Projects of the ‘Phone/Sound’ Category

Office Phone Station statistics processing

2011/05, customer: “Gradsoft”, outsourcing, 1 developer
result: charts are built
dev. OS: Windows XP; languages: Java SE 6; tools: Eclipse, Redmine, MS Excel

Building Excel charts on calls statistic to see maximum lines load and its duration during every day. The aim was to minimize number of external phone lines (analyzing daily peak load).

@ Software, Algorithms and Data Processing, Phone/Sound

“Abetka” – Talking Ukrainian letters

2010, private project 1 developer
result: implemented for my daughter
OS: Windows XP; tools: MS Power Point

MS Power Point presentation with table of Ukrainian letters which produce one’s sound on click.

Download Abetka PP Presentation with player. Extract files from archive and run play.bat. Click on letters.

Downloads, Home/Entertainment, Other, Phone/Sound

2-8 channels phone line PC adapter

2004, customer: private project, 1 developer
result: 8 and 2 channels versions were implemented
OS: Windows XP; tools: Orcad, oscilloscope & solder iron

2 channels per board adapters of phone line. Decoupled output to Sound Blaster input of PC, line on-hook sensing of each line via Joystick port. Amplifiers with auto gain control.
It was made to be used with ready software for calls registration Atropos-SB (

Design, Electronics, PCB Design, Phone/Sound

8-channels phone calls digitizer system with DOS storage software

2001, customer: private project, 1 developer
result: sold and used
OS: DOS; MC: AT89C52; languages: C; tools: TC 2.0, PN, i51 ะก cross-compiler

External MC based adapter detects on-hook line state, digitizes phone line signals and sends mixed stream of all active channels to PC via LPT port.
DOS software splits the stream and stores phone call data to separate WAV files for each active channel.
Access to stored data was made over network.

@ Software, Data Acquisition and Control, Microcontrollers, Phone/Sound

TTS digital board for phone number tones detection

1990-1991 (9 months being student), customer: Zhitomir Trunk Telephone Station, outsourcing, 1 developer
result: 1 sample was implemented and tested, they had started serial manufacturing
OS/Hardware: DOS/designed MC board; languages: Assembler i8051; tools: i8051 cross assembler

This board (for Computer controlled TTS) substitutes analog one. It detects tones of coded phone number that is passed between TTS of cities.
Prior to digital board TTS had larger percentage of errors while number detection.
Board includes i8031 MC (i51 w/o internal ROM), RAM/ROM, phone line interface with analog filter of input signal, TTS rack interface (6 logical outputs for each tone in code) and switching power unit (TTS 24V to board’s power).

Microcontrollers, Phone/Sound, Power Units, Signal Processing

Doorbell with 30 melodies

1990, aim: the gift for friend, 1 developer
result: was granted and was used during several years
hardware: soldered controller board; languages: Assembler i8080; tools: developed at i8080 based computer

MC board and FW were developed: i8080, 2kB ROM, NO RAM (only registers of CPU), 30 cyclic 1 tone melodies.

Home/Entertainment, Microcontrollers, Phone/Sound

AON – digital detector of caller phone number

1989, customer: private firm, 1 developer
result: 1 sample supplied and used
hardware: soldered controller board; languages: Assembler i8080; tools: developed at i8080 based computer

It was my first designed MC board: i8080, 2kB ROM, NO RAM (only registers of CPU), 8 digits 7-segment LED indicator, phone line interface, NO ADC (analog signal was sampled as bit stream).
Written FW: digital 6 tones caller number decoding and indicating.

Microcontrollers, Phone/Sound, Signal Processing