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#include <unistd.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <stdlib.h>
#include "mlan/mlan.h"
//----------------------------------------------------------------------
// Read the temperature of a DS1820
//
// 'SerialNum' - Serial Number of DS1820 to read temperature from
// 'Temp ' - pointer to variable where that temperature will be
// returned
//
// Returns: TRUE(1) temperature has been read and verified
// FALSE(0) could not read the temperature, perhaps device is not
// in contact
//
int ReadTemperature(uchar SerialNum[8], float *Temp)
{
int rt=FALSE;
uchar send_block[30];
int send_cnt=0, tsht, i;
float tmp,cr,cpc;
DOWCRC = 0;
// set the device serial number to the counter device
MLanSerialNum(SerialNum,FALSE);
// access the device
if (MLanAccess())
{
// send the convert temperature command
MLanTouchByte(0x44);
// set the MicroLAN to strong pull-up
if (MLanLevel(MODE_STRONG5) != MODE_STRONG5)
return FALSE;
// sleep for 1 second
msDelay(1000);
// turn off the MicroLAN strong pull-up
if (MLanLevel(MODE_NORMAL) != MODE_NORMAL)
return FALSE;
// access the device
if (MLanAccess())
{
// create a block to send that reads the temperature
// read scratchpad command
send_block[send_cnt++] = 0xBE;
// now add the read bytes for data bytes and crc8
for (i = 0; i < 9; i++)
send_block[send_cnt++] = 0xFF;
// now send the block
if (MLanBlock(FALSE,send_block,send_cnt))
{
// perform the CRC8 on the last 8 bytes of packet
for (i = send_cnt - 9; i < send_cnt; i++)
dowcrc(send_block[i]);
// verify CRC8 is correct
if (DOWCRC == 0x00)
{
// calculate the high-res temperature
tsht = send_block[1];
if (send_block[2] & 0x01)
tsht |= -256;
tmp = (float)(tsht/2);
cr = send_block[7];
cpc = send_block[8];
if (cpc == 0)
return FALSE;
else
tmp = tmp - (float)0.25 + (cpc - cr)/cpc;
*Temp = tmp;
// success
rt = TRUE;
}
}
}
}
// return the result flag rt
return rt;
}
/*
* find next temperature sensor
*/
unsigned char *
nextsensor(void)
{
static unsigned char sn[8];
static int first = 1;
if (first) {
// set the search to first find for temperature family code
MLanFamilySearchSetup(TEMP_FAMILY);
first = 0;
}
for ( ; ; ) {
// perform the search
if (!MLanNext(TRUE, FALSE)) {
return NULL;
}
// get serial number and verify the family code
MLanSerialNum(sn, TRUE);
if (sn[0] == TEMP_FAMILY)
return sn;
}
}
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