def test_crc_single_bit_changed():
data_a = [0x3f,0x1a,0xff,0x56,0x3a]
crc_a = crc16(data_a)
data_b = [0x3f,0x1a,0xef,0x56,0x3a]
crc_b = crc16(data_b)
assert crc_a != crc_b
def test_returned_value_float():
distantio = distantio_protocol()
# inputs
var_id = 124
fmt = 0
value = 1.362e-12
extraid_1 = 1.25
extraid_2 = 12715
# formatting
v = (var_id).to_bytes(2,byteorder='big')
n = pack(distantio.format_lookup[fmt],value)
frame = bytearray()
frame.append(0x01)
frame += v
frame.append(fmt)
frame += pack('>f',extraid_1)
frame += pack('>H',extraid_2)
frame += n
crc = crc16(frame).to_bytes(2,byteorder='big')
frame += crc
response = distantio.process(frame)
assert response['type'] == 'returned-value'
assert response['var-id'] == var_id
assert round(response['var-value'],5) == round(value,5)
assert response['var-type'] == fmt
assert round(response['var-time'],5) == round(extraid_1,5)
assert response['var-array-index'] == extraid_2
def test_returned_value_writeable_int():
distantio = distantio_protocol()
# inputs
var_id = 124
fmt = 0xF3
value = 126594521
extraid_1 = 2.725
extraid_2 = 9513
# formatting
v = (var_id).to_bytes(2,byteorder='big')
n = pack(distantio.format_lookup[fmt & 0x0F],value)
frame = bytearray()
frame.append(0x01)
frame += v
frame.append(fmt)
frame += pack('>f',extraid_1)
frame += pack('>H',extraid_2)
frame += n
crc = crc16(frame).to_bytes(2,byteorder='big')
frame += crc
response = distantio.process(frame)
assert response['type'] == 'returned-value'
assert response['var-id'] == var_id
assert response['var-value'] == value
assert response['var-type'] == fmt & 0x0F
assert round(response['var-time'],5) == round(extraid_1,5)
assert response['var-array-index'] == extraid_2
def test_returned_descriptor_variable_writeable():
distantio = distantio_protocol()
# inputs
var_id = 999
name = "testvariable 2"
fmt = 0xF3
# formatting
formatted_name = "{:14s}".format(name)
v = (var_id).to_bytes(2,byteorder='big')
n = bytes(formatted_name,'ascii')
frame = bytearray()
frame.append(0x00)
frame += v
frame.append(fmt)
frame += n
crc = crc16(frame).to_bytes(2,byteorder='big')
frame += crc
response = distantio.process(frame)
assert response['type'] == 'returned-descriptor'
assert response['var-id'] == var_id
assert response['var-name'] == formatted_name
assert response['var-type'] == fmt & 0x0F
assert response['var-writeable'] == True
def test_decode_group_descriptor():
distantio = distantio_protocol()
# inputs
group_id = 39
fmt = 0x07
name = "testvar"
# formatting
formatted_name = "{:14s}".format(name)
n = bytes(formatted_name,'ascii')
# formatting
v = (group_id << 10).to_bytes(2,byteorder='big')
frame = bytearray()
frame.append(0x00)
frame += v
frame.append(fmt)
frame += n
crc = crc16(frame).to_bytes(2,byteorder='big')
frame += crc
response = distantio.process(frame)
assert response['type'] == 'returned-group-descriptor'
assert response['group-id'] == group_id
assert response['group-name'] == formatted_name
def test_returned_descriptor_variable_non_writeable():
distantio = distantio_protocol()
# inputs
var_id = 999
group_id = 18
name = "testvariable 1"
fmt = 3
# formatting
formatted_name = "{:14s}".format(name)
data_ID = (var_id + (group_id << 10)).to_bytes(2,byteorder='big')
data = bytes(formatted_name,'ascii')
frame = bytearray()
frame.append(0x00)
frame += data_ID
frame.append(fmt)
frame += data
crc = crc16(frame).to_bytes(2,byteorder='big')
frame += crc
# Testing frame
response = distantio.process(frame)
assert response['type'] == 'returned-descriptor'
assert response['var-id'] == var_id
assert response['var-name'] == formatted_name
assert response['var-type'] == fmt
assert response['var-writeable'] == False
assert response['var-group'] == group_id
def get_descriptors_frame(self):
packet = bytearray(self.frame_size)
# Build data frame
packet[self.cmd_start] = 0x02
