OBD-KKL-KW1281-ARDUINO-TRIPCOMPUTER

Напрямую arduino соединить с кан-шиной нельзя. Нужен конвертер уровней. Для этих целей подходит L9637D. Он подключается по классической схеме:

Данная схема встречается с дополнительной микросхемой ELM327. На моем ситрояне используется протокол ISO 14230. По тому достаточно только L9637D.

Схема питается от 12-и вольт в obd разьеме через линейный стабилизатор на 5 вольт.

K-line — пин 7 колодки, L-line пин 15 . земля пины 4 и 5, плюс пин 16. Общая распиновка разьема obd такая:

Соединяем Tx микросхемы L9637D с 14-ым пином Ardiono, uart пины с usb-ttl адаптером.

Загружаем скетч, запускаем и.. Я получил вот такой первый пакет:

C1 33 F1 81 66 83 F1 10 C1 E9 8F BD C2 33 F1 01 0C F3 84 F1 10 41 0C 0D 20 FF C2 33 F1 01 05 EC 83 F1 10 41 05 49 13 C2 33 F1 01 0F F6 83 F1 10 41 0F 47 1B

где
C1 33 F1 81 66 — эхо на запрос инициализации шины
83 F1 10 C1 E9 8F BD — ответ ЭБУ на запрос инициализации, C1 значит ОК
C2 33 F1 01 0C F3 — эхо на запрос оборотов двигателя
84 F1 10 41 0C 0D 20 FF — ответ ЭБУ с оборотами, где 0D 20 (HEX) >> 3360 (DEC)/4 = 840 об/мин
C2 33 F1 01 05 EC — эхо на запрос температуры ОЖ двигателя
83 F1 10 41 05 49 13 — ответ ЭБУ с температурой, где 49 (HEX) >> 73 (DEC) -40 = 33 град.
C2 33 F1 01 0F F6 — эхо на запрос температуры всасываемого воздуха
83 F1 10 41 0F 47 1B — ответ ЭБУ с температурой, где 47 (HEX) >> 71 (DEC) -40 = 31 град.

Далее немного доработал код и сделал вывод данных на oled дисплей.

Содержание

Arduino Uno Display Tripcomputer for the KW1281 KKL K-Line protocol
Welcome
Features
Setup Instructions
KWP1281 Communication
Label Files
Credit
Caution
Use this at your own risk. Be cautious. Damaging your car or your cars ECU is possible. Wrong wiring and setup can create a fire hazard. In rare cases the airbags can deploy when reading DTC errors on 0x15. The OBD was meant to be a diagnostics port only, by using a tripcomputer through it the workload on the ECU increases.
Problems
Future

Arduino Uno Display Tripcomputer for the KW1281 KKL K-Line protocol

Welcome

Simple trip computer for the Arduino Uno with a 16×2 Screen to display useful information in all VAG vehicles with the MARELLI 4LV ECU (VAG Number: 036906034AM). This includes most Golf mk4/Jetta/Bora from the years around 2000 that are limited to the K-Line communication and the KW1281 protocol. Newer cars since around 2005 began to adapt OBD-2 with CAN communication, that can be accessed through a ELM327 controller. No such simple controller exists currently for KKL.

This repo contains all necessary files. The only file containing code is obdisplay.cpp.

Features

Supported baud rates 1200, 2400, 4800, 9600, 10400
Supports KWP1281 K-Line through NewSoftwareSerial
3 operating modes: Acknowledge, Group reading, Sensors reading
Read, view and delete DTC Errors
Supported ECU addr 0x01(engine) and 0x17(dashboard)
Automatic communication error handling
Simulation mode to test the display
KWP1281 exit procedure

Setup Instructions

Requirements: Arduino Uno, 16×2 Liquidcrystal Display Shield, Autodia K409 KKL OBD to USB cable

Look inside the OBD cable and note which MCU is placed (E.g. FT232R or FT232RQ), get its datasheet, find the RXD and TXD pins, solder the first visible contact point to your Arduino digital pins of your liking (Here: 2 and 3) and cut both lines after the contact point. Don’t forget to solder the +5V and GROUND from your Arduino to the OBD cable MCU (Just use the USB stripped male on the platine) since without it no communication is possible. You should have 4 cables connected between your OBD cable and your Arduino and a seperate USB or power souce input to power the Arduino and access its Serial debug communication.

See the pictures below for visual guidance.

Refer to the linked git repo for pictures and a bit more info.

