* Four byte message + checksum. */
case 5:
if ((l_gpio_data[gpio].bits[0] ^ l_gpio_data[gpio].bits[1] ^ l_gpio_data[gpio].bits[2] ^ l_gpio_data[gpio].bits[3]) != l_gpio_data[gpio].bits[4]) {
printf("5-byte Checksum fails.\n");
break;
}
goto decode_packet;
/* Five byte message + checksum. */
case 6:
if ((l_gpio_data[gpio].bits[0] ^ l_gpio_data[gpio].bits[1] ^ l_gpio_data[gpio].bits[2] ^ l_gpio_data[gpio].bits[3] ^ l_gpio_data[gpio].bits[4]) != l_gpio_data[gpio].bits[5]) {
printf("6-byte Checksum fails.\n");
break;
}
uint16_t address;
uint16_t address_bits;
uint16_t instructions;
decode_packet: /* Yes, there are two gotos above. */
/* Decode the address */
if ((l_gpio_data[gpio].bits[0] & 0xC0) == 0xC0) {
address = l_gpio_data[gpio].bits[1] | ((l_gpio_data[gpio].bits[0] & 0x3F) << 8);
address_bits = 14;
instructions = 2;
} else if ((l_gpio_data[gpio].bits[0] & 0xC0) == 0x80) {
address = l_gpio_data[gpio].bits[1] | ((l_gpio_data[gpio].bits[0] & 0x3F) << 8);
address_bits = 9;
instructions = 2;
} else if ((l_gpio_data[gpio].bits[0] & 0xC0) == 0x00) {
address = l_gpio_data[gpio].bits[0];
address_bits = 7;
instructions = 1;
}
printf("Extended(%d): %d-bit Address %4d:", l_gpio_data[gpio].curbit / 9, address_bits, address);
/* Rest of the packet is instructions, except for the last byte which is checksum */
for (int i = instructions; i < ((l_gpio_data[gpio].curbit / 9) - 1); i++) {
switch (l_gpio_data[gpio].bits[i] & 0xE0) {
/* 000 Decoder and Consisit Control Instruction */
case 0x00:
switch (l_gpio_data[gpio].bits[i] & 0x10) {
case 0x00: /* Decoder Control */
switch (l_gpio_data[gpio].bits[i] & 0x0E) {
case 0x00: /* Digital Decoder Reset */
printf(" DECODER FACTORY RESET");
break;
case 0x02: /* Factory Test */
printf(" DECODER FACTORY TEST");
break;
case 0x04: /* Reserved */
printf(" Decoder Control Reserved 0x04");
break;
case 0x06: /* Set Decoder Flags */
printf(" Set decoder flags:");
switch(l_gpio_data[gpio].bits[i+1] & 0xF0) {
case 0x00: /* Disable 111 instructions */
printf(" Subaddress %d Disable 111 Instructions", l_gpio_data[gpio].bits[i+1] & 0x07);
break;
case 0x40: /* Disable Decoder Acknowledgement Request Instruction */
printf(" Subaddress %d Disable Decoder Acknowledgement Request", l_gpio_data[gpio].bits[i+1] & 0x07);
break;
case 0x50: /* Activate Bi-Directional Communications */
printf(" Subaddress %d Activate Bi-Directional Communications", l_gpio_data[gpio].bits[i+1] & 0x07);
break;
case 0x80: /* Set Bi-Directional Communications */
printf(" Subaddress %d Set Bi-Directional Communications", l_gpio_data[gpio].bits[i+1] & 0x07);
break;
case 0x90: /* Set 111 Instruction */
printf(" Subaddress %d Enable 111 Instruction", l_gpio_data[gpio].bits[i+1] & 0x07);
break;
case 0xF0: /* Accept 111 Instructions */
