I have almost zero experience with coding, and I'm needing some help..
I managed to piece together code from thanks to google to do most of what I want, but I'm missing steps..
I have this code from Brad's blog, that works just fine, but I need to add to it the ability to put the data in a mysql database, not print it to the screen..
#include <stdio.h>
#include <dirent.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
// struct to hold ds18b20 data for linked list
struct ds18b20 {
char devPath[128];
char devID[16];
char tempData[6];
struct ds18b20 *next;
};
// Find connected 1-wire devices. 1-wire driver creates entries for each device
// in /sys/bus/w1/devices on Beaglebone Black. Create linked list.
int8_t findDevices(struct ds18b20 *d) {
DIR *dir;
struct dirent *dirent;
struct ds18b20 *newDev;
char path[] = "/sys/bus/w1/devices";
int8_t i = 0;
dir = opendir(path);
if (dir != NULL)
{
while ((dirent = readdir(dir))) {
// 1-wire devices are links beginning with 28-
if (dirent->d_type == DT_LNK &&
strstr(dirent->d_name, "28-") != NULL) {
newDev = malloc( sizeof(struct ds18b20) );
strcpy(newDev->devID, dirent->d_name);
// Assemble path to OneWire device
sprintf(newDev->devPath, "%s/%s/w1_slave", path, newDev->devID);
i++;
newDev->next = 0;
d->next = newDev;
d = d->next;
}
}
(void) closedir(dir);
}
else
{
perror ("Couldn't open the w1 devices directory");
return 1;
}
return i;
}
int8_t readTemp(struct ds18b20 *d) {
while(d->next != NULL){
d = d->next;
int fd = open(d->devPath, O_RDONLY);
if(fd == -1)
{
perror ("Couldn't open the w1 device.");
return 1;
}
char buf[256];
ssize_t numRead;
while((numRead = read(fd, buf, 256)) > 0) {
strncpy(d->tempData, strstr(buf, "t=") + 2, 5);
float tempC = strtof(d->tempData, NULL);
printf("Device: %s - ", d->devID);
printf("Temp: %.3f C ", tempC / 1000);
printf("%.3f F\n\n", (tempC / 1000) * 9 / 5 + 32);
}
close(fd);
}
return 0;
}
int main (void) {
struct ds18b20 *rootNode;
struct ds18b20 *devNode;
// Load pin configuration. Ignore error if already loaded
system("echo BB-W1 > /sys/devices/bone_capemgr.9/slots 2>/dev/null");
while(1) {
rootNode = malloc( sizeof(struct ds18b20) );
devNode = rootNode;
int8_t devCnt = findDevices(devNode);
printf("\nFound %d devices\n\n", devCnt);
readTemp(rootNode);
// Free linked list memory
while(rootNode) {
// Start with current value of root node
devNode = rootNode;
// Save address of next devNode to rootNode before deleting current devNode
rootNode = devNode->next;
// Free current devNode.
free(devNode);
}
// Now free rootNode
free(rootNode);
}
return 0;
}
I also have code that fakes temp readings and adds them to the database, but I'm lost on how to modify that code to take real readings as the author was using an older temp sensor.
