First pass at driver, and doc

ilt1000.py

@@ -0,0 +1,97 @@
+#!/usr/bin/python3
+
+import datetime
+import serial
+
+
+class Error(Exception):
+  pass
+
+
+class UnsupportedCommand(Error):
+  pass
+
+
+class RequiredValueNotSet(Error):
+  pass
+
+
+class OutOfRange(Error):
+  pass
+
+
+class Saturated(Error):
+  pass
+
+
+class ILT1000(object):
+
+  def __init__(self, device, set_time=True):
+    self._dev = serial.Serial(device, 115200)
+    try:
+      # clear junk in outgoing buffer
+      self._SendCommand('echooff')
+    except UnsupportedCommand:
+      pass
+    assert int(self._SendCommand('echooff')) == 0
+    if set_time:
+      self.SetDateTime()
+
+  def _SendCommand(self, command):
+    self._dev.write(command.encode('ascii') + b'\r\n')
+    ret = self._dev.readline().rstrip().decode('ascii')
+    if ret == '-999':
+      raise UnsupportedCommand(command)
+    if ret == '-500':
+      raise RequiredValueNotSet(command)
+    if ret == '-501':
+      raise OutOfRange(command)
+    if ret == '-502':
+      raise Saturated(command)
+    return ret
+
+  def GetModelName(self):
+    return self._SendCommand('getmodelname')
+
+  def GetGeneration(self):
+    return int(self._SendCommand('getgeneration'))
+
+  def GetFirmwareVersion(self):
+    return self._SendCommand('getfwversion')
+
+  def GetSerialNumber(self):
+    return self._SendCommand('getserialnumber')
+
+  def GetControllerTempF(self):
+    return int(self._SendCommand('gettemp'))
+
+  def GetAmbientTempF(self):
+    # Protocol doc indicates that this is degrees F * 100, but actual values
+    # look like just degrees F
+    return int(self._SendCommand('getambienttemp'))
+
+  def GetDateTime(self):
+    ret = self._SendCommand('getdatetime')
+    return datetime.datetime.fromtimestamp(int(ret.split()[2]))
+
+  def SetDateTime(self, now=None):
+    now = now or datetime.datetime.utcnow()
+    timestr = now.strftime('%m/%d/%Y %H:%M:%S')
+    ret = self._SendCommand('setdatetime ' + timestr)
+    assert int(ret) == 0
+
+  def GetCurrentPicoAmps(self):
+    ret = self._SendCommand('getcurrent')
+    return float(ret)
+
+  def GetVoltage(self):
+    ret = self._SendCommand('getvoltage')
+    return float(ret) / 1000000
+
+  def GetTransmissionPercent(self):
+    ret = self._SendCommand('gettrans')
+    return float(ret) / 10
+
+  def GetOpticalDensity(self):
+    ret = self._SendCommand('getod')
+    return float(ret) / 100