External power mode of evaluation board
UM0452
8/30
3
External power mode of evaluation board
This mode is also called standalone mode of the evaluation board. In this mode the board is
supplied by an external power supply and continuously displays the time and temperature
on LCD. We do not need any computer interface for this mode.
3.1
Powering of evaluation board
To power up the board, follow these steps:
1.
Select the power selection switch (S1) to external power mode as explained above.
2.
Plug in the DC power supply through adapter (7.5 V - 19 V output). As soon as power is
plugged in, the green LED (EXT) lights up.
Note:
This LED (EXT) shows only that power is connected or not. Power to board is selected
through the power selection switch (S1).
3.2
Address selection on the evaluation board
There are a total of 6 address switches on the board: three for temperature sensor 1 (TS1)
and the other three for temperature sensor 2 (TS2).
Switches A0, A1, A2 are used for configuring the address lines of the temperature sensor 1
and A0#, A1#, A2# are used for configuring the address lines of temperature sensor 2.
Logic level is assigned to the address line using the address selection switches.
shows the position of the switch and the respective logic level assigned by that switch.
Note:
Address 0x9E is used for selecting the temperature sensor package on the board.
If TS1 = 0x9E then TS2 is selected for temperature measurement and if TS2 = 0x9E then
TS1 is selected for the temperature measurement.
Figure 5.
Logical level and relative switch positions