# Use OBDII fleet tracker as a cellular switch?



## Hansen (Apr 27, 2017)

First, I don't know if an OBDII fleet tracker has an I/O port, but I assume it has something similar because many have the ability to disable a car.  I was hoping someone has had the experience of reprogramming one to only use as a cellular on/off switch, (control a 12vDC 100ma device). This would not be in a car.
Tanks!


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## FR@NK (Apr 27, 2017)

Yes but it may not be cost effective to use a GPS tracker if you dont intend to use it in a car.

What are you trying to do?

http://relaysupply.com/gsm-relays/3g-4g/4g-gsm-relay.html

Cost abit up front but very cheap to maintain.


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## R-T-B (Apr 27, 2017)

> Tanks!



Tanks?

...

I'm surprised they use OBDII, frankly.

What models, if I may ask? lol


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## Hansen (Apr 27, 2017)

FR@NK said:


> Yes but it may not be cost effective to use a GPS tracker if you dont intend to use it in a car.
> 
> What are you trying to do?
> 
> ...


Thanks for the post.   I have seen these devices before, but I can bye the OBDII  trackers for less than half of those because they are mass produced.  I would not be using the GPS or other features, but they are inexpensive and act as a cartridge for when I have to upgrade to 5G  in the far future.  So, you think I can actually reprogram it for a pin to act as an output to throw a positive or ground?


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## Papahyooie (Apr 27, 2017)

So you're wanting to use an OBDII tracker, so that you can send a signal to it via cellular, to switch on and off a device. Right? 

Should be doable, I don't see why you couldn't just send the signal you wish to use to it, then probe it with a mutlimeter to find out what pin you want. 

But don't those require a monthly fee per device? I don't think it's going to work without being tethered to whatever service the device is made for. As far as I know, there won't be any way to talk to it over cellular without going through whatever service the dongle is designed for.


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## Hansen (Apr 27, 2017)

Papahyooie said:


> So you're wanting to use an OBDII tracker, so that you can send a signal to it via cellular, to switch on and off a device. Right?
> 
> Should be doable, I don't see why you couldn't just send the signal you wish to use to it, then probe it with a mutlimeter to find out what pin you want.
> 
> But don't those require a monthly fee per device? I don't think it's going to work without being tethered to whatever service the device is made for. As far as I know, there won't be any way to talk to it over cellular without going through whatever service the dongle is designed for.


I can use my own sims cards without a problem. I was hoping someone has done it: if these devices can act as a remote switch. There are many manufacturers: Novatel, Calamp, etc.


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## Papahyooie (Apr 27, 2017)

Gotcha. I've never seen one with a removable sim card. I think after you've gotten the communication out of the way though, you'd have to reverse engineer the software to figure out how to get a signal out to your project. I doubt anyone has ever done that before. 

If I may ask, what are you trying to accomplish? There are many ways to get a cellular signal to a device and make it spit out a simple enough signal to pop a switch. An arduino and a cellular shield come to mind. Easy peasy. Why specifically pick an OBDII tracker?


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## Hansen (Apr 27, 2017)

They are mass produced (inexpensive) and act as a cartridge for when I have to upgrade to 5G in the far future.


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## Papahyooie (Apr 27, 2017)

Arduino has both of those points going for it as well. And when you need to upgrade to 5G, you'd just have to get a new shield. I'm not really sure how you'd upgrade to 5G on an OBDII tracker, considering those have their radios built in. (and I would assume 5G would introduce new radio hardware.) 

An arduino is inexpensive, upgradable, uses standard protocol, and most importantly doesn't have the caveat of having to reverse engineer a firmware. You could just write your own app natively. Much easier. 

I'm not trying to discourage you from using the tracker, I just don't understand the reasoning behind using it. So far, an arduino has all your requirements, and is going to be FAR easier to accomplish what you want to do.


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## Hansen (Apr 27, 2017)

I appreciate the feedback. The reason is I can buy these at far less then the Arduinio (under $80 ea), and can be easily programmed.


