Difference between revisions of "Temp sens.c"
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| + | Grab hold of a "Microchip TC74" temperature sensor IC, a TO220 is easy to handle, and hook it up to the bus using the pins as shown in the hardware hack section. Make sure you use a 3.3v part. | ||
| + | |||
* http://ww1.microchip.com/downloads/en/devicedoc/21462c.pdf | * http://ww1.microchip.com/downloads/en/devicedoc/21462c.pdf | ||
| + | |||
| + | |||
| + | <code><pre> | ||
| + | // Temp Sensor Talkies - Andrew Armstrong 2007 | ||
| + | |||
| + | #include <stdio.h> | ||
| + | #include <fcntl.h> | ||
| + | #include <sys/ioctl.h> | ||
| + | |||
| + | |||
| + | #define I2C_DEVICE "/dev/i2c/0" | ||
| + | #define I2C_SLAVE 0x0703 | ||
| + | |||
| + | // Write to I2c | ||
| + | |||
| + | int i2c_read (int slaveaddr, unsigned char *buffer, int length) | ||
| + | { | ||
| + | int i2c_fd; | ||
| + | int red; | ||
| + | |||
| + | if( (i2c_fd = open( I2C_DEVICE, O_RDWR)) < 0) | ||
| + | { | ||
| + | printf( "Unable to open the i2c port!\n"); | ||
| + | return 100; | ||
| + | } | ||
| + | |||
| + | if( ioctl( i2c_fd, I2C_SLAVE, slaveaddr) == -1) | ||
| + | { | ||
| + | close( i2c_fd); | ||
| + | printf( "Unable to setup the i2c port!\n"); | ||
| + | return 101; | ||
| + | } | ||
| + | |||
| + | red=read( i2c_fd, buffer, length); | ||
| + | |||
| + | close( i2c_fd); | ||
| + | |||
| + | return 0; | ||
| + | } | ||
| + | |||
| + | //Whats the temperature | ||
| + | |||
| + | void printtemp() | ||
| + | { | ||
| + | char dbuff[2]; | ||
| + | |||
| + | //***TEMPERATURE | ||
| + | |||
| + | i2c_read (0x48, dbuff, 1); | ||
| + | |||
| + | printf ("Temperature :- %d degrees C\n", dbuff[0]); | ||
| + | } | ||
| + | |||
| + | int main(void) | ||
| + | { | ||
| + | printtemp(); | ||
| + | |||
| + | return 0; | ||
| + | |||
| + | } | ||
| + | |||
| + | |||
| + | </pre></code> | ||
| + | |||
| + | [[Category:Software]] | ||
Latest revision as of 19:10, 10 February 2008
Grab hold of a "Microchip TC74" temperature sensor IC, a TO220 is easy to handle, and hook it up to the bus using the pins as shown in the hardware hack section. Make sure you use a 3.3v part.
// Temp Sensor Talkies - Andrew Armstrong 2007
#include <stdio.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#define I2C_DEVICE "/dev/i2c/0"
#define I2C_SLAVE 0x0703
// Write to I2c
int i2c_read (int slaveaddr, unsigned char *buffer, int length)
{
int i2c_fd;
int red;
if( (i2c_fd = open( I2C_DEVICE, O_RDWR)) < 0)
{
printf( "Unable to open the i2c port!\n");
return 100;
}
if( ioctl( i2c_fd, I2C_SLAVE, slaveaddr) == -1)
{
close( i2c_fd);
printf( "Unable to setup the i2c port!\n");
return 101;
}
red=read( i2c_fd, buffer, length);
close( i2c_fd);
return 0;
}
//Whats the temperature
void printtemp()
{
char dbuff[2];
//***TEMPERATURE
i2c_read (0x48, dbuff, 1);
printf ("Temperature :- %d degrees C\n", dbuff[0]);
}
int main(void)
{
printtemp();
return 0;
}
