how to send 100 digit in serial communication from processing to arduino - arduino

Question

i am converting pixel array to String and send this String to arduino. but i Think this String is not converted properly because Serial.write send (8 bit or 8 character) i don’t know. and also want to send 100 character of string into Serial .
please send your suggestion and getting help me out of this problem.
for any mistake Sorry in advance.
for(int x =0 ; x < img.height; x++)
{
for(int y=0; y <img.width; y++)
{
int i = x+y*width;
if(img.pixels[i] == color(0,0,0))
{
i=1;
}
else
{
i=0;
}
String s = str(i);
print(s);
Serial.write(s);
delay(2);
}
}
and also tell me how to stop string after 100 character by not using ("\n" or "\r" )

Answer 1

It seems you are looking for the code below:
for (int x = 0; x < img.height; x++) { // iterate over height
for (int y = 0; y < img.width; y++) { // iterate over width
int i = x + y * width;
if (img.pixels[i] == color(0, 0, 0)) { // determine if zero
Serial.write('1'); // send non zero char
} else {
Serial.write('0'); // send zero char
}
}
Serial.write("\n\r");
}
If you want to cluster your output in units the size of img.width you could do this:
for (int x = 0; x < img.height; x++) { // iterate over height
String s;
for (int y = 0; y < img.width; y++) { // iterate over width
int i = x + y * width;
if (img.pixels[i] == color(0, 0, 0)) { // determine if zero
s += '1'; // append a non zero char to string s
} else {
s += '0'; // append a zero char to string s
}
}
Serial.println(s);
}
Please remember:
Serial.write outputs raw binary value(s).
Serial.print outputs character(s).
Serial.println outputs character(s) and appends a newline character to output.
I have serious doubts about this calculation int i = x+y*width; as your data is probably structured as:
vertical data: 0 1 2
horizontal data: [row 0][row 1][row 2]
Instead of:
horizontal data: 0 1 2
vertical data: [column 0][column 1][column 2]