Freematics ONE is an all-in-one and easy-to-start vehicle telematics prototyping platform. Like its predecessors, Freematics ONE comes in form of a OBD-II dongle which plugs into a car’s OBD-II port, in which, ATmega328 works as main controller connected with various peripherals giving easy access to OBD-II, GPS, 9DOF motion sensor etc with the help of a dedicated Arduino library.


  • Based on original 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
  • Analog signal input
  • GPS positioning (by external GPS receiver)
  • Data storage on microSD card (up to 32GB)
  • Exchanging data with other devices by USB or BLE
  • Low power mode @10mA

Typical Applications

  • OBD-II and/or GPS data logger
  • OBD-II data reader for mobile Apps (BLE)
  • Vehicle tracker/telemeter over GPRS
  • 9DOF motion sensing

Hardware Facts


  • ATmega328p main controller
  • STM32 based OBD-II solution (CAN BUS, K-line, NMEA parsing)
  • MPU-9250 MEMS motion sensor
  • CC2541 BLE module (optional)
  • Self-popping microSD slot
  • xBee socket for pluggable wireless communication modules
  • G7020 5Hz GPS receiver (external)
  • Enclosure dimensions: 60x48x20mm

Physical Interfaces

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

OBD-II Compatibility

Freematics ONE plugs into the OBD port usually located under the steering column. 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 500Kbps/11bit
  • CAN 250Kbps/29bit
  • CAN 250Kbps/11bit
  • KWP2000 Fast
  • KWP2000 5Kbps


Freematics ONE supports geo-location positioning by external GPS receiver. GPS receiver is connected to Freematics ONE’s I/O socket by Molex connector.

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) or a SIM800L bee adds GSM/GPRS support. For 3G network connectivity, we recommend Freematics ONE+.

BLE Module

Freematics ONE has an optional embedded BLE module (TI CC2541) which allows transparent serial data communication over BLE.

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. We supply head-less (no OBD-II header) or bear PCB versions. Please contact for details.


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
OBD-II proxy connection SPI Serial UART N/A


Shipping List

  • Freematics ONE x 1
  • Micro USB cable x 1
  • Wireless module x 1 (optional, plugged-in)
  • G7020 5Hz or M8030 10Hz GPS Receiver x 1 (optional)




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