printf(" Subaddress %d Accept 111 Instruction", l_gpio_data[gpio].bits[i+1] & 0x07);
break;
}
i++;
break;
case 0x08: /* Reserved */
printf(" Decoder Control Reserved 0x08");
break;
case 0x0A: /* Set Advanced Addressing */
printf(" Set advanced addressing.");
break;
case 0x0C: /* Reserved */
printf(" Decoder Control Reserved 0x0C");
break;
case 0x0E: /* Decoder Acknowledgement Request */
printf(" Request decoder acknowledgement.");
break;
}
break;
case 0x10: /* Consist Control */
switch (l_gpio_data[gpio].bits[i] & 0x0F) {
case 0x00: /* Deactivate */
printf(" deactivate consist %d", l_gpio_data[gpio].bits[i + 1]);
break;
case 0x02: /* Activate Normal Direction */
printf(" %sactivate consist normal direction %d", l_gpio_data[gpio].bits[i + 1] == 0 ? "de" : "",
l_gpio_data[gpio].bits[i + 1]);
break;
case 0x03: /* Activate Reverse Direction */
printf(" %sactivate consist reverse direction %d", l_gpio_data[gpio].bits[i + 1] == 0 ? "de" : "",
l_gpio_data[gpio].bits[i + 1]);
break;
}
}
i++;
break;
/* 001 Advanced Operations Instructions */
case 0x20:
switch (l_gpio_data[gpio].bits[i] & 0x1F) {
case 0x1F: /* 128 Speed Step Control */
if ((l_gpio_data[gpio].bits[i + 1] & 0x7F) == 0) {
printf(" direction %c, speed (128ss) STOP", l_gpio_data[gpio].bits[i + 1] & 0x80 ? 'F' : 'R');
} else if ((l_gpio_data[gpio].bits[i + 1] & 0x7F) == 1) {
printf(" direction %c, speed (128ss) E-STOP", l_gpio_data[gpio].bits[i + 1] & 0x80 ? 'F' : 'R');
} else {
printf(" direction %c, speed (128ss) %d",
l_gpio_data[gpio].bits[i + 1] & 0x80 ? 'F' : 'R', l_gpio_data[gpio].bits[i + 1] & 0x7F);
}
i++;
break;
case 0x1E: /* Restricted Speed Step Control */
printf(" restricted speed step");
i++;
break;
case 0x1D: /* Analog Function Group */
printf(" analog function group");
i++;
break;
default:
printf("Instruction reserved for future use [%x]\n", l_gpio_data[gpio].bits[i] & 0x1F);
}
i++;
break;
/* 010 Speed and Direction Instruction for Reverse Operation */
case 0x40:
printf(" direction R, speed (28ss) %s", two_eight_speeds[l_gpio_data[gpio].bits[i] & 0x1F]);
break;
/* 011 Speed and Direction Instruction for Forward Operation */
case 0x60:
printf(" direction F, speed (28ss) %s", two_eight_speeds[l_gpio_data[gpio].bits[i] & 0x1F]);
break;
/* 100 Function Group One Instruction */
case 0x80:
printf(" F0=%c, F1=%c, F2=%c, F3=%c, F4=%c",
(l_gpio_data[gpio].bits[i] & 0x10) == 0x10 ? '1' : '0',
(l_gpio_data[gpio].bits[i] & 0x01) == 0x01 ? '1' : '0',
(l_gpio_data[gpio].bits[i] & 0x02) == 0x02 ? '1' : '0',
(l_gpio_data[gpio].bits[i] & 0x04) == 0x04 ? '1' : '0',
(l_gpio_data[gpio].bits[i] & 0x08) == 0x08 ? '1' : '0');
break;
/* 101 Function Group Two Instruction */
case 0xA0:
printf(" F5=%c, F6=%c, F7=%c, F8=%c, F9=%c, F10=%c, F11=%c, F12=%c",
(l_gpio_data[gpio].bits[i] & 0x11) == 0x11 ? '1' : '0',