KWP1281 Communication

KWP_INIT

KWP_LOOP

After initialization you can select 3 KWP_MODES:

0 = Keep connection alive, send acknowledge blocks
1 = Read all values from all groups from ECU. (ECU dependent, you may need to adapt to yours)
2 = Read the 4 values from one group. (ECU independent, see group menu)

Communication errors can occur which are handled by the code. There may be situations where this is not the case, please open an issue if this happens to you.

Label Files

The measurement groups of each ECU Addres contain 4 values. Each different version of each car may have a different order of values and different values to obtain. To know which groups display which values you either need to search for your cars Label File “xxx-xxx-xxx.LBL” or hook up VCDS (or any other software to display measurement groups) and record your display while clicking through the groups to get a rough image what these values correspond to.

Here are the values for the 036906034AM MARELLI ECU for the 1.6 16V Engine, which partly does not contain label files:

<div dir="auto" data-snippet-clipboard-copy-content="const uint8_t ADDR_ENGINE = 0x01;
// Label File: None
// Measurement Blocks – 0x08:
// Group 00: 1-10 with 3 digit numbers
// Group 01: 0 /min RPM, 17.0°C Temperature, 0.0% Lambda, 10110010 Binary Bits **
// Group 02: 0 /min RPM, 0.0% Load, 0.0ms Time Correction, 1012.0 mbar Absolute Pressure
// Group 03: 0 /min RPM, 1012.0 mbar Absolute Pressure, 5.4° T.B. Angle, 0.0° Steering Angle **
// Group 04: 0 /min RPM, 11.70 V Voltage, 17.0°C Temperature, 14°C Temperature **
// Group 05: 0 /min RPM, 0.0% Load, 0.0 km/h Speed, Part Throttle NA
// Group 06: 0 /min RPM, 0.0% Load, 14°C Temperature, -1.0% Lambda **
// Group 14: 0 /min RPM, 0.0% Load, 0.0 no units, Enabled NA
// Readiness – 0x15:
// Readiness Status: 10100101
// Exhaust Gas Recirculation: Failed or Incomplete
// Oxygen Sensor Heating: Passed
// Oxygen Sensor(s): Failed or Incomplete
// Air Conditioning: Passed
// Secondary Air Injection: Passed
// Evaporative Emissions: Failed or Incomplete
// Catalyst Heating: Passed
// Catalytic Converter(s): Failed or Incomplete
const uint8_t ADDR_ABS_BRAKES = 0x03; // UNUSED
// Label File: None
// Measurement Blocks – 0x08:
// Group 4: 0.00° Steering Angle, 0.31 m/s^2 Lateral Acceleration, -0.36°/s Turn Rate, N/A
// Group 5: -1.27 bar Pressure, 0.42 bar Pressure, N/A, N/A
const uint8_t ADDR_AUTO_HVAC = 0x08; // UNUSED
// Label File: 381-907-044.LBL
// Measurement Blocks – 0x08:
// Group 1: 8.0 A/C clutch sw-off cond. 1-12, 0.0 Eng. speed recog (0=no, 1=yes), 0.0 km/h Road Speed, 121.0 Standing time (0-240min.)
// Group 2: 42.0 Measured Value, 42.0 Specified Value, 219.0 Position: air supply cooled, 42.0 Position: air supply heated
// Group 3: 221.0 Measured Value, 221.0 Specified Value, 221.0 Position: air flow to panel, 40.0 Position: air flow to footwell
// Group 4: 223.0 Measured Value, 223.0 Specified Value, 223.0 Position: air flow to footwell, 39.0 Position: air flow to defroster
// Group 5: 237.0 Measured Value, 234.0 Specified Value, 234.0 Position: fresh air, 30.0 Position: recirculating
// Group 6: 0.0°C Temp displayed on panel, 7.0°C Temp. air intake duct, 0.0°C Outside air temperature, 0.0% Sun photo sensor (0-120%)
// Group 7: 0.0 Outlet temp. panel (G191), 5.0°C Outlet temp. floor (G192), 3.0°C Panel temp. near LCD (G56), 0.0 n/a
// Group 8: 0.00V Specif. Voltage air blower, 0.28V Measured Voltage air blower, 12.18V Measured Voltage A/C clutch, 0.0 no units
const uint8_t ADDR_INSTRUMENTS = 0x17;
// Label File: 1J0-920-xx0.LBL
// Measurement Blocks – 0x08:
// Group 1: 0.0 km/h Speed, 0 /min Engine Speed, Oil Pr. 2

