RevDash
Getting started
Adapters
Any ELM327-compatible adapter RevDash can open a socket to: Bluetooth Classic, BLE, or Wi-Fi. There is no approved-hardware list and nothing to unlock. USB is not supported.
Bluetooth Classic and BLE
On the Adapters screen, tap Scan. Pick the dongle. RevDash binds it to the active vehicle profile and remembers the protocol it settled on, so the next connection is one tap, Retry on the dash, or it reconnects from the preferred adapter.
Classic and BLE are different radios. A dongle that only speaks Classic will not appear in a BLE-only scan, and the reverse. If the list is empty, the usual causes are Bluetooth off, location permission refused on an Android version that still requires it for discovery, or the adapter still sitting in another phone’s pairing list.
Wi-Fi
A Wi-Fi ELM327 is its own access point. It has no internet, which is why Android warns you about that, join it anyway. Then, in RevDash, tap Add Wi-Fi adapter rather than Scan. Scanning cannot find these; they do not advertise a useful Bluetooth name.
Type the address printed on the adapter, or pick a common one. If you omit the port,
RevDash uses 35000, which is what almost every clone listens on. A name is
optional. Saved Wi-Fi adapters can be forgotten from the list; Bluetooth ones come back
on the next scan, so there is no Forget for those.
| Common address | When you see it |
|---|---|
192.168.0.10:35000 | Most cheap clones |
192.168.0.10:23 | Same host, telnet port |
192.168.1.5:35000 | Some rebadged units |
192.168.4.1:35000 | ESP-based firmware |
Join the adapter’s Wi-Fi first. A timeout with the phone still on your home network is the single most common way a working Wi-Fi dongle gets declared broken. While you are connected to it, the phone has no internet. That is expected.
Vehicle profiles
Settings holds one or more vehicles. Each has a name, a preferred adapter, a protocol hint, a fuel type, and its own dash layout. The adapter is not global: a BLE dongle in the Polo and a Wi-Fi dongle in the van stay on their own profiles.
You cannot delete the last profile. Rename in place; the name is what the trip list
uses as vehicleId when you upload.
Protocol
Default is Auto. If the adapter finds the ECU once and then loses it on the next start, lock the protocol the Diagnostics screen reported (ATDPN) instead of asking it to search every time. The hints RevDash knows:
| Label in Settings | Family |
|---|---|
| Auto | Let the ELM try |
| J1850 PWM / VPW | Older Ford / GM |
| ISO 9141, KWP 5-baud, KWP fast | ISO / Keyword Protocol |
| CAN 11/500, CAN 29/500, CAN 11/250, CAN 29/250 | Modern OBD-II CAN |
| J1939 | Heavy-duty CAN |
What the chip actually means
| Chip | Meaning |
|---|---|
| Connecting / Initializing | Opening the socket, then AT init. |
| Ready | The ECU answered. Gauges should move. |
| Couldn’t reach adapter | No socket. Wrong radio, out of range, Wi-Fi not joined, or the dongle is dead. |
| Adapter OK, no ECU | The ELM answered AT commands; the car did not. Ignition off is the usual cause. |
| Bluetooth is off | The radio is disabled. Settings can prompt Android to enable it. |
| permission denied | Bluetooth or (for scan) location was refused. |
Diagnostics shows the banner, the ATSP that was sent, the ATDPN the adapter reported,
battery voltage via ATRV, and the command that failed. That screen is how
you tell a cheap clone that never finishes init from a car that is asleep.
What RevDash will not do
- USB adapters.
- Wi-Fi adapters that are a station on your home network rather than their own AP. The phone has to join the adapter.
- Talk to ABS, SRS or body modules over generic OBD-II. They are not on that bus.