Freematics ONE+ is our most powerful Arduino programmable vehicle telematics prototyping platform, an enhanced version of Freematics ONE, in form of a OBD dongle that plugs into a vehicle’s OBD port and works as a standalone data logging or edge computing device having access to vehicle’s ECU, high-rate GNSS, 9-DOF motion sensor and possibly some external sensors. Collected data can be processed in real-time, stored in internal Flash or microSD card and transmitted via BLE, WiFi or cellular network. The beauty about being open-source hardware is that it comes with SDK (Arduino libraries) and firmware (Arduino sketches) which are constantly being improved.


  • Dual-core ARM SoC processor programmable as Arduino
  • High performance WIFI and Bluetooth communications
  • G-force measurement and motion/orientation detection
  • High update rate GPS/GLONASS geolocation
  • Access to all standard OBD-II PIDs, DTC, VIN from vehicle ECU
  • Car battery voltage reading
  • Data storage in internal Flash or microSD card (up to 64GB)
  • Real-time data transmission over WiFi or cellular network
  • Working out-of-box as OBD/GPS/motion data logger (on microSD card)


Hardware Facts


  • Espressif ESP32 main controller (fully programmable)
  • Built-in 802.11 b/g/n HT40 Wi-Fi transceiver
  • Built-in dual mode Bluetooth (classic and BLE)
  • STM32 protocol co-processor
  • MPU-9250 motion sensor
  • M8030 10Hz GPS receiver (external)
  • xBee seat for pluggable wireless communication modules (SIM800L or SIM5360 for cellular network)
  • Enclosure dimensions: 60x48x20mm
  • Typical power rating @80Mhz: 20mA (WIFI inactive) / 50mA (WIFI active) / 180mA (3G active)

Physical Interfaces

  • OBD-II male connector
  • microUSB port
  • microSD card slot
  • SIM card slot (when cellular module is present)
  • GPIO socket (Molex)
  • xBee socket (onboard)

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 250Kbps/29bit
  • CAN 500Kbps/11bit
  • CAN 250Kbps/11bit
  • KWP2000 Fast
  • KWP2000 5Kbps

External I/O

Freematics ONE+ has an external I/O socket on its enclosure. The 4-pin socket contains of 2x GPIO (from ESP32), VCC and GND.  A 2.54 Molex connector is used for wiring. The line definition of the connector is as following.

  1. GND
  2. GPIO32 / Rx2 (ESP32)
  3. VCC (5V)
  4. GPIO33 / Tx2 (ESP32)



Freematics ONE+ supports high-accuracy geolocation positioning with an external GPS receiver connected to the 4-pin GPIO connector. The optional M8030 10Hz GPS receiver provides high accuracy (up to 2 meters) and high update rate (10Hz). The receiver has a 1.5m long cable and can be conveniently located where exposed to open sky.



Freematics ONE+ has a microSD slot under the side cover. The card reader is connected to ESP32 through SPI. Standard Arduino SD library can be used for microSD card access.

Cellular Module

Cellular module is attached to Freematics ONE+ through its onboard xBee socket. We provide several options of cellular modules for different networks. Following chart compares the 3 types of cellular modules currently available.

SIM800L SIM5360E SIM5360A
GSM/GPRS Quad-band
GSM/EDGE N/A Quad-Band
N/A Dual-Band
Power Consumption 2W @ 850/900MHz
1W @ 1800/1900MHz
0.25W @ UMTS 900/2100
2W @ GSM850/GSM900
1W @ DCS1800/PCS1900
0.25W @ UMTS 850/1900
2W @ GSM850/GSM900
1W @ DCS1800/PCS1900
Popular Regions Worldwide Europe, Asia, Japan*, Australia* US, Canada, Japan*, Australia*

* Countries including Japan and Australia have both 3G bands in operation by different operators. Complete information is here.

When cellular network module included, Freematics ONE+ comes with built-in antenna inside enclosure. It works great in most cases. To improve cellular network signal level in areas with poor coverage, there is an option of external antenna connected via a SMA connector which can boost signal by 3-8dB and reduce heat generated by the cellular module. Please note that xBee socket uses 5V VCC instead of normal 3.3V.

Low-Power Mode

Freematics ONE+ 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.


The schematic is here. It is subject to change and may not always be up-to-date.


Freematics ONE+ vs Freematics ONE

Freematics ONE+ Freematics ONE
Programmable Processor 32-bit Dual-Core ARM @ 240Mhz 8-bit AVR MCU @ 16Mhz
Real-time Operating System FreeRTOS (multi-threading) N/A
Development Environment Platform IO, Arduino IDE etc. Platform IO, Arduino IDE etc.
Arduino Library Features OBD-II/GPS/MEMS access,
networking, data storage, BLE GATT server
WIFI Built-in 802.11 b/g/n (SDK) Optional by ESP8266 module (AT-command)
Bluetooth Built-in BLE+BT (SDK) Optional by CC2541 module (serial)
External I/O 2x 3.3V GPIO for digital I/O, analog input, serial UART 2x 5V digital I/O or analog input
Cellular Module GSM/GPRS/WCDMA bee module, direct access (UART1) GSM/GPRS bee module, accessed by proxy chip
Program Space 4MB or 16MB Flash + 520KB RAM 32KB Flash + 2KB RAM
Data Storage microSD or built-in Flash microSD
Device LED Dual LED, GPIO controlled + communication indicator Communication indicator
Suitable Applications Real-time processing and logging for massive data sampled at high rate, low-latency data transmission with various protocols over BLE, WIFI or 3G network Local data logging and simple data transmission over BLE, WIFI or GPRS



The most exciting thing about this product is that you can create your own unique product or solution on top of our massive accomplished work. We have been developing and maintaining a dedicated  Arduino library for easy access to all hardware resources and a set of fully functional reference Arduino sketches for this product. So there is no need to start from scratch. As long as you have some basic knowledge about Arduino, you are good to go. Together with our Freematics Arduino Builder which allows configuring, compiling and uploading Arduino sketches in one simple GUI, we intend to bring the best out-of-box experience for non-professional developers. If you are a pro, we recommend PlatformIO IDE as development environment and our reference code is organized as PlatformIO projects as well, though you can still use Arduino IDE or Arduino makefile with ESP-IDF. For more information about development, please refer to the Developers Guide.


Branding & Customization

We provide firmware customization and technical support for application integration.

We supply white label or custom label enclosure. We can also supply head-less version (without OBD connector) for hard-wiring and permanent installation. With a MOQ, we can customize PCB and add/remove features to adjust the cost. Please contact for free consultation.


Shipping List

  • Freematics ONE+ x 1
  • Micro USB cable x 1
  • M8030 10Hz GPS Receiver x 1 (optional)
  • SIM800 or SIM5360 x1 (optional, plugged-in)




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