Transmitting buffer over Serial missing dropping bytes?

Using Arduino Networking, Protocols, and Devices
#1

Hi Arduino fans,

I have this weird thing going with my program. Basically I am transmitting a char buffer over Serial (bluetooth) but some parts get lost somewhere.

Example:

Serial bluetooth;

char buff[5];

buff[0] = 15;
buff[1] = 0;
buff[2] = 0;
buff[3] = 3;
buff[4] = 0;

bluetooth.write(buff);
bluetooth.write(13); <--- new line character

What happens is that I do receive the 15, but the rest is gone until the 13 (new line character)
However, if the buffer contains:

buff[0] = 15;
buff[1] = 1;
buff[2] = 1;
buff[3] = 3;
buff[4] = 0;

Then its ok.

My Android app logic is:

byte b = inputstream.read();

if(b==13) // the delimeter{
 process the whole buffer;
}else{
add b to buffer;
}

What am I missing?

Thanks guys.

#2

bluetooth.write( buff, sizeof(buff) );

#3

I am using SoftwareSerial for the bluetooth but it seems that it does not like it:

v2.cpp: In function 'void sendBluetooth(message_t)':
v2:180: error: invalid conversion from 'char*' to 'const uint8_t*'
v2:180: error: initializing argument 1 of 'virtual size_t Print::write(const uint8_t*, size_t)'

Should I need some different serial library?

#4

Should I need some different serial library?

No. The function expects one type of data. You have another. Lie to it; tell it you have what it expects:

bluetooth.write( (const uint8_t*)buff, sizeof(buff) );

#5

Or change the data-type of buff…

uint8_t buff[5];

#6 
bluetooth.write(13); <--- new line character

13 is carriage-return.

If you want a newline:

bluetooth.write('\n');

If you really want a carriage-return:

bluetooth.write('\r');
#7

Thank you gentlemen, I have sorted it out by changing the buff type to uint8_t.

Thanks again. :slight_smile:

#8