Freematics ONE (aka Freematics Vehicle Data Logger V4) is our state-of-the-art vehicle telematics data collector, adapter, logger and transmitter which evolves from our past 3 generations of Freematics Vehicle Data Logger.

Freematics ONE, like its predecessors, comes in the form of a OBD-II dongle which plugs into a car’s OBD-II port. The enclosure is newly designed with sockets and card slots for various purposes around it. We improved our original 32-bit OBD-II telematics solution, which has been proven in our previous OBD-II products, with better support for high data rate GPS and additional support for wireless network modules.

Freematics ONE+, an enhanced version of Freematics ONE, is now available for order!


  • Based on the OBD-II solution from Freematics OBD-II Adapters
  • Programmable as an Arduino UNO
  • Access to all standard OBD-II PIDs, DTC, VIN from vehicle ECU
  • G-force measurement and motion/orientation detection
  • Measuring car battery voltage with built-in voltmeter
  • High update rate GPS positioning (by external GPS receiver)
  • Storing data on microSD card (up to 32GB)
  • Exchanging data with other device by USB or BLE
  • Low power mode @10mA


Hardware Facts


  • ATmega328p main controller compatible with Arduino UNO
  • STM32 based OBD-II solution (CAN BUS, K-line, NMEA parsing) on SPI
  • CC2541 BLE module (optional)
  • MPU-9250 9-DOF MEMS sensor
  • Self-popping microSD slot
  • xBee socket for pluggable wireless communication modules
  • External GPS receiver
  • Enclosure dimensions: 60x48x20mm

Physical Interfaces

  • OBD-II male connector
  • microUSB port
  • microSD card slot
  • GPS connector (Molex)
  • xBee socket (inside, 5V or 3.3V VCC)

BLE Module

Freematics ONE has optional TI CC2541 BLE module hooked on the hardware serial of ATMega328p.

BLE USB Dongle

BLE USB Dongle gives computer BLE connectivity. When the dongle is plugged in, a serial port will appear on computer while it automatically pairs with nearby Freematics ONE device and establish transparent serial communication wirelessly through BLE.

OBD-II Compatibility

Freematics ONE plugs into the OBD port usually located under the steering column or slightly to the left of it. To check if your vehicle is OBD-II certified, open your hood and find the sticker that looks like this:


Vehicles using following vehicle protocols are supported.

  • CAN 500Kbps/29bit
  • CAN 250Kbps/29bit
  • KWP2000 Fast
  • KWP2000 5Kbps


Freematics ONE supports high update rate geographic positioning with an external GPS receiver. The GPS connector is a Molex 4-pin connector. The GPS receiver has a 1.5m long cable and is intended to placed on top of car dashboard for optimum GPS signal reception.

UBX-M8030 GPS Receiver with Molex connector Freematics ONE GPS Connector F-ONE_3497

GPSConnectorxBee Socket

Freematics ONE has an xBee socket onboard which provides the possibility to extend its wireless communication capability with various xBee module. A ESP8266 WIFI bee adds WIFI connectivity (see this).

Low-Power Mode

Freematics enters and leaves low power mode programmatically. In low power mode with all peripherals (GPS, GSM, WIFI) powered off, the power consumption is around 10mA. This prevents car battery from going flat while the main controller is still able to run code and perform low-power tasks like motion detection by MEMS sensor.

PCB Layout

Following is the PCB layout of Freematics ONE. The schematic is here.


Firmware (Arduino sketch) can be uploaded to Freematics ONE exactly the same way as for an Arduino UNO from standard Arduino IDE through USB port. Please refer to the Users Guide for related more information.

Pre-loaded Firmware

A data logger sketch is pre-loaded before shipping, your Freematics ONE will work out-of-box as a vehicle data logger which performs following tasks:

  • Connect to the vehicle via OBD-II port
  • Connect to the GPS receiver (if available)
  • Create a new file on microSD card
  • Log OBD-II, GPS, MEMS sensor data to the file (file format)
  • Transmit live OBD-II, GPS, MEMS sensor data via USB and BLE



Freematics Vehicle Data Logger V4 (Freematics ONE) Freematics Vehicle Data Logger V3 Generic OBD-II Dongle
Arduino Compliant Yes Yes No
User Programmable Yes (via USB) Yes (via ICSP) No
Built-in MEMS Sensors 9-axis MPU-9250 6-axis MPU-6050 No
High Update Rate GPS Yes (up to 10Hz) Yes (up to 5Hz) No (or 1Hz only)
xBee Module Extension Yes (GSM, WIFI, xBee etc) No No
Mass Storage (microSD) Yes Yes Some
OBD-II Firmware Upgrade Yes No No
iOS Device Connectivity Yes Yes Some
Controllers Inter-connection SPI @ 8Mbps Serial UART @ 115.2Kbps N/A


Shipping List

  • Freematics ONE x 1
  • Micro USB cable x 1
  • M8030 10Hz GPS Receiver x 1 (optional)




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