Sending tuples via bluez?
 

hi everybody
lately im working on an exciting project
but i got a problem about about sending two variables at same time via bluez module
therefore,i need to send these two variables as a tuple object , i guess

infact i found a way send two variables at same time as string but it's too laggy and sometimes causing errors
here is my solution which is so laggy:
on client:
def senderfunction():
socket.send(str(a)+' '+str(b))
on server:
a=int(incomingdata[0:3])
b=int(incomingdata[4:len(incomingdata)]

please help

Re: Sending tuples via bluez?
 

variable a and b are numbers between -99 and +99

Re: Sending tuples via bluez?
 

you need no 2*4 bytes to keep 2*1 bytes.
i don't know python, but in C it looks like:
char a, b;
short val = (a << 8) | b;
// send val via socket

--- restore back
short val; // received
char a =( val >>8 ) & 0xFF ,
b = val & 0xFF;

maibe it helps?

Re: Sending tuples via bluez?
 

thanks for reply but i dunno how can apply this to python :/
by the way welcome to our community

Re: Sending tuples via bluez?
 

it works in python for unsigned values:

a = 45
b = 51
val = (a<<8) | b
print val >> 8
print val & 0xFF

--
you my add 99 to both a, b before sending, and minus 99 after:

a = -45 + 99
b = -51 + 99
val = (a<<8) | b
print (val >> 8) - 99
print (val & 0xFF) - 99

to avoid negative values

Re: Sending tuples via bluez?
 

i tried this but it didn't work too
client:
socket.sendall('x'+str(a))
e32.ao_sleep(1)
socket.sendall('y'+str(b))
e32.ao_sleep(1) ##waits for a second

on server:
if incomingdata[0]=='x': a=int(incomingdata[1:len(incomingdata)])
if incomingdata[0]=='y': b=int(incomingdata[1:len(incomingdata)])

Re: Sending tuples via bluez?
 

thanx bro. i got it

Re: Sending tuples via bluez?
 

Consider using struct.pack and struct.unpack for this, it handles packing data into C style structs for you, and deals with endian issues transparently.

Possibly overkill in this case, but if you wanted to send more complex data it is very useful indeed.