Contents
Introduction
4
1.
Project Overview ~ Integrated Telephone Data logging (ITDL) System
5
2.
Telephone Interface and Number Encoding
7
3.
Polarity reversal and interrupt handling
8
4.
Real Time Clock and Time Management
9
5.
Information Storage
10
6.
Printer interfacing
11
7.
Interfacing to computer
12
8.
Power Supply and Battery Backup
13
9.
ITDL Front panel connectors, Accessories and Physical dimensions
14
10.
Software Design
15
11.
Result
20
12. Problems encounted 20
13.
Conclusions
21
14.
Complete circuit diagram of ITDL
22
15.
Complete PCB layout f ITDL
23
Reference
24
Appendix
25