Franck1991
Newbie level 2
Hello everyone! My name is Franck. I am final year student. I am doing my project now but it is not working. My problem is with the DTMF decoder circuit. I am using the MT8870 DTMF decoder IC, the MT8870 DTMF decoder circuit is given in its datasheet and it is not giving me any ouput. I am pretty sure my problem lies at the input. The input is from the mobile phone, pressing the keypad of the phone generates DTMF tones. so i need to connect the phone to the DTMF decoder. I have used hands-free, open ear-bud and solder two wires to the two wires connected to the speaker inside the ear-bud. then i connected one wire to ground and the other to pin 2. i m still getting nothing. please can someone help me troubleshooting my MT8870 DTMF decoder circuit? I seriously need help.