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   1  #!/usr/bin/env python
   2 ###########################################################################
   3 # obd_sensors.py
   4 #
   5 # Copyright 2004 Donour Sizemore (donour@uchicago.edu)
   6 # Copyright 2009 Secons Ltd. (www.obdtester.com)
   7 #
   8 # This file is part of pyOBD.
   9 #
  10 # pyOBD is free software; you can redistribute it and/or modify
  11 # it under the terms of the GNU General Public License as published by
  12 # the Free Software Foundation; either version 2 of the License, or
  13 # (at your option) any later version.
  14 #
  15 # pyOBD is distributed in the hope that it will be useful,
  16 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 # GNU General Public License for more details.
  19 #
  20 # You should have received a copy of the GNU General Public License
  21 # along with pyOBD; if not, write to the Free Software
  22 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23 ###########################################################################
  24
  25 def hex_to_int(str):
  26     i = eval("0x" + str, {}, {})
  27     return i
  28
  29 def maf(code):
  30     code = hex_to_int(code)
  31     return code * 0.00132276
  32
  33 def throttle_pos(code):
  34     code = hex_to_int(code)
  35     return code * 100.0 / 255.0
  36
  37 def intake_m_pres(code): # in kPa
  38     code = hex_to_int(code)
  39     return code / 0.14504
  40
  41 def rpm(code):
  42     code = hex_to_int(code)
  43     return code / 4
  44
  45 def speed(code):
  46     code = hex_to_int(code)
  47     return code / 1.609
  48
  49 def percent_scale(code):
  50     code = hex_to_int(code)
  51     return code * 100.0 / 255.0
  52
  53 def timing_advance(code):
  54     code = hex_to_int(code)
  55     return (code - 128) / 2.0
  56
  57 def sec_to_min(code):
  58     code = hex_to_int(code)
  59     return code / 60
  60
  61 def temp(code):
  62     code = hex_to_int(code)
  63     return code - 40
  64
  65 def cpass(code):
  66     #fixme
  67     return code
  68
  69 def fuel_trim_percent(code):
  70     code = hex_to_int(code)
  71     return (code - 128.0) * 100.0 / 128
  72
  73 def dtc_decrypt(code):
  74     #first byte is byte after PID and without spaces
  75     num = hex_to_int(code[:2]) #A byte
  76     res = []
  77
  78     if num & 0x80: # is mil light on
  79         mil = 1
  80     else:
  81         mil = 0
  82
  83     # bit 0-6 are the number of dtc's.
  84     num = num & 0x7f
  85
  86     res.append(num)
  87     res.append(mil)
  88
  89     numB = hex_to_int(code[2:4]) #B byte
  90
  91     for i in range(0,3):
  92         res.append(((numB>>i)&0x01)+((numB>>(3+i))&0x02))
  93
  94     numC = hex_to_int(code[4:6]) #C byte
  95     numD = hex_to_int(code[6:8]) #D byte
  96
  97     for i in range(0,7):
  98         res.append(((numC>>i)&0x01)+(((numD>>i)&0x01)<<1))
  99
 100     res.append(((numD>>7)&0x01)) #EGR SystemC7  bit of different
 101
 102     return res
 103
 104 def bin(s):
 105     return str(s) if s<=1 else bin(s>>1) + str(s&1)
 106
 107 def hex_to_bitstring(str):
 108     return bin(int(str, 16))
 109
 110 class Sensor:
 111     def __init__(self,sensorName, sensorcommand, sensorValueFunction, u):
 112         self.name = sensorName
 113         self.cmd  = sensorcommand
 114         self.value= sensorValueFunction
 115         self.unit = u
 116
 117 SENSORS = [
 118     Sensor("          Supported PIDs", "0100", hex_to_bitstring  ,""       ),
 119     Sensor("Status Since DTC Cleared", "0101", dtc_decrypt       ,""       ),
 120     Sensor("DTC Causing Freeze Frame", "0102", cpass             ,""       ),
 121     Sensor("      Fuel System Status", "0103", cpass             ,""       ),
 122     Sensor("   Calculated Load Value", "0104", percent_scale     ,""       ),
 123     Sensor("     Coolant Temperature", "0105", temp              ,"C"      ),
 124     Sensor("    Short Term Fuel Trim", "0106", fuel_trim_percent ,"%"      ),
 125     Sensor("     Long Term Fuel Trim", "0107", fuel_trim_percent ,"%"      ),
 126     Sensor("    Short Term Fuel Trim", "0108", fuel_trim_percent ,"%"      ),
 127     Sensor("     Long Term Fuel Trim", "0109", fuel_trim_percent ,"%"      ),
 128     Sensor("      Fuel Rail Pressure", "010A", cpass             ,""       ),
 129     Sensor("Intake Manifold Pressure", "010B", intake_m_pres     ,"psi"    ),
 130     Sensor("              Engine RPM", "010C", rpm               ,""       ),
 131     Sensor("           Vehicle Speed", "010D", speed             ,"MPH"    ),
 132     Sensor("          Timing Advance", "010E", timing_advance    ,"degrees"),
 133     Sensor("         Intake Air Temp", "010F", temp              ,"C"      ),
 134     Sensor("     Air Flow Rate (MAF)", "0110", maf               ,"lb/min" ),
 135     Sensor("       Throttle Position", "0111", throttle_pos      ,"%"      ),
 136     Sensor("    Secondary Air Status", "0112", cpass             ,""       ),
 137     Sensor("  Location of O2 sensors", "0113", cpass             ,""       ),
 138     Sensor("        O2 Sensor: 1 - 1", "0114", fuel_trim_percent ,"%"      ),
 139     Sensor("        O2 Sensor: 1 - 2", "0115", fuel_trim_percent ,"%"      ),
 140     Sensor("        O2 Sensor: 1 - 3", "0116", fuel_trim_percent ,"%"      ),
 141     Sensor("        O2 Sensor: 1 - 4", "0117", fuel_trim_percent ,"%"      ),
 142     Sensor("        O2 Sensor: 2 - 1", "0118", fuel_trim_percent ,"%"      ),
 143     Sensor("        O2 Sensor: 2 - 2", "0119", fuel_trim_percent ,"%"      ),
 144     Sensor("        O2 Sensor: 2 - 3", "011A", fuel_trim_percent ,"%"      ),
 145     Sensor("        O2 Sensor: 2 - 4", "011B", fuel_trim_percent ,"%"      ),
 146     Sensor("         OBD Designation", "011C", cpass             ,""       ),
 147     Sensor("  Location of O2 sensors", "011D", cpass             ,""       ),
 148     Sensor("        Aux input status", "011E", cpass             ,""       ),
 149     Sensor(" Time Since Engine Start", "011F", sec_to_min        ,"min"    ),
 150     Sensor("  Engine Run with MIL on", "014E", sec_to_min        ,"min"    ),
 151
 152     ]
 153
 154
 155 #___________________________________________________________
 156
 157 def test():
 158     for i in SENSORS:
 159         print i.name, i.value("F")
 160
 161 if __name__ == "__main__":
 162     test()