Dilshan R Jayakody’s Web Log

CLI, also known as Caller ID and calling number delivery ( CND ), is a service offered by the telephone service provider to customers to obtain the calling party number and date/time of the call. The service activation and information format of CLI are different from telephone network operator to operator. CLI display unit - minimum test setup In this project, we will create a small Caller ID decoder using Arduino UNO and a custom-made HT9032D module. The core component of the project is the HT9032D, which can decode incoming call ID data over a telephone connection. This IC supports Bell 202 FSK and ITU-T version 2.3 CLI protocol specifications. The HT9032D module we created here base on the application example given in the IC datasheet . In addition to decoding CLI data, this module also can detect ring signal rises over the phone line. Assembled HT9032D module The Arduino UNO is used to process the decoded CLI data stream and manipulate the LCD. In an idle state, the decoder a...

This project is about 4046 PLL base simple FSK modem. Under given configuration this modem send digital signals over two frequencies and which is switching around 378kHz and 226kHz. In this system, modulator uses VCO of 4046, and demodulator is based on close loop mode of 4046 phase comparator and external LPF assembly. This FSK modem is specifically design to transfer digital signals over mixed signal lines and it can directly use with any slow digital interfaces like UARTs. This system operates reliably under 10kHz range and we test it with standard TTL inputs. 1kHz Input signal and demodulated signal 1kHz Input signal and modulated signal The given PCB of this system is based on SMD components but it can also construct using standard through-hole components. During our prototyping we test this system with ATmega series microcontrollers and TTL signals sources. Because of 4046 CMOS implementation this unit can operate in between 3V to 12V by without using any extern...