//------------------------------------------------------------------------------
// Read temperatures and humidity. Pass a NULL pointer if you are not interested
// in the repective measurement value.
int mbug_2820_read( mbug_device dev, double *temperature, double *humidity )
{
char data[16] = {0};
int ret = 0;
char* endp = 0;
if (temperature != 0) *temperature = -300;
if (humidity != 0) *humidity = -300;
// Read 1st data packet
ret = mbug_write( dev, "\xA0\x00\x01", 3);
if (ret<0) return -1;
ret = mbug_read( dev, data, 8 );
if (ret<0) return -1;
// Read 2nd data packet
ret = mbug_write( dev, "\xA0\x01\x01", 3);
if (ret<0) return -1;
ret = mbug_read( dev, data+8, 8 );
if (ret<0) return -1;
// Convert temperature
ret = 0;
data[7] = '\0';
if (temperature != 0) {
errno = 0;
*temperature = strtod(data, &endp);
if (errno || *endp != '\0') {
*temperature = -300;
return -1;
}
}
// Convert humidty
data[15] = '\0';
if (humidity != 0) {
errno = 0;
*humidity = strtod(data+8, &endp);
if (errno || *endp != '\0') {
*humidity = -300;
return -1;
}
}
// Test for device errors. Specific error code is located at data[5:6] as hex ascii.
if (*temperature <= NOT_A_TEMPERATURE && data[4]=='\0' && data[5]!='\0') {
*humidity = *temperature = -300 - strtol(data+5, 0, 16); // until an extended error handler is written: just add
ret = -1;
}
return ret;
}
//------------------------------------------------------------------------------
// Read all temperatures (ascii mode)
int mbug_2818_read_all( mbug_device dev, double temperatures[], int n )
{
char data[64] = {0};
int i, ret;
if (n>8) n=8;
for (i=0; i<n; i++)
temperatures[i] = NOT_A_TEMPERATURE;
ret = mbug_write( dev, "\xFB\xA0", 2);
if (ret<2) return -1;
ret = mbug_read( dev, data, 64 );
if (ret<64) return -1;
data[63] = '\0';
for (i=0; i<n; i++)
{
char* a = data + i*8;
if ( !strncmp(a+1, "inf", 3) ) // thermometer returns "+inf" or "-inf" on overflow
continue;
temperatures[i] = atof(a);
}
return 0;
}
//------------------------------------------------------------------------------
// Read the current temperature (ascii mode)
double mbug_2810_read_ascii( mbug_device dev )
{
char tem[16] = {0};
if (mbug_write( dev, "read", 5) <5)
return NOT_A_TEMPERATURE;
if (mbug_read( dev, tem, 8 ) <8)
return NOT_A_TEMPERATURE;
return atof(tem);
}
//------------------------------------------------------------------------------
// Read raw sensor value
int mbug_2810_read_raw( mbug_device dev )
{
unsigned char in[16] = {0};
if (mbug_write( dev, "\xFA\xA0\xF2", 3) <3) // Raw format (0xF2 is the old revisions read cmd)
return NOT_A_TEMPERATURE;
if (mbug_read( dev, in, 8 ) <8)
return NOT_A_TEMPERATURE;
return in[0]+(in[1]<<8);
}
//------------------------------------------------------------------------------
// Read the current temperature (ascii mode)
double mbug_2810_read_ascii( mbug_device dev )
{
char str[16] = {0};
double tem;
if (mbug_write( dev, "read", 5) <5)
return NOT_A_TEMPERATURE;
if (mbug_read( dev, str, 8 ) <8)
return NOT_A_TEMPERATURE;
tem = atof(str);
if (tem < NOT_A_TEMPERATURE)
tem -= strtol(str+5, 0, 16);
return tem;
}
//------------------------------------------------------------------------------
// Read raw data
long mbug_2820_read_raw( mbug_device dev )
{
char data[8] = {0};
int ret;
ret = mbug_write( dev, "\xA0\x00\x00", 3);
if (ret<0) return -1;
ret = mbug_read( dev, data, 8 );
if (ret<0) return -1;
return *(long*)data;
}
//------------------------------------------------------------------------------
// Private helper function:
// Generic I/O command: Send cmd, receive integer parameter
// Return values <0 indicate errors.
static int io( mbug_device dev, unsigned char* out, size_t size )
{
unsigned char in[8] = {0};
short status = 0;
int value = 0;
if (mbug_write( dev, out, size ) <0)
return -1;
if (mbug_read( dev, in, sizeof(in) ) <0)
return -1;
// First 2 bytes contain the return status (signed 16 bit)
status = *(short*) in;
// Next 4 bytes contain the returned output value
value = *(int*) (in+2);
if (status<0) return status;
else return value;
}
//------------------------------------------------------------------------------
// Read raw data
int mbug_2818_read_raw( mbug_device dev, unsigned short data[], int n )
{
char data_in[64] = {0};
int i, ret;
if (n>8) n=8;
for (i=0; i<n; i++)
data[i] = 0;
ret = mbug_write( dev, "\xFA\xA0", 2);
if (ret<2) return -1;
ret = mbug_read( dev, data_in, 64 );
if (ret<64) return -1;
// Only the first 16 bytes carry values
for (i=0; i<n; i++)
{
data[i] = data_in[i*2]+data_in[i*2+1]*256;
}
return 0;
}
