Working of caller id project Items tagged with Working of caller id project

First of all talking about the circuit. I will give a brief description of the ICs used.
1. MT8870: A DTMF decoder IC, parallel o/p.
2. AT89C2051: 8051 Controller
3. LCD: For display
4. MCT 2E: Opto coupler to check the receiver is picked or not.

Now Software..
The code is really simple, at the top is ports definition. Defining the MT8870 interface as..

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