Quick Start Guide for OBU-352 Family

1. Objective

The purpose of this document is to provide necessary information to help setup and installation of OBU-352 series product. To provide for safe installation and operation of the equipment, read the safety guidelines at the beginning of this manual and follow the procedures outlined in the following chapters before connecting power to OBU-352. Keep this operating manual handy and distribute to all users, technicians and maintenance personnel for reference.

2. Reference

• Unex OBU-352 datasheet
• Unex EVK-352 datasheet
• OBU-352 drawing 61-00020-00
• Unex’s documentation (in Unex’s software release package)

3. Limited Warranty Policy

Unex Technology Corporation selling the product warrants that commencing from the date of shipment to customer and continuing for a period of twelve (12) months. This limited warranty extends only to the original customer of the product. Customer’s sole and exclusive remedy and the entire liability of Unex under this limited warranty will be, at Unex’s option, return for repair to Unex’s repair center with freight and insurance prepaid or shipment of a replacement within the warranty period or a refund of the purchase price if the hardware is returned to Unex. Unex’s obligations hereunder are conditioned upon the return of affected hardware in accordance with Unex’s service center’s then-current Return Material Authorization (RMA) procedures.

This warranty does not cover:

• Products found to be defective after the warranty period has expired.
• Products subjected to misuse or abuse, whether by accident or other causes. Such product conditions will be determined by Unex at its sole and unfettered discretion.
• Products damaged due to a natural disaster, including but not limited to lightning, flooding, earthquake, or fire.
• Software products.
• Products dismantled or opened by unauthorized persons. Please contact a representative of Unex if you need advanced technical support.
• Products with an altered and/or damaged serial number.
• Loss of data or software.
• Products that have been updated, reworked, or improperly tested by the Customer, or by a third party at the request of the Customer.
• Customized and original design manufacturer (ODM) products. The warranty terms for customized and ODM products should be defined in the contract that governs the project.

4. Safety Guidelines

• Keep working area clean and dry while assembling/installing.
• When operating under extreme temperature conditions, environmental control measures (e.g., heating, cooling) should be considered.
• It is suggested to connect the metal enclosure to a well-grounded metal structure (i.e., vehicular chassis).
• Make sure every accessory has been fastened, including the V2X antennas, GNSS antenna, Ethernet cable, and I/O cable.

5. Product Appearance

An OBU-352 series package contains the following items:

• OBU-352 x1
• V2X antenna x2
• GNSS antenna x1
• Mini-USB Y-cable x1
• USB charger x1

Besides the standard OBU-352 package, an EVK-352 series package also contains the following items:

• I/O conversion cable (EX-46) x1
• I/O conversion board (EX-47) x1

The photos shown in this document may seem different from actual product. However, the differences do not affect actual functionalities.

6. Functional Block Diagram

7. Electrical Characteristics

7.1. Absolute Maximum Ratings

Over operating free-air temperature range (unless otherwise noted).

7.2. Recommended Operating Conditions

Over operating free-air temperature range (unless otherwise noted).

7.3. Power Consumption

OBU-352 can be powered from a DC power source (e.g., automotive ACC) or from a mini-USB Vbus power source. OBU-352 will automatically switch to the power source with the highest input voltage. Changing power source can be done any time before and during operation, however a reset may be triggered during switch.

8. I/O Interfaces

8.1. OBU-352

8.1.1. External Interfaces

8.1.1.1. LED

8.1.1.2. USB0

USB0 (CN2) on OBU-352 is a USB 2.0 dual role device which can act as either a USB device or a USB host. The connector of USB0 is mini-B.

When connecting to a computer or a USB charger with a regular mini-USB cable, OBU-352 acts as a USB device and is powered by the external Vbus. However, when connecting to another USB device (e.g., USB flash drive) with a mini-USB OTG cable, OBU-352 acts as a USB host and starts providing 5V Vbus power to the USB device up to 900mA.

The power input/output is determined by the hardware design of the OTG cable. However, setting of the USB mode and detection of external device should be implemented by the user.

