RS232 Phone Dialer

This is a RS232 phone dialer. Which means you can dial & control a telephone call via the PC software.

Operation

The whole concept based on pulse dialing which in many modems used. The circuit has two output relays.

Relay2 = pulse dialing
Relay1 = control output (connects an external record playback unit)

Software

Software consists of two parts. Dialing and the Sound Source.

Dialing

If you enter a telephone number in the “Telephone Number” text box & press dial it will automatically dial the corresponding number. After dialing completed it will automatically turn on the “Sound Output”

Sound source

*External record unit – can connect an external record/ playback unit.
*Sound card – can use mp3 music from your pc without taking any external playback units.

If you have selected “External record unit" then after dialing completed it will turn on “Sound Output” & relay1.when you press “sound output” it will toggle the relay1 which helps to turn on or off the external record units sound.

If you have selected “Sound card” you can select an mp3 from your PC & playback to the phone. After dialing completed it will turn on “sound output” & plays the selected song. When you press “sound output” it will pause the playback & when you again press it will play the music back.

Note: If you selected “Sound card” then the relay1 will be permanently turned on. It won’t toggle the relay1 like in the “External record unit” mode.

If you want to answer the phone just press & turn off the “Sound Output” & answer the phone. If you need again to play the audio track just press the “Sound Output” again.

If you need to cancel a call press the “cancel” button at any time & it will ready to accept a new telephone number to dial.

Schematic