# Compute and pack CRC
packet[self.crc_start:self.crc_end] = crc16(packet[:-2]).to_bytes(2,byteorder='big')
return packet
def get_stop_reading_frame(self,variable_id,variable_type):
packet = bytearray(self.frame_size)
packet[self.cmd_start] = 0x06
packet[self.data_id_start:self.data_id_end] = variable_id.to_bytes(2,byteorder='big')
packet[self.data_type_start] = variable_type
packet[self.crc_start:self.crc_end] = crc16(packet[:-2]).to_bytes(2,byteorder='big')
return packet
def test_alive_signal():
distantio = distantio_protocol()
frame = bytearray(18)
frame[0] = 0x03
crc = crc16(frame).to_bytes(2,byteorder='big')
frame += crc
response = distantio.process(frame)
assert response['type'] == 'alive-signal'
def get_write_value_frame(self,variable_id,variable_type,value):
packet = bytearray(self.frame_size)
# Cast value to chosen type
if variable_type == 0:
value = float(value)
else:
value = int(value)
packet[self.cmd_start] = 0x04
packet[self.data_id_start:self.data_id_end] = variable_id.to_bytes(2,byteorder='big')
packet[self.data_type_start] = variable_type
packet[self.data_start:self.data_end] = pack(self.format_lookup[variable_type],value)
packet[self.crc_start:self.crc_end] = crc16(packet[:-2]).to_bytes(2,byteorder='big')
return packet
def test_decode_wrong_cmd():
distantio = distantio_protocol()
var_id = 38153
name = "testvariable 1"
formatted_name = "{:14s}".format(name)
v = (var_id).to_bytes(2, byteorder='big')
n = bytes(formatted_name, 'ascii')
frame = bytearray()
frame.append(0xFF) # Wrong command
frame += v
frame.append(0x00)
frame += n
crc = crc16(frame).to_bytes(2, byteorder='big')
frame += crc
assert pytest.raises(ValueError, distantio.process, frame)
def test_returned_descriptor_wrong_format():
distantio = distantio_protocol()
var_id = 38153
name = "testvar"
formatted_name = "{:14s}".format(name)
v = (var_id).to_bytes(2, byteorder='big')
n = bytes(formatted_name, 'ascii')
frame = bytearray()
frame.append(0x00)
frame += v
frame.append(0xFF) # Wrong format
frame += n
crc = crc16(frame).to_bytes(2, byteorder='big')
frame += crc
assert pytest.raises(ValueError, distantio.process, frame)
def test_decode_wrong_cmd():
distantio = distantio_protocol()
var_id = 38153
name = "testvariable 1"
formatted_name = "{:14s}".format(name)
v = (var_id).to_bytes(2,byteorder='big')
n = bytes(formatted_name,'ascii')
frame = bytearray()
frame.append(0xFF)# Wrong command
frame += v
frame.append(0x00)
frame += n
crc = crc16(frame).to_bytes(2,byteorder='big')
frame += crc
assert pytest.raises(ValueError,distantio.process,frame)
def test_returned_descriptor_wrong_format():
distantio = distantio_protocol()
var_id = 38153
name = "testvar"
formatted_name = "{:14s}".format(name)
v = (var_id).to_bytes(2,byteorder='big')
n = bytes(formatted_name,'ascii')
frame = bytearray()
frame.append(0x00)
frame += v
frame.append(0xFF)# Wrong format
frame += n
crc = crc16(frame).to_bytes(2,byteorder='big')
frame += crc
assert pytest.raises(ValueError,distantio.process,frame)
def test_crc_know_value():
# test the alive-signal from DistantIO
data = [0x03,0x00,0x00,0x00,0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17]
crc = crc16(data)
assert crc == 13216
def process(self,frame):
returned_instruction = dict()
returned_instruction['type'] = None
# First, check data size
if len(frame) != self.frame_size:
raise IndexError("Frame size "+str(len(frame))+", expecting "+str(self.frame_size))
# Second, check crc
crc_frame = unpack('>H',frame[-2:])[0]
crc_ref = crc16(frame[:-2])
if crc_frame != crc_ref:
raise ValueError("CRCs do not match, crc frame : "+str(crc_frame)+" versus reference :"+str(crc_ref))
# Identify command
cmd = frame[self.cmd_start]
# returned-descriptor command
if cmd == 0x00:
# Check format is valid
raw_format = frame[self.data_type_start] & 0x0F
if raw_format < 0 or raw_format > 7:
raise ValueError("Received format identifier "+str(raw_format)+" unknown.")
