Crash_Override/FreeDATA
1
0
Fork 0
mirror of https://github.com/DJ2LS/FreeDATA synced 2024-05-14 08:04:33 +00:00
Code Issues Packages Projects Releases Wiki Activity

append CRC if required by mode

Browse source
This commit is contained in:
DJ2LS 2020-12-22 12:35:49 +01:00 committed by GitHub
parent 9a4517487e
commit b5fc5b6275
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
1 changed files with 21 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

31
test/TEST_TX.py
View file

@ -18,7 +18,7 @@ def main():
modem = FreeDV() #Load FreeDV Class as "modem"
data = b'TEST TEST TEST TEST TEST' #byte string which will be send
data = b'HALLO' #byte string which will be send
modulated_data = modem.Modulate(data) #Call Modulate function, which modulates data and prints it to the terminal
@ -27,12 +27,14 @@ def main():
class FreeDV():
def __init__(self):
self.mode = 12 # define mode
libname = pathlib.Path().absolute() / "libcodec2.so"
self.c_lib = ctypes.CDLL(libname) # Load FreeDV shared libary
self.freedv = self.c_lib.freedv_open(12) #Set FreeDV waveform ( 10,11,12 --> DATA1-3 )
self.freedv = self.c_lib.freedv_open(self.mode) #Set FreeDV waveform ( 10,11,12 --> DATAC1-3 )
self.bytes_per_frame = int(self.c_lib.freedv_get_bits_per_modem_frame(self.freedv)/8) #get bytes per frame from selected waveform
self.payload_per_frame = self.bytes_per_frame -2 #get frame payload because of 2byte CRC16 checksum
self.n_tx_modem_samples = self.c_lib.freedv_get_n_tx_modem_samples(self.freedv)*2 #get n_tx_modem_samples which defines the size of the modulation object
@ -53,14 +55,23 @@ class FreeDV():
data_list = [data_out[i:i+self.payload_per_frame] for i in range(0, len(data_out), self.payload_per_frame)] # split incomming bytes to size of 30bytes, create a list and loop through it
data_list_length = len(data_list)
for i in range(data_list_length): # LOOP THROUGH DATA LIST
#buffer = bytearray(self.bytes_per_frame) # use this if no CRC16 checksum is required
buffer = bytearray(self.payload_per_frame) # use this if CRC16 checksum is required ( DATA1-3)
buffer[:len(data_list[i])] = data_list[i] # set buffersize to length of data which will be send
crc = c_ushort(self.c_lib.freedv_gen_crc16(bytes(buffer), self.payload_per_frame)) # generate CRC16
crc = crc.value.to_bytes(2, byteorder='big') # convert crc to 2 byte hex string
buffer += crc # append crc16 to buffer
if self.mode < 10: # don't generate CRC16 for modes 0 - 9
buffer = bytearray(self.bytes_per_frame) # use this if no CRC16 checksum is required
buffer[:len(data_list[i])] = data_list[i] # set buffersize to length of data which will be send
if self.mode >= 10: #generate CRC16 for modes 10-12..
buffer = bytearray(self.payload_per_frame) # use this if CRC16 checksum is required ( DATA1-3)
buffer[:len(data_list[i])] = data_list[i] # set buffersize to length of data which will be send
crc = c_ushort(self.c_lib.freedv_gen_crc16(bytes(buffer), self.payload_per_frame)) # generate CRC16
crc = crc.value.to_bytes(2, byteorder='big') # convert crc to 2 byte hex string
buffer += crc # append crc16 to buffer
#print(self.bytes_per_frame)
#print(buffer)
data = self.FrameBytes().from_buffer_copy(buffer) #change data format from bytearray to ctypes.u_byte
self.c_lib.freedv_rawdatatx(self.freedv,mod_out,data) # modulate DATA and safe it into mod_out pointer