SAE J1939 - GPS Module With 9-Pin Deutsch Connection Cable

The jCOM.J1939.GPS device connects to an SAE J1939 network and reports the vehicle position (PGN 65267) with a five second frequency, according to the SAE J1939-71 Standard. The integrated J1939 protocol stack automatically negotiates a node address in the range of 128 to 247. The GPS data is broadcast by using the global destination address (255 = 0xFF). The device's firmware can be updated on-site per the integrated RS232 port, which also allows the loading of customer-specific features.

The content of delivery includes the jCOM.J1939.GPS module, the GPS antenna (preferred installation location is the driver cabin, i.e. close to the wind shield), and the SAE J1939 cable suited for a 9-pin Deutsch connection. 

New!

Starting with firmware version 2.0, the  jCOM.J1939.GPS device responds to requests for Time & Date (PGN 65254) and Vehicle Direction & Speed (PGN 65256).

Features

• ARM Cortex-M3 Processor
• CAN Bus Interface - Fully ISO-11898 Compliant
• RS232 Interface For On-Site Firmware Upload and/or Gateway Functionality
• GPS module with external antenna
• SAE J1939 Protocol Stack
• Extended Temperature Range of -40C to +85C
• Input Power Range of 7 VDC to 36 VDC
• Flame Retardant ABS Enclosure 4.25 x 3.00 x 1.38 in / 107.95 x 76.20 x 35.05 mm
• Environmentally friendly, RoHS compliant

Specifications

• CAN Interface
• CAN Controller integrated in microcontroller
• Fully ISO 11898-compliant
• Supports CAN 2.0A And CAN 2.0B
• Bit rate detection 250/500 kBaud
• GPS
• Receiver type: 56 channels, GPS L1(1575.42Mhz) C/A code, SBAS:WAAS/EGNOS/MSAS
• Horizontal position accuracy: 2.5mCEP 
• Navigation update rate:5 Hz maximum (1HZ default)
• Capture time: Cold start: 27s (fastest)；Hot start: 1s
• SAE J1939 Protocol Stack
• Fully compliant to SAE J1939/21, SAE J1939/81 and SAE J1939/16
• Sending and receiving of messages (PGNs)
• Message filtering
• Request message processing
• BAM and CM transport protocol (TP) processing
• Static and arbitrary address claim
• Automatic CAN baud rate detection (250/500 kbit/sec) 

For a complete user manual and applicable firmware update information, please visit the Copperhill Technologies Wiki website.

User Manual
Hardware
Firmware Versions & Update

Please feel free to contact us, in case you need any additional or modified functionality. We can provide solutions within shortest time, and we don't charge when the modifications are minor or help to improve our product.

Automatic CAN Baud Rate Detection

The jCOM.J1939.GPS device provides automatic CAN baud rate detection, which requires some special attention when connecting the device to a network. For more information see our post:

• How CAN Bus Automatic Baudrate Detection Works And What To Consider When Connecting To A Network

PGN 65267 - Vehicle Position

The output of the application is PGN 65267 (0xFEF3) according to the SAE J1939-71 standard:

Transmission Rate: 5 s
Data Length: 8 bytes
Default Priority: 6

SPN 584

Resolution: 10^-7 deg/bit, -210 deg offset
Data Range: -210 to 211.1008122 deg
Operational Range: -210 deg (SOUTH) to 211.1008211 deg (NORTH)

SPN 585

Resolution: 10^-7 deg/bit, -210 deg offset
Data Range: -210 to 211.1008122 deg
Operational Range: -210 deg (WEST) to 211.1008211 deg (EAST)

GPS Data

The image below demonstrates the data output of the GPS module (CAN/J1939 port).

Line 1 documents the address claim. The application is set up for an address range between 128 (0x80) and 247 with a preferred address of 128. The following lines are valid GPS data (pointing to our Windows 10 PC in our office; we moved the board as far as the cable allowed and changes are visible). 

Please note that the SAE J1939-71 Standard uses Small Endian for data transmission, meaning LSB comes first, MSB comes last. Also be aware, it might take several minutes after startup before the GPS module can provide a valid position (Once found, it takes only seconds with clear reception). The SAE J1939-71 Standard does not cover such a scenario, i.e. the data output for such a case is not defined. Rather than not sending anything at all, we chose to set all 8 data bytes to 0xFF.

Firmware Updates

In order to allow on-site firmware updates, we have created a simple Windows program that enables the user to initiate the programming procedure (i.e. switching to FLASH mode).

Note: You will need a USB-to-RS232 adapter to connect the GPS module to your PC. Any standard adapter will do, but we also recommend using a standard straight RS232 cable, since some of these adapters use hex screws that collide with the RS232 port. 

Recommended cables:

• USB to RS232 DB9 Serial Adapter Cable...
• Straight Through DB9 RS232 Serial Cable...

As shown above, the Windows software serves not only as a firmware updating tool, it also displays the current position, serving as a proof of concept.

• Click here to download the Windows installation program (msi)...

Checking the Firmware and Windows Programming Tool Versions

In order to check the program versions of either the GPS module's firmware or the Windows programming tool (or both), start the Windows program and initiate the connection to the module by clicking on Start COM. Shortly thereafter, the firmware version will be updated on the screen (as shown above using the example "jCOM.J1939.GPS - Firmware Version 1.00.00"). The Windows program version in this example is shown in the upper left corner as "jCOM.GPS - V 1.00.00."

Firmware Versions

• Click here to determine and download the newest firmware version...

Windows Programming Tool Versions

• Version 1.00.00
• Initial Release

CAN Bus Termination Resistor

The jCOM.J1939 comes per default with a 120 Ohm termination resistor activated. To deactivate the resistor, open the enclosure and locate the DIP switch as indicated in the following image.

Serial Interfaces