The EX-51 mini-USB Y-cable is provided to feed USB bus power and to allow USB 2.0 connection from a host system. While the type A connector P1 provides both bus power and USB 2.0 high-speed signal wires, the type A connector P2 only provides bus power without signal wires. The USB PSU (power supply unit) can be connected to P2 if the host USB port Vbus current supply capability is limited.

8.1.1.3. Ethernet

OBU-352 has one Gigabit Ethernet port which supports 10/100/1000 Mbps connection. It is suggested to use an Ethernet cable compatible with Cat5e or above standard for best connection speed. The connector type should be RJ45 (TIA/EIA 568B).

The Ethernet port also acts as a 12W PoE (802.3af) PD (powered device) with an add-on PoE module, POE-301. It supports both mode A and mode B PSE (power sourcing equipment). POE-301 is not included in product package and should be ordered separately if needed. Passive PoE is not supported.

8.1.1.4. I/O Port

The I/O port (J8) is the main interface of OBU-352 for console, in-vehicle networks and peripherals. The I/O port connector is JST SM20B-CPTK-1A-TB, and the mating cable connector is JST 20CPT-B-2A (see FIGURE 11: I/O PORT CABLE CONNECTOR). A cable assembly with 24AWG wire should be used to connect to vehicular wire harnesses.

8.1.1.5. 5.9GHz V2X

OBU-352 provides two 5.9GHz V2X antenna connectors. Receptacle (jack) connectors are FAKRA-Z. User should connect a pair of V2X antenna to this port directly or with a pair of FAKRA-Z plug extension cables. A pair of FAKRA-Z V2X antennas (EX-55) are provided in product package.

The V2X antenna ports has a built-in antenna detection function. This detection mechanism only works with the stock EX-55 antennas provided.

8.1.1.6. GNSS

OBU-352 provides one GNSS antenna connector. This GNSS antenna port is compatible with both passive and active GNSS antennas. The receptacle (jack) connector is FAKRA-C. User should connect a GNSS antenna to this port with a FAKRA-C plug cable. A FAKRA-C active GNSS antenna is provided in OBU-352 package.

For stable fix acquisition, at least 4 satellites with enough signal strength (C/N₀ value above 30 dB-Hz) are required. If the signal strength goes below 30 dB-Hz, the fix will become unstable.

8.1.1.7. GNSS Antenna Detection

The antenna detection mechanism is a 2-step process: First check the signal strength. If the signal strength drops to zero, then check the antenna status flag.

When all the C/N₀ values becomes null, it means that the GNSS antenna or its cable may either become detached or damaged. The GNSS antenna port has a built-in antenna detection function. The detection mechanism is based on the current consumption of an active antenna (I_ANT). If the active antenna consumes less current than 12 mA, then it is considered as the OPEN status; if the antenna consumes more than 58 mA, then it is considered as the SHORT status. Anything between 12-58 mA is considered as the NORMAL status.

The GNSS 3.3V antenna bias will be continuously supplied in OPEN/NORMAL status. Once the SHORT status is triggered, the SHORT flag will persist, and the 3.3V bias will be turned off until the reset of the GNSS module. After the reset of the GNSS module, the detection process will start all over again.

It is possible for a good active antenna to be reported OPEN because it consumes less current than 12 mA, or a good passive antenna to be considered SHORT because it is DC shorted (e.g., a slot antenna). However, as long as there are more than 4 satellites with enough signal strength (C/N₀ value above 30 dB-Hz), the GNSS is in good state.

The antenna status flag is reported in a proprietary NMEA message:

where <status> can be:

• 0 – The antenna current is in the normal range (NORMAL)
• 1 – The antenna current is below the normal range (OPEN)
• 2 – The antenna current is above the normal range (SHORT)

8.1.2. Internal Interfaces

8.1.2.1. Mini PCIe Port (Optional)

A USB 2.0 device with mini PCIe form factor can be connected to the mini PCIe port (J6). However please note that although the form factor is mini PCIe, the PCI Express interface is not available.

8.1.2.2. SIM Slot (Optional)

If a WWAN (LTE) module is connected to the mini PCIe port, the sim card should be installed. The SIM slot has a metal flip lid. It is necessary to slide the lid into “Unlock” position before open it.

