Open Source Car Control ๐Ÿ’ป๐Ÿš—๐Ÿ™Œ
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Open Source Car Control (OSCC) is an assemblage of software and hardware designs that enable computer control of modern cars in order to facilitate the development of autonomous vehicle technology. It is a modular and stable way of using software to interface with a vehicleโ€™s communications network and control systems.

OSCC enables developers to send control commands to the vehicle, read control messages from the vehicleโ€™s OBD-II CAN network, and forward reports for current vehicle control state. Such as steering angle & wheel speeds. Control commands are issued to the vehicle component ECUs via the steering wheel torque sensor, throttle position sensor, and brake position sensor. (Because the gas-powered Kia Soul isnโ€™t brake by-wire capable, an auxiliary actuator is added to enable braking.) This low-level interface means that OSCC offers full-range control of the vehicle without altering the factory safety-case, spoofing CAN messages, or hacking ADAS features.

Although OSCC currently supports only the 2014 or later Kia Soul (petrol and EV), the API and firmware have been designed to make it easy to add new vehicle support. Additionally, the separation between API and firmware means it is easier to modify and test parts of your program without having to update the flashed OSCC modules.

Our Wiki is in the process of being updated to reflect the new changes, but contains a bunch of valuable information to help you get started in understanding the details of the system.


New versions of the API and the firmware are released periodically as new features are added and bugs are fixed. It is of vital importance that you update whenever there is a new version so that you can be certain you are not using a version with known safety issues.

There are four versions to be aware of:

  • Sensor Interface Board (throttle and steering): the version is printed on the front of the shield

  • Vehicle Control Module (EV brakes): the version is printed on the front of the shield

  • Actuator Control Board (petrol brakes): the version is printed on the front of the shield

  • API and Firmware: a single version is shared by both and listed in the Releases section of the repository.

The following table can be used to ensure that you use the appropriate firmware version with your boards:

Board Version Firmware Version
Sensor Interface >= 1.0.0 >= 1.0.0
Vehicle Control 0.1.0 >= 1.1.0
Actuator Control >= 1.2.0 >= 1.0.0
< 1.2.0 * >= 1.0.1

* Later versions of the Actuator Control Board utilize new pins to perform additional safety checks on startup. To use the new firmware on older boards, please see additional instructions in the build section.

Repository Contents

  • api - Software API, so your program can seamlessly talk to our modules.
  • firmware - Arduino libraries and firmware for the OSCC modules.
  • hardware - PCB schematics and board designs for control modules.


The sensor interface and actuator control board schematics and design files are located in the hardware/boards directory. If you don't have the time or fabrication resources, the boards can be purchased as a kit from the OSCC website.

Thanks to Trey German and Macrofab for help designing and manufacturing the custom boards.

Building and Uploading Firmware

The OSCC Project is built around a number of individual firmware modules that inter-operate to allow communication with your vehicle. These modules are built from Arduinos and Arduino shields designed specifically for interfacing with various vehicle components. Once these modules have been installed in the vehicle and flashed with the firmware, the API can be used to receive reports from the car and send spoofed commands.


You must have Arduino Core and CMake (version 2.8 or greater) installed on your machine.

sudo apt install arduino-core build-essential cmake

OSCC uses CMake to avoid some of the limitations of the Arduino IDE. Using this method you can build and upload the firmware from the command-line.

Check out Arduino CMake for more information.

Building the Firmware

Navigate to the firmware directory and create a build directory inside of it:

cd firmware
mkdir build
cd build

To generate Makefiles, tell cmake which vehicle to build for by supplying the appropriate build flag:

Vehicle Flag
Kia Soul Petrol -DKIA_SOUL=ON

For example, if you want to build firmware for the petrol Kia Soul:

cmake .. -DKIA_SOUL=ON

Operator Overrides: While all OSCC modules have operator override detection enabled by default, attempting to grab the steering wheel while the system is active could result in serious injury. The preferred method of operator override for steering is to utilize the brake pedal or E-stop button. To disable operator override for the steering module, pass an additional flag to the CMake build step.


If steering operator overrides remain enabled, the sensitivity can be adjusted by changing the value of the TORQUE_DIFFERENCE_OVERRIDE_THRESHOLD in the corresponding vehicle's header file.

  • Lowering this value will make the steering module more sensitive to operator override, but will result in false positives around high-torque areas, such as the mechanical limits of the steering rack or when quickly and rapidly changing direction.
  • Increasing this value will result in fewer false positives, but will make it more difficult to manually override the wheel.

By default, your firmware will have debug symbols which is good for debugging but increases the size of the firmware significantly. To compile without debug symbols and optimizations enabled, use the following instead:



For older (< 1.2.0) versions of the actuator control board, you need to set an additional flag using cmake .. -DKIA_SOUL=ON -DBRAKE_STARTUP_TEST=OFF to disable startup tests that are not compatible with the previous board design.

This will generate the necessary files for building.

