Datasheet

Jon Waddington
62
Figure 4.4.1.4 shows the transmission of the 8 most significant bits of the temperature.
A reset pulse is then sent from the Propeller to inform the DS18B20 that further
information is not required.
The lowest four bits of the temperature can be ignored as they represent the fraction of
centigrades which are not needed in the Information System. Putting the two bytes
together gives a value of 0x1B, or 27°C.
4.4.2 External Temperature
To view an incoming API packet, the Parallax Serial Terminal was used. This allows the
Propeller to communicate with the computer and the software shows the data on the
screen. Figure 4.4.2 shows a screenshot of the software after the Propeller received an
API packet from the XBEE.
Figure 4.4.1.4. Waveform of the 8 least significant bits of the Scratchpad
0
0
0
0
1
0
0
0
LSB MSB
0x01
Figure 4.4.2. Screenshot of the Parallax Serial Terminal displaying an incoming API packet