8.1.2.3. Tamper Detection (Optional)

The tamper detection function will be supported by project base. It is disabled by default.

The OBU-352 has to be powered up for the tamper detection function to work. The design and implementation of a backup power source is not in the product scope and should be considered by the user.

J5 consists of 1.5mm pitch PTHs (Plated Through Holes) reserved for tamper detection function. For connecting the tamper signal, tamper signal wires can be soldered directly into PTHs. (Wires with JST 7P-SZN 1.5mm pitch board-in connector can be handled more easily when soldering.)

Pulling the tamper detection pin to ground will trigger a tamper event, indicating that the enclosure of the system has been opened without proper authorization.

The tamper detection mechanism is part of the FIPS 140-2 Level 3 security requirements. The tamper detection itself is carried out entirely in HW. On SW level, there is only an API that allows enabling the tamper detection mechanism. Calling this API will move tamper HW state from the testing mode to the production mode. Once called, it cannot move back to the testing mode.

The trigger mode of tamper detection signal can be selected with the DIP switch SW3.2. If a SOM-300 family module is added to the mPCIe port, it is possible to tie the tamper signal of SOM-300 family module and OBU-352 together. In this case, it can be selected with the DIP switch SW2.2. For more information, please see 8.1.2.5 DIP SWITCH SETTINGS for details.

8.1.2.4. SAR ADC

J4 consists of 1.5mm pitch PTHs (Plated Through Holes) reserved for SAR ADC (Successive-Approximation-Register Analog-to-Digital Converter) function. For connecting the ADC signal, ADC signal wires can be soldered directly into PTHs. (Wires with JST 6P-SZN 1.5mm pitch board-in connector can be handled more easily when soldering.)

8.1.2.5. DIP Switch Settings

8.2. I/O Conversion Board (EVK-352 Series Only)

An I/O conversion board (EX-47) and an adapter cable (EX-46) is included in EVK-352 series package. The I/O conversion board (EX-47) is an accessory which converts the JST 20 pin headers into industrial standard connectors which are more familiar to users. The adapter cable (EX-46) should be connected between EVK-352 and EX-47.

The EX-46 and EX-47 are not included in OBU-352 package and should be ordered separately if needed.

8.2.1. Console

Console is a RS232 DCE (Data Communication Equipment).

8.2.2. Ext GNSS

Ext GNSS is a RS232 DTE (Data Terminal Equipment). If an external GNSS source can output NMEA sentences over RS232, this is to port to connect. Please note that software integration of GNSS protocol will be needed for proper functionality. Contact Unex representative for more detail.

8.2.3. CAN0

If CAN0 termination jumper caps (JP1/JP2) are closed, a pair of 60 Ω termination resistors (total 120 Ω) are added to CAN0 port. If jumper caps are removed, the termination resistors are disconnected.

8.2.4. CAN1

If CAN1 termination jumper caps (JP3/JP4) are closed, a pair of 60 Ω termination resistors (total 120 Ω) are added to CAN1 port. If jumper caps are removed, the termination resistors are disconnected.

8.2.5. USB1

8.2.6. GPIO

8.2.7. DC Power Jack

Input power range is DC 6-42V. Suggested power is 12W or higher.

8.2.8. Reset Button

Pushing the reset button can reboot Linux system.

9. Dimensions and Weight

10. Software Settings

The following BSP settings are applicable for Unex software package only.

11. Troubleshooting

11.1. No Response After Applying Power

This phenomenon may come from multiple causes. Please follow the steps below to check each one of them:

1. Check if the DC power have been properly supplied by your motherboard. An alternative power source is to connect USB0 Vbus to a host machine or a power supply.
2. Check if the PWR LED is turned ON.
3. Connect the UART console to your host.
   1. If CRT2 shows after 60 seconds, then it means bootable image not found on the NAND.
   2. If nothing shows after 60 seconds, then it could mean one of the following issues:
      1. Somehow the RESET pin (J8.2) is hold LOW. Check for possible shorts in I/O port cable or wire harness.
      2. DC power voltage too low, or the power source impedance too high.
      3. Hardware damage.
4. Connect USB0 to your host. Check if the RNDIS driver has been properly installed on your host system.
5. Check if the IP address 192.168.1.1 has been assigned to another network interface on your host system. If it has already been assigned, it is required to perform either of the following operations:
   1. Change the IP setting of that network interface on your host system and leave 192.168.1.1 available for the OBU-352 / EVK-352 family RNDIS interface.
   2. Change the OBU-352 / EVK-352 family RNDIS IP address setting. Please refer to the CHANGING SYSTEM IP ADDRESS section in Unex’s documentation, which can be found in Unex’s software release package.