(l_gpio_data[gpio].bits[i] & 0x12) == 0x12 ? '1' : '0',
(l_gpio_data[gpio].bits[i] & 0x14) == 0x14 ? '1' : '0',
(l_gpio_data[gpio].bits[i] & 0x18) == 0x18 ? '1' : '0',
(l_gpio_data[gpio].bits[i] & 0x01) == 0x01 ? '1' : '0',
(l_gpio_data[gpio].bits[i] & 0x02) == 0x02 ? '1' : '0',
(l_gpio_data[gpio].bits[i] & 0x04) == 0x04 ? '1' : '0',
(l_gpio_data[gpio].bits[i] & 0x08) == 0x08 ? '1' : '0');
break;
/* 110 Future Expansion */
case 0xC0:
printf(" Future Expansion");
break;
/* 111 Configuration Variable Access Instruction */
case 0xE0:
switch (l_gpio_data[gpio].bits[i] & 0x10) {
case 0x00: /* All */
switch (l_gpio_data[gpio].bits[i] & 0xC0) {
case 0x00: /* Reserved */
case 0x40: /* Verify Byte */
printf(" Verify CV %d=%d", ((l_gpio_data[gpio].bits[i] & 0x3) << 8) + l_gpio_data[gpio].bits[i+1], l_gpio_data[gpio].bits[i+2]);
break;
case 0x80: /* Write Byte */
printf(" Write CV %d=%d", ((l_gpio_data[gpio].bits[i] & 0x3) << 8) + l_gpio_data[gpio].bits[i+1], l_gpio_data[gpio].bits[i+2]);
break;
case 0xC0: /* Bit Manipulation */
switch (l_gpio_data[gpio].bits[i+2] & 0x10) {
case 0x00: /* Verify Bit */
printf(" Verify CV %d bit %d value %d", ((l_gpio_data[gpio].bits[i] & 0x3) << 8) + l_gpio_data[gpio].bits[i+1], l_gpio_data[gpio].bits[i+2] & 0x7, l_gpio_data[gpio].bits[i+2] & 0x8 >> 3);
break;
case 0x10: /* Write Bit */
printf(" Verify CV %d bit %d value %d", ((l_gpio_data[gpio].bits[i] & 0x3) << 8) + l_gpio_data[gpio].bits[i+1], l_gpio_data[gpio].bits[i+2] & 0x7, l_gpio_data[gpio].bits[i+2] & 0x8 >> 3);
break;
}
break;
}
i++; i++;
break;
case 0x10: /* Limited */
switch (l_gpio_data[gpio].bits[i] & 0xF) {
case 0x00: /* Not available */
printf(" Configuration Variable Short Form Instruction Not Available");
break;
case 0x02: /* CV#23 Acceleration Value */
printf(" Set CV23=%d", l_gpio_data[gpio].bits[i+1]);
break;
case 0x03: /* CV#24 Acceleration Value */
printf(" Set CV24=%d", l_gpio_data[gpio].bits[i+1]);
break;
case 0x09: /* S-9.2.3 Appendix B */
printf(" Configuration Variable S-9.2.3 Appendix B");
break;
}
i++;
break;
}
break;
default:
printf("Unhandled case [%x]", l_gpio_data[gpio].bits[i]);
}
}
printf("\n");
break;
default:
/* We did not know how to decode, print packet in hex */
printf("%d bytes:", l_gpio_data[gpio].curbit / 9);
/* 9th byte 1 means end packet */
for (uint32_t x = 0; x < l_gpio_data[gpio].curbit / 9; x++) {
printf(" %02X", l_gpio_data[gpio].bits[x]);
}
putchar('\n');
}
/* Message has been parsed, reset everything. */
l_gpio_data[gpio].state = STATE_PREAMBLE;
l_gpio_data[gpio].preamble = 0;
l_gpio_data[gpio].curbit = 0;
for (uint32_t x = 0; x < MAX_BITS; x++) {
l_gpio_data[gpio].bits[x] = 0;
}
}
break;
default:
/* The state variable didn't match one of our FSM states! Reset everything and hope
* we can restart. */
