DTMF Signal Lookup Table (LUT) in MATLAB: Mapping Characters to Frequencies

This code defines the input characters and their corresponding DTMF signals as arrays, then creates a containers.Map object to store the one-to-one correspondence between them. The containers.Map object allows us to easily look up the DTMF signal for a given input character. We can test the LUT by using the disp function to output the DTMF signal for a few example input characters.

% Define the input characters and their corresponding DTMF signals
inputChars = {'1','2','3','A','4','5','6','B','7','8','9','C','#','0','*','D'};
DTMFSignals = [
    697 1209; 697 1336; 697 1477; 697 1633;
    770 1209; 770 1336; 770 1477; 770 1633;
    852 1209; 852 1336; 852 1477; 852 1633;
    941 1209; 941 1336; 941 1477; 941 1633;
];

% Create the LUT using a container.Map object
DTMFMap = containers.Map(inputChars, DTMFSignals);

% Test the LUT by looking up a few input characters
disp(DTMFMap('1')); % should output [697 1209]
disp(DTMFMap('5')); % should output [770 1336]
disp(DTMFMap('#')); % should output [941 1477]

This code provides a simple yet effective solution for mapping characters to DTMF signals. You can easily adapt this code to create similar LUTs for various applications requiring signal mapping.