# Received a group descriptor
if raw_format == 7:
returned_instruction['type'] = 'returned-group-descriptor'
value = unpack('>H',(frame[self.data_id_start:self.data_id_end]))[0]
value = (value >> 10) & 0x3F
returned_instruction['group-id'] = value
returned_instruction['group-name'] = frame[self.var_name_start:self.var_name_end].decode(encoding='UTF-8')
else:
returned_instruction['type'] = 'returned-descriptor'
var_id = unpack('>H',(frame[self.data_id_start:self.data_id_end]))[0]
var_id = var_id & 0x3FF
var_group = unpack('>H',(frame[self.data_id_start:self.data_id_end]))[0]
var_group = (var_group >> 10) & 0x3F
returned_instruction['var-id'] = var_id
returned_instruction['var-type'] = raw_format
returned_instruction['var-writeable'] = ((frame[self.data_type_start])>>4 & 0x0F == 0x0F)
returned_instruction['var-name'] = frame[self.var_name_start:self.var_name_end].decode(encoding='UTF-8')
returned_instruction['var-group'] = var_group
return returned_instruction
# returned-value command
if cmd == 0x01:
returned_instruction['type'] = 'returned-value'
# Check format is valid
raw_format = frame[self.data_type_start] & 0x0F
if raw_format < 0 or raw_format > 6:# TODO : Change with format lookup
raise ValueError("Received format identifier "+str(frame)+" unknown.")
value = unpack('>H',(frame[self.data_id_start:self.data_id_end]))[0]
value = value & 0x3FF
returned_instruction['var-id'] = value
returned_instruction['var-type'] = raw_format
returned_instruction['var-value'] = unpack(self.format_lookup[raw_format],frame[self.data_start:self.data_end])[0]
returned_instruction['var-time'] = unpack('>f',frame[self.extraid_1_start:self.extraid_1_end])[0]
returned_instruction['var-array-index'] = unpack('>H',frame[self.extraid_2_start:self.extraid_2_end])[0]
return returned_instruction
# alive-signal command
if cmd == 0x03:
returned_instruction['type'] = 'alive-signal'
return returned_instruction
# Emergency send
if cmd == 0x09:
returned_instruction['type'] = 'emergency-send'
returned_instruction['data-id'] = frame[self.data_id_start:self.data_id_end].decode(encoding='UTF-8')
# Check format is valid
raw_format = frame[self.data_type_start] & 0x0F
if raw_format < 0 or raw_format > 6:# TODO : Change with format lookup
raise ValueError("Received format identifier "+str(frame)+" unknown.")
returned_instruction['data-type'] = raw_format
returned_instruction['data-time'] = unpack('>f',frame[self.extraid_1_start:self.extraid_1_end])[0]
returned_instruction['data-index'] = unpack('>H',frame[self.extraid_2_start:self.extraid_2_end])[0]
returned_instruction['data-value'] = unpack(self.format_lookup[raw_format],frame[self.data_start:self.data_end])[0]
return returned_instruction
raise ValueError("Received command "+str(cmd)+" unknown.")
