Sending hex as bytes

Projects Programming
1

hey folks,

i got a series of hex numbers i want to sent as bytes via a BTLE modul set to my arduino.
To debug its connected to my cellphone with a terminal.

What i want my cellphone/later a different receiver, to receive would be this hex line:

fa00, fa0b, 4, fa0b, 2, 0, 1, 0

the way i attempted sending the code from arduino ist this:

SoftwareSerial BTSerial(btTXD, btRXD);
uint8_t firstUin[] = {'fa00', 'fa0b', '4', 'fa0b', '2', '0', '1', '0'};
byte firstByte[] = {'fa','00','fa','0b','04','fa','0b','02','00','01','00'};


Serial.write(firstUin);
BTSerial.write(firstUin);

Serial.write(firstByte);
BTSerial.write(firstByte);

But the cellphone only receives this:

0b4b2010⸮0ab4ab2010a0ab4ab20100b4b2010

a0ab4ab20100b4b2010

What am I doing wonrg?

2 
byte firstByte[] = {0xfa,0x00,0xfa. wtc
3

thanks, having solved one problem makes me find the next one:

Softwareserial BTSerial;

does not accept bytes so how would you encounter transforming it
for the Softwareserial? Without loosing information

4

Softwareserial BTSerial;

does not accept bytes

what does it accept? Bitcoin?

5

who does not accept bitcoin ^^

well its spills this error:

no known conversion for argument 1 from 'byte* {aka unsigned char*}' to 'uint8_t {aka unsigned char}'

so i guess it wants a char.
So the question is how to translate it into a set of chars not loosing the hex informations

6

A simple cast will fix that

7

would you please tell me
wich it would be?

8 
(char*) whateverYourByteBufferNameIs
9

Also you should be aware that a 4 digit hex number won't fit in a byte, so if you tried:

uint8_t firstUin[] = {0xfa00, 0xfa0b, ...

it won't work

10

yes thats why i split them up into these:

byte firstByte[] = {'fa','00','fa','0b','04','fa','0b','02','00','01','00'};
11

But two characters won't fit in a single byte either

12

thanks both of you!

i got another question:
using the "(char*) operation on an array
will only convert the first part of the array?

13

All it does is says to the compiler "look, I'm giving you a pointer to a byte, but I want you to pretend that it's a pointer to a char. Trust me, it'll all work out. Chill"

14

i believe you.
but using it sending an array
it only returns the first set "FA"
the others are gone
but i need to send it as a whole set

15

moe-the-fabber:
yes thats why i split them up into these:

byte firstByte[] = {'fa','00','fa','0b','04','fa','0b','02','00','01','00'};

In that case, what is the purpose of array uint8_t firstUin[]?

16

moe-the-fabber:
i believe you.
but using it sending an array
it only returns the first set "FA"
the others are gone
but i need to send it as a whole set

Are you asking how to do it? You need to post your code, in code tags please.

17

moe-the-fabber:
i believe you.
but using it sending an array
it only returns the first set "FA"
the others are gone
but i need to send it as a whole set

I'd start with defining my "message" correctly... I want to send an array of bytes of the type uint8_t, I'd start with an array of bytes in the type of uint8_t.

uint8_t myMessage[] = {0xFA,0x00,0xFA,0x0B,...
...
...
BTSerial.write(myMessage, sizeof(myMessage));

write()

18

I think the OP wants ASCII encoded hex. But you can sometimes never tell.

19

ok this is where i am at right now:

  byte firstByte[] = {0xfa, 0x00, 0xfa, 0x0b, 0x04, 0xfa, 0x0b, 0x02, 0x00, 0x01, 0x00};

  Serial.write((char*)firstByte,sizeof(firstByte));
  BTSerial.write((char*)firstByte, sizeof(firstByte));

returning only this to my device

FA 00

I am trying out both variable types: byte and uint8_t
but id prefer to use byte

20

Do you see the same result on both serial and BT?