DTMF Dialer with Holtek HT9200A (Serial Mode) v1.0
Compiler         : MikroC Pro for PIC 6.0.1
MCU                 : PIC45K22  @ 32MHz (8MHz x 4xPLL)
                           Can be any other MCU (ROM>1570bytes RAM>147bytes)

Pins Description : PortC (RC1) to HT9200A CE   Pin 1 (Chip On is low, Chip Off is high)
                               PortC (RC4) to HT9200A DATA Pin 6 (D0,D1,D2,D3 bits)
                               PortC (RC3) to HT9200A CLK  Pin 5 (Data synchronous clock)
                                                         HT9200A DTMF Pin 7 (DTMF Signal Output 0,45V-0,75V)
Description        : HT9200A uses a 5-bit code, and a synchronous clock to generate a DTMF signal.
                               Each DTMF digit is made by serie of 5 bits. D0 is LSB (first received bit).
                               HT9200A will latch data on the falling edge of the clock (CLK pin).  

DTMF HT9200A example without library: \DTMF HT9200A Example\

DTMF HT9200A Library with simple example: \DTMF HT9200A Library\

Holtek HT9200A IC coding explanation: \HT9200A Tutorial\

Code example with library usage:

#include "DTMF_HT9200A.h"

void main()
{
   DTMF("1234567890");       // <<-- Generate DTMF for 1234567890
}