Which ELM327 adapter to choose
Canfiti works with ELM327 adapters and compatible clones with an OBD2 plug. The connection type decides which phones the adapter works with, and its quality decides how stable the link is.
| Connection | iPhone | Android | Notes |
|---|---|---|---|
| Bluetooth Low Energy (BLE) | The universal choice: works with any phone. | ||
| Bluetooth Classic | iOS does not let apps use classic Bluetooth — Android only. | ||
| Wi-Fi | The phone joins the adapter’s Wi-Fi network. Usually the adapter accepts only one connection. |
What else matters
Adapter quality
For a stable link the author recommends a two-board ELM327 with a PIC18 microcontroller. With some cheap single-board adapters the units fail to initialize.
CAN bus only
Canfiti uses the CAN protocol (ISO 15765-4, 500 kbps). Vehicles that only offer K-line diagnostics are not supported.
Slow clones
Adapters running at 38400 baud overflow their buffer on long replies — the app works around this automatically.
How to connect
Bluetooth (BLE or Classic)
- 1Plug the adapter into the OBD2 port under the steering wheel and turn the ignition on.
- 2Turn Bluetooth on and allow the app to access nearby devices.
- 3Tap the adapter card on the main screen — “Scanning devices” starts.
- 4Pick your adapter in the list and wait while the app checks and configures it.
Wi-Fi
- 1Plug in the adapter and turn the ignition on.
- 2Join the adapter’s Wi-Fi network in your phone settings.
- 3Go back to Canfiti and open “Scanning devices” — the Wi-Fi adapter shows up first within 10–20 seconds.
- 4On Android allow location access: without it the system will not let the app connect to a Wi-Fi adapter. Turning off VPN helps.
If the adapter will not connect
- Another app such as Car Scanner, or another phone, is holding the adapter. Close them and try again.
- The iPhone does not see a Bluetooth adapter — it is probably Bluetooth Classic. You need a BLE or Wi-Fi adapter.
- Android will not start scanning: toggle Bluetooth or restart the phone, turn location on, clear the Bluetooth cache, reset network settings, turn off battery saving for the app.
- “Unit initiating error” appears — most often the adapter is to blame. Try another one, preferably a two-board adapter.
- The unit does not respond — make sure the ignition is on and your car actually has that unit.
- Update the app: version 0.6.1 made adapter connections noticeably more reliable.
Questions and answers
Which ELM327 adapter is best for iPhone?
A Bluetooth Low Energy (BLE) or Wi-Fi adapter. Classic Bluetooth adapters do not work with iPhone.
Why doesn’t Canfiti see my Wi-Fi adapter?
First join the adapter’s Wi-Fi network, then open “Scanning devices” and wait 10–20 seconds. On Android location access is required, and turning off VPN helps.
Will a cheap ELM327 clone work?
Yes, the app accepts clones. But adapter quality affects stability: two-board PIC18 adapters cause the fewest problems.
Can Canfiti and another app use the adapter at the same time?
No. The adapter serves one connection: close other diagnostic apps before connecting.