GPS to CAN bus - existing products or modules for getting started? - Page 1
Forum section: electronics / projects

author: Martin F
author_rank: Regular Contributor
timestamp: May 08, 2018, 12:11:06 pm
content: Hi there,We need to buy or build a small module that can record GPS data and send it to a CAN bus (e.g. of a vehicle or machine).We've not been able to find a solution online, but we wanted to hear if you know of any?Alternatively, we're prepared to build one from scratch - but in that case, we wanted to hear if anyone has good tips for where to start - i.e. what kind of base modules would make for a good starting point in building this?Thanks a lot,Martin

author: Rerouter
author_rank: Super Contributor
timestamp: May 08, 2018, 12:24:04 pm
content: ublox moduleConnected to micro controller of your choiceconnected to a canbus transceiver.There was someone else asking about the same kind of thing on here about 2 months ago, So i have my doubts it exists.Final note, there are standardised J1939 PID's for GPS status, e.g. lat, long, speed, etc, I would recommend you use them,

author: Martin F
author_rank: Regular Contributor
timestamp: May 08, 2018, 01:23:28 pm
content: Thanks for the ublox tip!Anyone with experience in what would be key to focus on in terms of specs for automotive use?

author: BradC
author_rank: Super Contributor
timestamp: May 08, 2018, 01:44:23 pm
content: It might be worth looking at NMEA-2000 GPS modules. They are essentially a CAN bus GPS.

author: max_torque
author_rank: Super Contributor
timestamp: May 08, 2018, 07:19:39 pm
content: Quote from: Rerouter on May 08, 2018, 12:24:04 pmOnly is you're going to run the system on a J1939 host system. Otherwise it's a massive, phaff for literally zero gain!

author: Rerouter
author_rank: Super Contributor
timestamp: May 08, 2018, 08:34:51 pm
content: For automotive retrofitting, follow the j1939 standards for what data you send, the 2014 one is available on the net.avoid the 0xFFXX propriatary range, too many manufacturers sprinkle stuff in here for no good reason.Listen for and follow the diagnostic tool "quiet" command.When a dealer diagnostic tool is plugged in to most equiptment, It will periodically send a pid telling all the other canbus nodes to stop transmitting, so as to not interruptna firmware update or settings change. Failing that is the fastest way to have a dealer cutting your device off the canbus.The only other thing is, use a good off the shelf regulator for your device, e.g. a recom that is rated for automotive use. Vehicles are horrible electrical enviroments, reguarly being jump started, running on dead batteries, etc.Fit the option of a 120 ohm termination resistor, but do not have it connected by default, preferably switchable at installation.

author: Martin F
author_rank: Regular Contributor
timestamp: May 08, 2018, 08:51:13 pm
content: Super tips, really appreciate it! Great people here at EEVblog!

author: Martin F
author_rank: Regular Contributor
timestamp: May 09, 2018, 07:15:06 am
content: I've contacted Ublox and will look into their options. Do you have other suggestions for suppliers of good value-for-money chips?Thanks!

author: Rerouter
author_rank: Super Contributor
timestamp: May 09, 2018, 08:15:22 am
content: ublox modules are one of my main go-to's for pain free R&D, for others, pull up digikey, or other online supplies in your area, and see what meets your requirements,You also need to choose on module antenna, on PCB antenna or external. (Internal / on module will be cheaper)