Now you can build all of the firmware with make:


If you'd like to build only a specific module, you can provide a target name to make for whichever module you'd like to build:

make brake
make can-gateway
make steering
make throttle

Uploading the Firmware

Once the firmware is successfully built, you can upload it. When you connect to an Arduino with a USB cable, your machine assigns a serial device to it with the path /dev/ttyACM# where # is a digit starting at 0 and increasing by one with each additional Arduino connected.

You can upload firmware to a single module or to all modules. By default, cmake is configured to expect each module to be /dev/ttyACM0, so if you connect a single module to your machine, you can flash it without changing anything:

make throttle-upload

However, if you want to flash all modules, you need to change the ports in cmake for each module to match what they are on your machine. The easiest way is to connect each module in alphabetical order (brake, CAN gateway, steering, throttle) so that they are assigned /dev/ttyACM0 through /dev/ttyACM3 in a known order. You can then change the ports during the cmake .. step:


Then you can flash all with one command:

make all-upload

Sometimes it takes a little while for the Arduino to initialize once connected, so if there is an error thrown initially, wait a little bit and then retry the command.

Monitoring Arduino Modules

It is sometimes useful to monitor individual Arduino modules to check for proper operation and to debug. If the modules have been built with the flag -DCMAKE_BUILD_TYPE=Debug, their debug printing functionality will be enabled and they will print status information to the serial interface.

The GNU utility screen is one option to communicate with the Arduino via serial over USB. It can be used to both receive the output of any Serial.print statements in your Arduino code, and to push commands over serial to the Arduino. If you don't already have it installed, you can get it with the following command:

sudo apt install screen

You need to enable debug mode with -DDEBUG=ON and tell cmake what serial port the module you want to monitor is connected to (see section on uploading for details on the default ports for each module). The default baud rate is 115200 but you can change it:


You can use a module's monitor target to automatically run screen, or a module's monitor-log target to run screen and output to a file called screenlog.0 in the module's build directory:

make brake-monitor
make brake-monitor-log

You can exit screen with C-a \.

To do more in-depth debugging you can use any of a number of serial monitoring applications. Processing can be used quite effectively to provide output plots of data incoming across a serial connection.

Be aware that using serial printing can affect the timing of the firmware. You may experience strange behavior while printing that does not occur otherwise.

Controlling Your Vehicle - an Example Application

Now that all your Arduino modules are properly setup, it is time to start sending control commands.

We've created an example application, joystick commander, that uses the OSCC API to interface with the firmware, allowing you to send commands using a game controller and receive reports from the on-board OBD-II CAN. These commands are converted into CAN messages, which the OSCC API sends to the respective Arduino modules and are used to actuate the vehicle.

OSCC Joystick Commander

We've also created a ROS node, that uses the OSCC API to interface with the firmware from ROS messages, allowing you to send commands and receive reports in ROS.



Open and close CAN channel to OSCC Control CAN.

oscc_result_t oscc_open( uint channel );
oscc_result_t oscc_close( uint channel );

These methods are the start and end points of using the OSCC API in your application. oscc_open will open a socket connection on the specified CAN channel, enabling it to quickly receive reports from and send commands to the firmware modules. When you are ready to terminate your application, oscc_close can terminate the connection.


The OSCC API catches the SIGIO signal which is asserted when a CAN frame is received on the CAN socket, and sets up a SIGIO signal handler to forward valid CAN messages to your application. If you have a section of code that is susceptible to conflicts with interrupts, you should temporarily block the SIGIO signal for the duration of that section and unblock it afterward.

Enable and disable all OSCC modules.

oscc_result_t oscc_enable( void );
oscc_result_t oscc_disable( void );

After you have initialized your CAN connection to the firmware modules, these methods can be used to enable or disable the system. This allows your application to choose when to enable sending commands to the firmware. Although you can only send commands when the system is enabled, you can receive reports at any time.

Publish control command to the corresponding module.

oscc_result_t publish_brake_position( double normalized_position );
oscc_result_t publish_steering_torque( double normalized_torque );
oscc_result_t publish_throttle_position( double normalized_position );

These commands will forward a double value to the specified firmware module. The double values are [0.0, 1.0] for brake and throttle, and [-1.0, 1.0] for steering where -1.0 is counterclockwise and 1.0 is clockwise. The API will construct the appropriate values to send as spoofed voltages to the vehicle to achieve the desired state. The API also contains safety checks to ensure no voltages outside of the vehicle's expected range are sent.


Each of these functions must be called at least once every 200ms to prevent the modules from detecting a loss of communication to the controlling computer (at which point they would disable themselves).

Register callback function to handle OSCC report and OBD messages.

oscc_result_t subscribe_to_brake_reports( void(*callback)(oscc_brake_report_s *report) );
oscc_result_t subscribe_to_steering_reports( void(*callback)(oscc_steering_report_s *report) );
oscc_result_t subscribe_to_throttle_reports( void(*callback)(oscc_throttle_report_s *report) );
oscc_result_t subscribe_to_fault_reports( void(*callback)(oscc_fault_report_s *report) );
oscc_result_t subscribe_to_obd_messages( void(*callback)(struct can_frame *frame) );

In order to receive reports from the modules, your application will need to register a callback handler with the OSCC API. When the appropriate report for your callback function is received from the API's socket connection, it will then forward the report to your software.

