def _device_is_water_pump(self):
try:
device_type = None
try:
with Packer() as packer:
# packer.debug = True
# first write => the register address we want read/write
packer.write(self.I2C_REGISTERS["TYPE"])
packer.end()
self._smbus.write_bytes(self._address,
bytearray(packer.read()))
except Exception as e:
print("ERROR: on packer, {}".format(e))
try:
sleep(self._short_timeout)
raw = self._smbus.read_bytes(
self._address,
5) # read 5 bytes from slave due to data format
if self._debug:
print("Raw data from i2c: ", raw)
except Exception as e:
print("ERROR: on smbus, {}".format(e))
try:
with Unpacker() as unpacker:
# unpacker.debug = True
unpacker.write(raw)
device_type = unpacker.read()[
0] # type data is the first field of list
except Exception as e:
print("ERROR: on unpack, {}".format(e))
return device_type == self.I2C_DEVICES_TYPE
except Exception as e:
print("ERROR: on device type check {}".format(e))
def test_packer(self):
packer = Packer()
packer.write(127)
packer.end()
packed = [i for i in packer.read() if i != 0]
expected = [2, 5, 127, 185, 4]
self.assertIsNotNone(packed)
self.assertTrue(type(packed).__name__ == "list")
self.assertEqual(expected, packed)
def read(self, register: int, num_of_bytes: int = 5):
"""
@brief read data from i2c bus
@param register > int i2c register to read
@param num_of_byte > int number of bytes to read started from the register
by default num_of_bytes = 5 because the data format from ESP32 i2c slave is 5 length
more information on Packer() and Unpacker() classes
@return list
"""
# if not self._device_is_water_pump():
# raise Exception("Current device type is not a water pump")
# else:
try:
unpacked = None
try:
with Packer() as packer:
packer.write(register)
packer.end()
packed = packer.read()
if self._debug:
print("packed: ", packed)
self._smbus.write_bytes(self._address, bytearray(packed))
except Exception as e:
print("ERROR: on packer, {}".format(e))
try:
sleep(self._short_timeout) # let the bus process first write
raw = self._smbus.read_bytes(self._address, num_of_bytes)
if self._debug:
print("Raw data from i2c: ", raw)
except Exception as e:
print("ERROR: on smbus, {}".format(e))
try:
with Unpacker() as unpacker:
unpacker.write(list(raw))
unpacked = unpacker.read()
except Exception as e:
print("ERROR: on unpacker, {}".format(e))
if self._debug:
print("Read: %s registers start from: %s" %
(num_of_bytes, hex(register)))
print("Get values: ", unpacked)
return unpacked
except Exception as e:
print("ERROR: on read, {}".format(e))
def write(self, register: int, value=None):
"""
@brief write data through i2c bus
@param register > int/byte i2c register to read
@param value > int/list to be write through i2c
"""
# if not self._device_is_water_pump():
# raise Exception("Current device type is not a water pump")
# else:
try:
with Packer() as packer:
# first write => the register address we want read/write
packer.write(register)
# if value == None we just write register we want read into the i2c bus and then read the value
if None is not value:
if int is not type(value) and list is type(value):
for elm in value:
packer.write(elm)
elif int is type(value):
packer.write(value)
else:
raise Exception("cannot format this kind of data: ",
value)
packer.end() # finish data formatting
packed = packer.read()
except Exception as e:
print("ERROR: {0}, cannot use packer yo prepare data".format(e))
try:
self._smbus.write_bytes(self._address, bytearray(packed))
except Exception as e:
print(
"ERROR: {0}, when write data on i2c: ".format(e),
packed,
)
if self._debug:
print("Write %s on register: %s" % (value, hex(register)))