printf("FSM in an unknown state %d.\n", l_gpio_data[gpio].state);
/* Reset everything */
l_gpio_data[gpio].state = STATE_PREAMBLE;
l_gpio_data[gpio].preamble = 0;
l_gpio_data[gpio].curbit = 0;
for (uint32_t x = 0; x < MAX_BITS; x++) {
l_gpio_data[gpio].bits[x] = 0;
}
}
/* Was not in range to be a DCC zero or one, record as a bad interval and start over. */
} else {
l_gpio_data[gpio].dcc_bad++;
/* printf("Ticks not in valid range, got %d.\n", difference); */
/* Reset everything */
l_gpio_data[gpio].state = STATE_PREAMBLE;
l_gpio_data[gpio].preamble = 0;
l_gpio_data[gpio].curbit = 0;
for (int x = 0; x < MAX_BITS; x++) {
l_gpio_data[gpio].bits[x] = 0;
}
}
}
}
/* Program entry point. */
int main(int argc, char *argv[])
{
int i, rest, g, mode;
/* Parse command line paramters. */
rest = initOpts(argc, argv);
/* Set our GPIO counter to zero. */
g_num_gpios = 0;
/* Loop through the left over command line arguments, assume they are GPIO numbers to monitor. */
for (i = rest; i < argc; i++) {
g = atoi(argv[i]);
if ((g >= 0) && (g < 32)) {
g_gpio[g_num_gpios++] = g;
g_mask |= (1 << g);
} else {
fatal(1, "%d is not a valid g_gpio number\n", g);
}
}
if (!g_num_gpios) {
fatal(1, "At least one gpio must be specified");
}
/* Print out a summary of what we're monitoring and the paramters. */
printf("Monitoring gpios");
for (i = 0; i < g_num_gpios; i++) {
printf(" %d", g_gpio[i]);
}
printf("\nSample rate %d micros, refresh rate %d deciseconds\n", g_opt_s, g_opt_r);
/* Set the PiGPIO library timer based on the user's input. */
gpioCfgClock(g_opt_s, 1, 1);
/* Initialize the PiGPIO library. */
if (gpioInitialise() < 0) {
return 1;
}
/* Configure the PiGPIO library to mointor g_gpio level changes */
mode = PI_INPUT;
for (i = 0; i < g_num_gpios; i++) {
gpioSetAlertFunc(g_gpio[i], edges);
gpioSetMode(g_gpio[i], mode);
}
/* Wait around forever, as the PiGPIO stuff is interrupt driven. */
while (1) {
/* Every opt-r * 1000000 ticks report status */
gpioDelay(g_opt_r * 1000000);
/* ...once for each GPIO being monitored. */
for (i = 0; i < g_num_gpios; i++) {
g = g_gpio[i];
g_gpio_data[g] = l_gpio_data[g];
/* Print timing data if the user requested. */
if (g_opt_t) {
printf("DEBUG: Timing Data Dump Follows\n");
for (int x = 0;x < 512;x++) {
printf("DEBUG: ticks=%d\t%d\n", x, timing_data[x]);
}
}
/* If the user requested, print how many DCC symbols we received and reset their counters. */
if (g_opt_d) {
if (g_gpio_data[g].dcc_one > 0 || g_gpio_data[g].dcc_zero > 0) {
printf("DEBUG: GPIO %d: %8d dcc ones, %8d dcc zeros, %8d unparseable intervals\n", g, g_gpio_data[g].dcc_one,
g_gpio_data[g].dcc_zero, g_gpio_data[g].dcc_bad);
}
l_gpio_data[g].dcc_one = 0;
l_gpio_data[g].dcc_zero = 0;
l_gpio_data[g].dcc_bad = 0;
}
}
}
/* We currently have no way to get here... */
gpioTerminate();
}