 ADDR_ENGINE = ; Label File: None Group 00: 1-10 with 3 digit numbers Group 01: 0 /min RPM, 17.0°C Temperature, 0.0% Lambda, 10110010 Binary Bits ** Group 02: 0 /min RPM, 0.0% Load, 0.0ms Time Correction, 1012.0 mbar Absolute Pressure Group 03: 0 /min RPM, 1012.0 mbar Absolute Pressure, 5.4° T.B. Angle, 0.0° Steering Angle ** Group 04: 0 /min RPM, 11.70 V Voltage, 17.0°C Temperature, 14°C Temperature ** Group 05: 0 /min RPM, 0.0% Load, 0.0 km/h Speed, Part Throttle NA Group 06: 0 /min RPM, 0.0% Load, 14°C Temperature, -1.0% Lambda ** Group 14: 0 /min RPM, 0.0% Load, 0.0 no units, Enabled NA Readiness - 0x15: Readiness Status: 10100101 Exhaust Gas Recirculation: Failed or Incomplete Oxygen Sensor Heating: Passed Oxygen Sensor(s): Failed or Incomplete Air Conditioning: Passed Secondary Air Injection: Passed Evaporative Emissions: Failed or Incomplete Catalyst Heating: Passed Catalytic Converter(s): Failed or Incomplete ADDR_ABS_BRAKES = ;  Label File: None Group 4: 0.00° Steering Angle, 0.31 m/s^2 Lateral Acceleration, -0.36°/s Turn Rate, N/A Group 5: -1.27 bar Pressure, 0.42 bar Pressure, N/A, N/A ADDR_AUTO_HVAC = ;  Label File: 381-907-044.LBL Group 1: 8.0 A/C clutch sw-off cond. 1-12, 0.0 Eng. speed recog (0=no, 1=yes), 0.0 km/h Road Speed, 121.0 Standing time (0-240min.) Group 2: 42.0 Measured Value, 42.0 Specified Value, 219.0 Position: air supply cooled, 42.0 Position: air supply heated Group 3: 221.0 Measured Value, 221.0 Specified Value, 221.0 Position: air flow to panel, 40.0 Position: air flow to footwell Group 4: 223.0 Measured Value, 223.0 Specified Value, 223.0 Position: air flow to footwell, 39.0 Position: air flow to defroster Group 5: 237.0 Measured Value, 234.0 Specified Value, 234.0 Position: fresh air, 30.0 Position: recirculating Group 6: 0.0°C Temp displayed on panel, 7.0°C Temp. air intake duct, 0.0°C Outside air temperature, 0.0% Sun photo sensor (0-120%) Group 7: 0.0 Outlet temp. panel (G191), 5.0°C Outlet temp. floor (G192), 3.0°C Panel temp. near LCD (G56), 0.0 n/a Group 8: 0.00V Specif. Voltage air blower, 0.28V Measured Voltage air blower, 12.18V Measured Voltage A/C clutch, 0.0 no units ADDR_INSTRUMENTS = ; Label File: 1J0-920-xx0.LBL Group 1: 0.0 km/h Speed, 0 /min Engine Speed, Oil Pr. 2 < min (Oil pressure 0.9 bar), 21:50 Time Group 2: 121960 Odometer, 9.0 l Fuel level, 93 ohms Fuel Sender Resistance, 0.0°C Ambient Temperature Group 3: 12.0°C Coolant temp., OK Oil Level (OK/n.OK), 11.0°C Oil temp, N/A

Credit

Thanks to many wonderful projects for making this project less painful than it already is.

Blafusel with a detailed overview on the KW1281 protocol and the communication between the microcontroller and the ECU.

mkirbst’s existing code helped a lot to get the mainframe going. His code did not work on my car, although he has a very similar one to mine using the same protocol. He refers to some connection problems, which I also got that can only be caused by the software. This project eliminates connection problems by implementing a procedure for error messages by the ECU.

Caution

Use this at your own risk. Be cautious. Damaging your car or your cars ECU is possible. Wrong wiring and setup can create a fire hazard. In rare cases the airbags can deploy when reading DTC errors on 0x15. The OBD was meant to be a diagnostics port only, by using a tripcomputer through it the workload on the ECU increases.

This is an early version and I’m only releasing it to help on anyones journey with this VAG mess. You need to manually remove connections and solder cables on an OBD to USB board and hook them up to the Arduino Uno TX and RX pins. You need to turn ignition ON for the ECU to start. This software should not break anything in the ECU, since only the measure groups are accessed. Depending on your car, you may need to adapt this code for various values.

Be careful when working with the Airbag Address 0x15 since in some rare circumstances when an electrical failure is given in the airbag system and DTC error codes are deleted the airbag can deploy on affected ECU’s. I would hardly advise not to touch the Airbag controller with selfmade code.

This project may work with other Arduino’s, Displays, OBD cables and VAG cars.

Problems

If you have questions feel free to open an issue and paste your Serial log there.