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PIR (PASSIVE INFRARED) DETECTOR USING ST7FLITE05/09/SUPERLITE

1.7.7 Debugging feature

Variable monitoring using RS232 communication

Some parameters can be monitored by connecting the Serial port of a PC to the DB9 con-

nector on board. This is useful in debugging.

The variable to be monitored can be selected in the software using a macro. Please refer to

the software for the meaning of the different variables. By default the ‘Low_var’ variable is

transmitted. Changes in its value can be monitored using the Windows Hyperterminal applica-

tion. Normally the maximum variation in its value should be around 15.

Similarly, other variables (like out_of_threshold, high_v etc) can also be transmitted and can

be displayed using Hyperterminal. These variables change only when a human motion is de-

tected otherwise they remain almost constant.

The implementation of the SCI transmission between the board and the PC is explained in

Section 2.2.

2 SOFTWARE IMPLEMENTATION

These sections describe the algorithms and programming techniques implemented in the var-

ious modules in the software. First, the flowcharts are shown and then each module is ex-

plained.