Adapters
Adapters play a crucial role in this type of service.
The OBD2 protocol is based on an asynchronous serial architecture and uses a standardized electrical port, typically located under the dashboard, near the driver’s seat. The adapters, sometime referred to as a “dongle”, are a small device that translates OBD2 protocols into Bluetooth, enabling wireless communication with a Smartphone running the appropriate diagnostic software.
While this may sound straightforward, the actual functionality is quite complex. These adapters must act as translators between the OBD2 system, which varies depending on the vehicle’s make, model, and production year, and the Bluetooth standard, which has evolved over time with multiple versions.
Additionally, the connection between Bluetooth and smart phones is influenced by both hardware advancements and the continual evolution of operating systems. Ensuring seamless compatibility between all these elements is critical for reliable performance.
We are working on a compatibility page, and our current “Billboard” is shaping up as follows:
MicroMechanic Dongle
✅ Bluetooth adapter
❌ Blabla…
Carista OBD2
✅ Bluetooth adapter
OBD Link MX+
✅ Bluetooth adapter
✅ iPhone
✅ Android
✅ Windows
Mini OBDII
✅ Bluetooth adapter
✅ Android
Veepeak OBDCheck BLE+
✅ Bluetooth 4.0
✅ OBD2 Scanner for iOS & Android
✅ Car Diagnostic Code Reader Scan Tool for Universal OBDII/EOBD Vehicles
Additional information about adapters
Some companies restrict their apps to work only with a specific adapter, selling both as a bundle. However, since Smartphone apps are only available through App Stores, which do not sell hardware, users must go through two separate purchasing channels to get both an app and an adapter.
Locking an app to an adapter allows companies to control total pricing. Having the adapter at a cost while making the app “free” or vice versa. In our side, we decided for a different Business model, considering that it would be like buying a cheap phone that only works with a specific network. Another good analogy would be looking at the evolution of personal computers: before PCs, companies sold word processing systems as a package (hardware, keyboard, screen, printer, and software). But with the rise of PCs, users gained the freedom to choose and switch between different word processing applications and ..also use PC’s for other usages. The market clearly favored openness and flexibility, and we believe the same should apply to OBD2 adapters and scanning apps.
There are countless OBD2 adapters available, many at very competitive prices on platforms like Amazon. We believe the best solution is to let users choose an adapter that suits their budget and needs, then select an app based on what they want to do. A fleet manager might need an app to track mileage and fuel costs, while a racing enthusiast could prefer one that analyzes lap times and performance data. Another user might want to monitor engine sensors for maintenance, prepare for an emissions test, diagnose an error, or inspect a used car before buying it.
Another key reason for keeping adapters independent is hardware evolution. Every adapter has a small CPU that translates OBD2 protocols into Bluetooth. As CPU technology advances, faster adapters improve performance. The saying in IT is: “Anything that isn’t instant is too slow.” Instead of replacing multiple adapters, we also think that it would be is more practical to upgrade just one?
The only challenge on this choice is ensuring compatibility. Above, you’ll find a compatibility table listing some of the most commonly available adapters, that we tested with both iOS and Android Smart phones.
OBD and Vehicle Diagnostics
Since 1996, all cars in the USA must have a standard OBD port for basic diagnostics like catalytic converter monitoring and fuel tank pressure checks. However, advanced diagnostics vary by brand and are often restricted to dealership service departments.
Modern cars have hundreds of sensors and up to 50 onboard computers (ECUs), tracking everything from door closures to tire pressure. Some ECUs react instantly in emergencies, like airbag deployment if a passenger is detected.
The ELM327 chip, developed by ELM, enables communication between vehicles and OBD2 adapters, allowing for diagnostics via Bluetooth and smartphone apps. However, automakers protect proprietary data, keeping some functions exclusive to dealers.
After the warranty period, drivers need reliable tools to understand check engine warnings and make informed repair decisions.
At ChkOBD, we provide a simple, accessible diagnostic tool using an OBD-to-Bluetooth adapter and a smartphone app for iOS and Android.
Learn more: Wikipedia – On-board diagnostics.