11.2. No TX/RX Activities during Over-the-Air Testing

1. Check the antenna status of both V2X antennas on the TX node and the Rx node.
   1. If Unex’s V2X antennas EX-55 are used, use the V2X antenna detection commands listed in TABLE 24: UNEX BSP INTERFACE SETTINGS. For OPEN/SHORT value range, please see TABLE 9: V2X ANTENNA STATUS.

      cat /sys/bus/iio/devices/iio\:device0/in_voltage4_raw
      cat /sys/bus/iio/devices/iio\:device0/in_voltage5_raw

   2. If Unex’s V2X antennas EX-55 are not used, it is the user’s responsibility to check the antenna OPEN/SHORT status.

      Attention	Performing transmission under OPEN/SHORT conditions may cause permanent damages to RF components. Always check antenna status before any V2X TX activity.

2. For DSRC systems:
   1. Send 10 V2X packets with priority 7 in TX node.

      diag-cli <<< $'chan freq 0 5860\nv2x send 0 0 0 400 10 10 7 160\nstats\nexit' 2>/dev/null

      
   2. Check MAC/PHY statistics in RX node.

      diag-cli <<< $'chan freq 0 5860\nstats\nexit' 2>/dev/null

      
3. For C-V2X systems:
   1. CCheck GNSS antenna and GNSS health status. C-V2X requires GNSS time synchronization and TSF (Timing synchronization function) synchronization with GNSS 1PPS before any transmission.
      1. Make sure the very same /usr/bin/cv2x_rrc_config.uper and /usr/bin/cv2x_sw_config.txt are uploaded on both TX and RX nodes.
      2. If the OBU-352 / EVK-352 comes with Unex’s C-V2X protocol stack, then use gnss_health command to check the overall GNSS system healthiness. ACL_TIME_SYNC_SYNCED means the access layer (i.e., the TSF timer) has been successfully synchronized.
      3. If the OBU-352 / EVK-352 comes without Unex’s C-V2X protocol, then use the following commands:
         1. Check the GNSS antenna status and fix mode. For GNSS antenna status, please see GNSS ANTENNA DETECTION; for GNSS fix mode, please check the 2nd field of GSA sentence: $GNGSA,A,3,24,15,10,23,12,32,,,,,,,2.6,1.4,2.1*2E Fix Mode: 1 = Fix not available; 2 = 2D fix; 3 = 3D fix.
         2. Check 1PPS status.

            watch -n 1 grep pps /proc/interrupts

            

            If the pps1.-1 count is increasing, then the 1PPS is working.

         3. Check TSF synchronization status.

            diag-cli <<< 'ddm tsf get' 2>/dev/null | grep =

            

            If it shows TSF lock status = locked, then TSF is synchronized.

   2. IfIf the OBU-352 / EVK-352 comes with Unex’s C-V2X protocol, stop Unex’s V2X services on both TX and RX nodes before running cgen command.

      d=/etc/runit/svdir/;svstop(){ [ -e $d$s ] && sv stop $d$s; }; 
                          for s in v2xcastd ssmed ssmd dot3d gnd;do svstop;done

   3. Clear MAC/PHY statistics on the RX node.

      ccd /usr/bin;cgen freq=5915 run=cyq 2>/dev/null

      
   4. Send 10 V2X packets from the TX node.

      cd /usr/bin;cgen power=40 freq=5915 num=10 run=wwwcgtwzq 2>/dev/null

      
   5. Check MAC/PHY statistics on the RX node.

      cd /usr/bin;cgen freq=5915 run=yq 2>/dev/null