75   def __init__(self, device=None, serialno=None, wait=1):  argument
84     self._coarse_ref = self._fine_ref = self._coarse_zero = self._fine_zero = 0
85     self._coarse_scale = self._fine_scale = 0
86     self._last_seq = 0
87     self.start_voltage = 0
90       self.ser = serial.Serial(device, timeout=1)
97         self._tempfile = open(tmpname, "w")
103           fcntl.lockf(self._tempfile, fcntl.LOCK_EX | fcntl.LOCK_NB)
109           self.ser = serial.Serial("/dev/%s" % dev, timeout=1)
110           self.StopDataCollection()  # just in case
111           self._FlushInput()  # discard stale input
112           status = self.GetStatus()
123           self.start_voltage = status["voltage1"]
126       self._tempfile = None
132   def GetStatus(self):  argument
153     self._SendStruct("BBB", 0x01, 0x00, 0x00)
155       bytes = self._ReadPacket()
180   def RampVoltage(self, start, end):  argument
184       self.SetVoltage(v)
187     self.SetVoltage(end)
189   def SetVoltage(self, v):  argument
192       self._SendStruct("BBB", 0x01, 0x01, 0x00)
194       self._SendStruct("BBB", 0x01, 0x01, int((v - 2.0) * 100))
197   def SetMaxCurrent(self, i):  argument
202     self._SendStruct("BBB", 0x01, 0x0a, val & 0xff)
203     self._SendStruct("BBB", 0x01, 0x0b, val >> 8)
205   def SetUsbPassthrough(self, val):  argument
207     self._SendStruct("BBB", 0x01, 0x10, val)
210   def StartDataCollection(self):  argument
212     self._SendStruct("BBB", 0x01, 0x1b, 0x01) # Mystery command
213     self._SendStruct("BBBBBBB", 0x02, 0xff, 0xff, 0xff, 0xff, 0x03, 0xe8)
216   def StopDataCollection(self):  argument
218     self._SendStruct("BB", 0x03, 0x00) # stop
221   def CollectData(self):  argument
224       bytes = self._ReadPacket()
235       if self._last_seq and seq & 0xF != (self._last_seq + 1) & 0xF:
237       self._last_seq = seq
240         if not self._coarse_scale or not self._fine_scale:
246             return ((val & ~1) - self._coarse_zero) * self._coarse_scale
248             return (val - self._fine_zero) * self._fine_scale
258         self._fine_zero = data[0][0]
259         self._coarse_zero = data[1][0]
264         self._fine_ref = data[0][0]
265         self._coarse_ref = data[1][0]
273       if self._coarse_ref != self._coarse_zero:
274         self._coarse_scale = 2.88 / (self._coarse_ref - self._coarse_zero)
275       if self._fine_ref != self._fine_zero:
276         self._fine_scale = 0.0332 / (self._fine_ref - self._fine_zero)
279   def _SendStruct(self, fmt, *args):  argument
285     self.ser.write(out)
288   def _ReadPacket(self):  argument
290     len_char = self.ser.read(1)
299     result = self.ser.read(data_len)
308   def _FlushInput(self):  argument
310     self.ser.flush()
313       ready_r, ready_w, ready_x = select.select([self.ser], [], [self.ser], 0)
319         self.ser.read(1)  # This may cause underlying buffering.
320         self.ser.flush()  # Flush the underlying buffer too.