How to control sampling rate of MCP3008 that interface with Arduino Mega 2560 Board

[jayfoonglw]

Hello, my problem is how to control the sampling rate of MCP3008 such as 100 samples per seconds, 1000 samples per seconds in the Matlab Coding since the maximum sampling rate of MCP3008 is 200ksps (based on datasheet of MCP3008)?This is because I noticed that this coding only produce 1 sample per second (for 8 channels) when write the data (ADC value) into a excel file.

Thanks you very much and very appreciate for helping. Hereby, I attached the previous Matlab codes used for performs ADC operation by using MCP3008 in Arduino Mega 2560 Board as shown in below.

%a=arduino('COM27')  %create the object tha represents our arduino & we establish the serial port when is connected in my case is com 27
clear ('tt','count','time','r','t','voltage','adcvalue','adcvalue1','voltage','channel1','channel2','channel3','channel4','channel5','channel6','channel7', 'channel8','v','tic','toc');

i = 1;
j = 1;
n = 0;
r = 1;
y = 0;
counter = 1;

in=0;%in pin
tic;%start a time count
time(150)=0;%pre allocate memory to speed up execution of code
v(150)=0;
ib=0;

fid = fopen('C:\Users\Foong Lik Wei\Desktop\try2.csv', 'w+') ;
fclose(fid);

fid = fopen('C:\Users\Foong Lik Wei\Desktop\try2.csv', 'a') ;
  
   fprintf(fid, '\n') ;
   fprintf(fid, '\n') ;
   fprintf(fid, ',Timestamp') ; % Print the time string
   fprintf(fid, ',Elapsed Time (s)') ; % Print the time string
   fprintf(fid, ',Channel 1') ; % Print the time string
   fprintf(fid, ',Channel 2') ; % Print the time string
   fprintf(fid, ',Channel 3') ; % Print the time string
   fprintf(fid, ',Channel 4') ; % Print the time stringfprintf(fid, ',Channel 1') ; % Print the time string
   fprintf(fid, ',Channel 5') ; % Print the time string
   fprintf(fid, ',Channel 6') ; % Print the time string
   fprintf(fid, ',Channel 7') ; % Print the time string
   fprintf(fid, ',Channel 8') ; % Print the time string
fclose(fid) ;


SELPIN= 53;
DATAOUT = 51;
DATAIN = 50;
SPICLOCK = 52;

a.pinMode(SELPIN, 'OUTPUT');
a.pinMode(DATAOUT, 'OUTPUT');
a.pinMode(DATAIN, 'INPUT');
a.pinMode(SPICLOCK, 'OUTPUT');

a.digitalWrite(SELPIN,1);   % '1' means HIGH
a.digitalWrite(DATAOUT,0);  % '0' means LOW 
a.digitalWrite(SPICLOCK,0);


while toc<20   
for op = 1: 1 : 8
adcvalue = 0;

a.digitalWrite(SELPIN,0);


  if  op == 1
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
 
  
     elseif op == 2
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
  
  
     elseif op == 3
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
  
      
     elseif op == 4
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
      
  
     elseif op == 5
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
      
      
     elseif op == 6
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
 
     elseif op == 7
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,0);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
   
      
     elseif op == 8
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
    
     a.digitalWrite(DATAOUT,1);
     a.digitalWrite(SPICLOCK,1);
     a.digitalWrite(SPICLOCK,0);
      
  end


a.digitalWrite(SPICLOCK, 1);
a.digitalWrite(SPICLOCK, 0);
a.digitalWrite(SPICLOCK, 1);
a.digitalWrite(SPICLOCK, 0);
for kk = 9: -1: 0
  dd = a.digitalRead(DATAIN);
  uu = bitshift (dd, kk);
  adcvalue = adcvalue + uu;
 
  a.digitalWrite(SPICLOCK, 1);
  a.digitalWrite(SPICLOCK, 0);
end   
   
a.digitalWrite(SELPIN, 1);

adcvalue1(op) = adcvalue;

end   

adcvalue1;
channel1(counter) = (adcvalue1(1) /1023)*5;
channel2(counter) = (adcvalue1(2) /1023)*5;
channel3(counter) = (adcvalue1(3) /1023)*5;
channel4(counter) = (adcvalue1(4) /1023)*5;
channel5(counter) = (adcvalue1(5) /1023)*5;
channel6(counter) = (adcvalue1(6) /1023)*5;
channel7(counter) = (adcvalue1(7) /1023)*5;
channel8(counter) = (adcvalue1(8) /1023)*5;
  hello1 = transpose(channel1);
 
  hello2 = transpose(channel2);
  hello3 = transpose(channel3);
  hello4 = transpose(channel4);
  hello5 = transpose(channel5);
  hello6 = transpose(channel6);
  hello7 = transpose(channel7);
  hello8 = transpose(channel8);
   
  counter = counter + 1; 
   
  n = n +1; 
          
   
    ib=ib+1;
    time(ib)=toc;%creates a vector containing the diferents moments given by "toc"
    v1(ib)=hello1(r);%vector that stores the sampled values ??of voltage
    v2(ib)=hello2(r);
    v3(ib)=hello3(r);
    v4(ib)=hello4(r);
    v5(ib)=hello5(r);
    v6(ib)=hello6(r);
    v7(ib)=hello7(r);
    v8(ib)=hello8(r);
      
  timestamp = datenum(now);
  c = datevec ( timestamp );
  s{r} = datestr ( c, 'yyyy-mm-dd-HH:MM:SS' );
  s2 = transpose(s);
  s2 ;

time(j) = toc;
j = j + 1;
realtime = transpose(time);
realtime;

fid = fopen('C:\Users\Foong Lik Wei\Desktop\try2.csv', 'a') ;

fprintf(fid, '\n');  % Print the data values
   fprintf(fid, ',');  % Print the data values
   fprintf(fid, '%s', s2{r}) ; % Print the time string
   fprintf(fid, ',%12.3f', realtime(r));
   fprintf(fid, ',%12.3f', v1(r));  % Print the data values
   fprintf(fid, ',%12.3f', v2(r));
   fprintf(fid, ',%12.3f', v3(r));
   fprintf(fid, ',%12.3f', v4(r));
   fprintf(fid, ',%12.3f', v5(r));
   fprintf(fid, ',%12.3f', v6(r));
   fprintf(fid, ',%12.3f', v7(r));
   fprintf(fid, ',%12.3f', v8(r));
  
fclose(fid) ;

r = r + 1;  
  
end