The modern car is a rolling computer, constantly monitoring a wealth of data about its operation. For car enthusiasts and those interested in vehicle diagnostics, accessing this data can be incredibly valuable. While OBD2 ports are primarily used for diagnostics and communicating with your car’s computer, many are now exploring ways to display this real-time data on more accessible screens, such as those using HDMI. This article delves into the possibilities of connecting Obd2 To Hdmi, drawing upon insights from experts in the field of automotive CAN bus communication.
Understanding OBD2 and CAN Bus
Before exploring the connection to HDMI, it’s crucial to understand the basics. OBD2 (On-Board Diagnostics II) is a standardized system that allows you to access vehicle data. This data is transmitted via the CAN bus (Controller Area Network), a communication network that allows different modules within your car to talk to each other.
Think of the CAN bus as the nervous system of your car, and OBD2 as a standardized access point to get information from this system. This information includes a wide range of parameters, known as PIDs (Parameter IDs), such as engine temperature, speed, RPM, and much more.
[Quote from: ecoboostsho on February 28, 2019, 10:41:43 AM in forum post]
The modules communicate directly between them via addresses on the CANBUS so you need to be able to intercept that communication or have it originate on the scan tool.
This quote highlights the fundamental challenge: accessing and interpreting CAN bus communication. Modules within your car communicate using specific addresses and protocols. To display this data, you need a way to “intercept” this communication and make sense of it.
The Role of Scan Tools and Adapters
Traditionally, scan tools are used to interface with the OBD2 port. These tools, like FORSCAN mentioned in the original forum post, can request and display PIDs. To move beyond dedicated scan tools and display data on HDMI screens, specialized adapters and interfaces are needed.
[Quote from: ecoboostsho on February 28, 2019, 10:41:43 AM in forum post]
With a scan tool (like FORSCAN for instance) you could sniff the traffic between the PC and the car to see what the responses were. If you are actually trying to intercept a communication between modules (like what the Explorer does when you put it in SAND mode as the example you sent me via PM) you have to have a way to see that PID response and that won’t be easy.
This implies that understanding the communication protocols and PID responses is key to accessing and displaying the desired data. “Sniffing” the traffic, as mentioned, refers to capturing and analyzing the data being transmitted on the CAN bus.
Connecting OBD2 Data to HDMI: Possible Approaches
Directly connecting an OBD2 port to an HDMI display is not possible. HDMI is a video output standard, while OBD2 is a data communication port. Therefore, an intermediary device is required to bridge this gap. This device must:
- Read OBD2 data: Connect to the OBD2 port and access CAN bus information.
- Process data: Interpret the raw CAN bus data and extract relevant PIDs.
- Convert to HDMI output: Format and output the processed data as a video signal compatible with HDMI displays.
Several solutions exist or are being developed to achieve this:
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Dedicated OBD2 to HDMI Adapters: Some commercial products are designed specifically to read OBD2 data and display it on an HDMI screen. These often come pre-configured to show common vehicle parameters in a user-friendly dashboard format. These adapters handle the data processing and HDMI conversion internally.
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DIY Solutions with Microcontrollers: For more advanced users and enthusiasts, building a custom solution using microcontrollers like Arduino or Raspberry Pi is possible. These platforms can be programmed to:
- Interface with an OBD2 adapter.
- Read and process CAN bus data using libraries and code examples available online.
- Output the processed data to an HDMI display using additional hardware components or display interfaces.
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Software and Apps: While not directly “OBD2 to HDMI,” some software and mobile apps can read OBD2 data via Bluetooth or Wi-Fi adapters and display it on devices that can output to HDMI, such as smartphones or tablets connected to HDMI screens.
Technical Considerations and CAN Bus Commands
The forum post excerpt provides valuable technical insights into interacting with the CAN bus using specific commands, particularly when using an OBDLink MX adapter with the STN1100 chipset.
[Code block from forum post]
ATI (Just prints ELM 327 version ID string)
STI (Prints Firmware ID string)
STP53 (Sets Protocol to 53 - MS CAN as an example)
ATPC (Protocol Close)
ATE0 (Echo off)
ATL0 (Line Feed Off)
ATH1 (Headers On)
ATST32 (Sets timeout to 32ms)
ATS0 (Print Spaces off)
ATAT1 (Adaptive timing Auto)
ATCAF1 (Automatic Formatting On)
ATTP6 (Try Protocol 6)
ATBI (Bypass Initialization sequence)
ATAL (Allow long messages)
ATSH0007E0 (Set header to 00 07 E0 - this is typically your scan tool address if I recall correctly)
STCAFCP7E0,726 (Adds a flow control 11-bit ID pair, 7E0 is your scan tool and 726 is your target module address...you could request a known PID from the AWD module and see what header it responds with and use that going forward)These commands are crucial for establishing communication with the vehicle’s CAN bus and configuring the OBD2 adapter. They demonstrate the level of technical detail involved in directly accessing and manipulating CAN bus data. For DIY projects, understanding and potentially adapting these commands might be necessary depending on the chosen hardware and software.
[Image of a smiley face from the original post, if relevant to the general tone of technical advice, though not directly related to HDMI]
It’s important to note, as the original poster advises, “take the above with a grain of salt and maybe experiment a bit! (But don’t go too crazy. )” Working with vehicle CAN bus systems requires caution and a good understanding of the underlying technology.
Conclusion: Displaying OBD2 Data on HDMI Screens
Connecting OBD2 to HDMI opens up exciting possibilities for displaying real-time vehicle data in custom dashboards or monitoring systems. While a direct connection isn’t possible, various solutions, from dedicated adapters to DIY projects, allow you to bridge the gap. Understanding the fundamentals of OBD2, CAN bus communication, and the technical commands involved is essential for successfully displaying your car’s data on an HDMI screen. As technology evolves, we can expect even more user-friendly and sophisticated OBD2 to HDMI solutions to emerge, empowering car enthusiasts and professionals alike to harness the wealth of data available within their vehicles.
