Of course the values are not the same! C is a char but E is a double. Also, you say you reshaped C but you didn't do it in the code you show. That C and E could be equal (if they were the made to be the same size and data type) should not be too hard to prove to yourself, simply make a test...
For example, run this in a function M-file. Notice the ISEQUAL call at the end. If C and E are equal, it will say 1, if they are not, it will say 0. See for yourself!
looptimes = 1;
F = ceil(rand(1,5000000)*90); % Random data...
send_count = 1;
Idk = (1+5000*(send_count-1)):(5000*send_count);
%
%
% Make C.
%
%
C = zeros(16,(5000*looptimes));
for ii=1:length(Idk)
C(:,ii) = F((-15+16*(Idk(ii))):16*(Idk(ii)));
end
C = char(reshape(C,1,16*5000));
%
%
% Now make E.
%
%
E = [];
for ii=1+5000*(send_count-1):5000*send_count
E = [E F((-15+16*(ii)):16*(ii))];
end
isequal(C,char(E))
