error in ploting of continuous wave graph form using real time discrete data values

hello experts, i am trying to get real time values from serial port, which is connected to microcontroller... now with the help of MATLAB i am able to get continuous discrete data values in the range 130 to 190.which i have to plot continuous wave form in the range -30 to +30 range ,instead of discrete wave form..... i have posted my code bellow..... help me with the solution or advice please..

before going through the code, data = fscanf(s); returns example ''value1=164v''

close all;

clear all;

clc

s = serial('COM5')

fopen(s);

time=0; delay = 0.005; value=0; delta=0.02; graph1 = plot(time,value, 'g-');

hold on;

while ishandle(graph1)

data = fscanf(s);

 [token, remain] = strtok(data);
 if strcmp(token, 'VALUE1')
     temp1 = strrep(data, 'VALUE1', '');
     temp2 = strrep(temp1, '=', '');
      value = strrep(temp2, 'V', '')

     value = str2double(value);
     value=value-160;

            time=time+delta;
 end 

plot(time,value,'g-','LineWidth',30,'Color',[0 1 0]);

axis([0 time -20 20]);

 drawnow

hold on

    time=time+delta;
     pause(delay);

end