Recording time series data from Bluetooth by Pybluez

Question

I am currently work in a project that I am using Raspberry-pi to record data from Bluetooth signal. I chosen the PyBluez to program bluetooth. My object is to write the data into csv file, each data point corresponding to the time it was recorded.

I connect the Bluetooth by following code:

port = 1
target_addr = '20:17:08:15:12:41'
sock = bluetooth.BluetoothSocket(bluetooth.RFCOMM)
sock.connect((target_addr, port)

The first way I used to print the signal is sock.recv(1024) and It returned a huge string '-10245\r\n,Red:-10285\r\n,Red:-2918\r\n...' I cannot match each data point into the corresponding time I received it. So I tried the second way which I tried to use readline() function, I convert socket into file and use readline() to read each data value: f = sock.makefile("r+") then f.readline(), the result is not consistence : ed:3124\r\n, Red:-4480\r\n, 1\r\n, :-4480\r\n. Can anyone suggest the way I can read the bluetooth which I can receive a proper string value ex: Red:34612\r\n.

Answer 1

You didn't provide the full program so it is hard to know what you are missing, but I think you probably setting up the client mix up the client/server relationship.

import bluetooth

# setup server
port = 1
target_addr = '20:17:08:15:12:41'
sock=bluetooth.BluetoothSocket( bluetooth.RFCOMM )
sock.bind((target_addr,port))
sock.listen(1)

# setup client
client_sock,address = sock.accept()
print "Accepted connection from ",address

data = client_sock.recv(1024)
print "received [%s]" % data

client_sock.close()
sock.close()

Answer 2

Hi I can read each value from Bluetooth now, I saw the data in consistence so I put a small delay: time.sleep(0.01) then the code f.readline() returned perfect values.