Sub-routines

AN1353

8/17

Rev 2

4.4

Timing example

Table 5 gives the values which must be loaded into the TSCR register to implement a 1.5 ms

pulse (to trig-ger the light) and a 0.45 ms delayed pulse of 2.8 ms length (to trigger the both

windings of the motor). These are the values programmed by default in the THERM01EVAL

board microcontroller.

5

Sub-routines

5.1

Load control

This sub-routine defines which load has to be turned on (refer to Appendix C). The light bulb

is then controlled de-pending on the door switch information. It is the sensed temperature,

the order set by the external potenti-ometer and the Hysteresis law, described in Figure 3,

that instructs the motor to be ON.

Order 1, the upper limit, equals the temperature order set by an external potentiometer plus

a threshold value (which can be changed, refer to “THRES” in the constants list). Order 2

equals the same order minus this threshold.

Figure 3.

Temperature Hysteresis control

Table 5.

TSCR values to implement the required pulses

NAME

DELAY (ms)

TSCR value (decimal)

T1

0.45 (-code delay)

12 -1

T2

1.05

27

T3

1.75

45

T4

3.95 (-code delay)

101 -3

ORDER 2

ORDER 1

Temperature

MOTOR ON

MOTOR OFF