In the realm of automotive diagnostics, understanding communication protocols is crucial, especially when dealing with older vehicles. The Automotive Diagnostic Link Layer (ALDL) is one such protocol, prevalent in pre-OBD-II vehicles, and remains a topic of interest for DIY car enthusiasts and those working with classic cars. Projects focused on interfacing with ALDL systems, like the one discussed in a recent forum, highlight the ongoing relevance of this protocol and the ingenuity of the car community.
One such project, shared by a user, details the progress of developing an ALDL scanning tool using Arduino. This initiative aims to tap into the diagnostic data available through the ALDL protocol, allowing for custom readings and interpretations. The user has been diligently working on refining the serial communication aspect of their Arduino code, sharing different iterations named ardl_test3, ardl_restart, and ardl_restart2. Each version represents a step towards optimizing data collection speed and efficiency. The focus has been on streamlining the serial loop to achieve faster and more reliable readings from vehicles utilizing the A034.ds ALDL protocol.
The initial code, ardl_test3, successfully retrieves readings, achieving a commendable 119ms data retrieval time. Subsequent versions, ardl_restart and ardl_restart2, delve deeper into optimizing serial communication. ardl_restart explores Arduino-native commands, while ardl_restart2 aims to leverage serial port capabilities more effectively. Although ardl_restart2 initially takes longer to establish a connection (around 6 seconds), these experiments are crucial for understanding the nuances of ALDL communication and pushing the boundaries of DIY diagnostic tools.
Looking ahead, the project aims to develop a comprehensive ALDL library. This library would abstract the complexities of the protocol and allow users to easily integrate ALDL scanning capabilities into their own projects, without needing to hardcode vehicle-specific details. This move towards a reusable library underscores the collaborative spirit of the DIY automotive community and the desire to make diagnostic tools more accessible and adaptable. For those interested in delving into the specifics of ALDL protocol numbers and building their own scan tools, projects like this provide valuable insights and a starting point for exploration.