Each module's reports are described in their respective wiki sections:

In addition to OSCC specific reports, it will also forward any non-OSCC reports to any callback function registered with subscribe_to_obd_messages. This can be used to view CAN frames received from the vehicle's OBD-II CAN channel. If you know the corresponding CAN frame's id, you can parse reports sent from the car.


There are two types of tests available: unit and property-based.

Test Dependencies

The unit tests and property-based tests each have their own set of dependencies required to run the tests.

For the unit tests you must have Cucumber 2.0.0 and its dependency Boost installed:

sudo apt install ruby-dev libboost-dev
sudo gem install cucumber -v 2.0.0

For the property-based tests you must have Rust, its build manager Cargo, and libclang:

sudo apt install rustc cargo clang libclang-dev

Running Tests

Building and running the tests is similar to the firmware itself, but you must instead tell cmake to build the tests instead of the firmware with the -DTESTS=ON flag. We also pass the -DCMAKE_BUILD_TYPE=Release flag so that cmake will disable debug symbols and enable optimizations, good things to do when running tests to ensure nothing breaks with optimizations. Lastly, you must tell the tests which vehicle header to use for the tests (e.g., -DKIA_SOUL=ON).

cd firmware
mkdir build
cd build

Unit Tests

Each module has a suite of unit tests that use Cucumber with Cgreen. There are pre-built 64-bit Linux versions in firmware/common/testing/framework.

Boost is required for Cucumber-CPP and has been statically linked into libcucumber-cpp.a. If you need to build your own versions you can use the provided script which will install the Boost dependencies (needed for building), clone the needed repositories with specific hashes, build the Cgreen and Cucumber-CPP libraries, and place static Boost in the Cucumber-CPP library.

The built libraries will be placed in an oscc_test_framework directory in the directory that you ran the script from. You can then copy oscc_test_framework/cucumber-cpp and oscc_test_framework/cgreen to firmware/common/testing/framework.

We can run all of the unit tests available:

make run-unit-tests

Each module's test can also be run individually:

make run-brake-unit-tests
make run-can-gateway-unit-tests
make run-steering-unit-tests
make run-throttle-unit-tests

If everything works correctly you should see something like this:

# language: en
Feature: Receiving commands

  Commands received from a controller should be processed and acted upon.

  Scenario Outline: Enable throttle command sent from controller        # firmware/throttle/tests/features/receiving_commands.feature:8
    Given throttle control is disabled                                  # firmware/throttle/tests/features/receiving_commands.feature:9
    And the accelerator position sensors have a reading of <sensor_val> # firmware/throttle/tests/features/receiving_commands.feature:10
    When an enable throttle command is received                         # firmware/throttle/tests/features/receiving_commands.feature:12
    Then control should be enabled                                      # firmware/throttle/tests/features/receiving_commands.feature:14
    And the last command timestamp should be set                        # firmware/throttle/tests/features/receiving_commands.feature:15
    And <dac_a_val> should be written to DAC A                          # firmware/throttle/tests/features/receiving_commands.feature:16
    And <dac_b_val> should be written to DAC B                          # firmware/throttle/tests/features/receiving_commands.feature:17

      | sensor_val | dac_a_val | dac_b_val |
      | 0          | 0         | 0         |
      | 256        | 1024      | 1024      |
      | 512        | 2048      | 2048      |
      | 1024       | 4096      | 4096      |

Property-Based Tests

The throttle, steering, and brake modules, along with the PID controller library, also contain a series of property-based tests.

We can run all of the property-based tests available:

make run-property-tests

Each module's test can also be run individually:

make run-brake-property-tests
make run-steering-property-tests
make run-throttle-property-tests
make run-pid-library-property-tests

Once the tests have completed, the output should look similar to the following:

running 7 tests
test check_integral_term ... ok
test check_derivative_term ... ok
test check_proportional_term ... ok
test check_reversed_inputs ... ok
test check_same_control_for_same_inputs ... ok
test check_zeroize ... ok

test result: ok. 7 passed; 0 failed; 0 ignored; 0 measured

   Doc-tests tests

running 0 tests

test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured

All Tests

Finally, as a convenience you can run all available tests:

make run-all-tests

Additional Vehicles & Contributing

OSCC currently has information regarding the Kia Soul PS (2014-2018), but we want to grow! The repository is structured to facilitate including more vehicles as more is learned about them.

In order to include information related to a new vehicle's specification, follow the format defined in api/include/vehicles/kia_soul.h and add a cmake option to choose your new header when compiling the API.

Please see

License Information

Hardware source materials (e.g. schematics, board layouts, wiring diagrams, data sheets, physical installation documentation, 3D models, etc.) for the OSCC (Open Source Car Control) Project are licensed under Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0).

Firmware and software source for the OSCC (Open Source Car Control) Project is licensed under the MIT License (MIT) unless otherwise noted (e.g. 3rd party dependencies, etc.).

Please see for more details.

Contact Information

Please direct questions regarding OSCC and/or licensing to

Distributed as-is; no warranty is given.

Copyright (c) 2017 PolySync Technologies, Inc. All Rights Reserved.