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## Papahyooie (Apr 27, 2017)

See, that's what I disagree with... I don't think an OBDII tracker is going to be easily reprogrammed. Once you get rid of the manufacturer's firmware, the thing isn't going to be able to just talk to the cell network, unless there's a modular one that I don't know about. Those things, while mass produced, are pretty proprietary (except for the ODBII interface of course.) Which model of tracker are you looking at?

As for arduino, you can easily buy arduinos for under $80... there are small versions that will probably do what you want for less than $10. If the more barebones versions don't do what you want, get a raspberry pi and a 4g shield. So yea... cost being a factor, you can get hobby boards at FAR less than you'll get the trackers for, and they're very much more easily customized.

I don't mean to call you into question, but why are you so adamant about using the trackers? Cost isn't a good reason to use one, ease of programming isn't a good reason... The only reason I could think for you wanting to do this is to either bypass some security, or worse... trigger a car bomb?... Like I said, I'm not trying call you into question here, but you won't tell us what you're doing with them, or give a good reason why the tracker is a better option so....


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## Hansen (Apr 27, 2017)

Papahyooie said:


> See, that's what I disagree with... I don't think an OBDII tracker is going to be easily reprogrammed. Once you get rid of the manufacturer's firmware, the thing isn't going to be able to just talk to the cell network, unless there's a modular one that I don't know about. Those things, while mass produced, are pretty proprietary (except for the ODBII interface of course.) Which model of tracker are you looking at?
> 
> As for arduino, you can easily buy arduinos for under $80... there are small versions that will probably do what you want for less than $10. If the more barebones versions don't do what you want, get a raspberry pi and a 4g shield. So yea... cost being a factor, you can get hobby boards at FAR less than you'll get the trackers for, and they're very much more easily customized.
> 
> I don't mean to call you into question, but why are you so adamant about using the trackers? Cost isn't a good reason to use one, ease of programming isn't a good reason... The only reason I could think for you wanting to do this is to either bypass some security, or worse... trigger a car bomb?... Like I said, I'm not trying call you into question here, but you won't tell us what you're doing with them, or give a good reason why the tracker is a better option so....


Yes, I have easily programmed non-OBDII trackers (Novatel SA-G, MT1200, MT4100).  I am just turning on a small pump, thanks for assuming I'm a bomber LOL. 
OBDII's: I like the cartrige design, they are certified to use on the phone carriers, and I thought for less then $80, it would be cheaper than any other 3G or 4G (raspberry Pi or arduino) and a case.  Maybe point me in a direction on where to buy something cheaper? Or, who can tell me if the OBDII has an output pin?


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## Papahyooie (Apr 27, 2017)

Hey, I just wondered lol... It didn't make any sense that you wouldn't tell us what you wanted to use it for, after being asked several times. 

Arduino GSM shields can be had for 30 bucks, and arduinos themselves are anywhere from $10 to $150 depending on what bells and whistles you want. If you only want to flip a switch, the cheapest arduinos will have plenty of power. Raspberry pi goes for 30 bucks, plus a GSM shield for 30 bucks...  And if you can reprogram a tracker, then doing it on an arduino or Pi will be child's play. 

As for the OBDII output pin, sure it does. Several of the pins are manufacturer specific, so you could re purpose one of them. That's easily found with a quick google search.


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## FR@NK (Apr 28, 2017)

Hansen said:


> I can bye the OBDII trackers for less than half of those because they are mass produced



Yea these relays are expensive up front, but the cost to use them is dirt cheap. Once you set it up, it can switch the main relay when it gets a call from the authorized number and it wont even answer so you dont get charged any air time. Total cost for the SIM card per month is only $3. I'm sure you could get a similar setup with an arduino + cellular shield.

With a OBD tracker you might need to use air time or SMS. Some of them even require a data plan on the SIM card. This could raise the monthly expense well beyond $3.



Hansen said:


> Or, who can tell me if the OBDII has an output pin?



The OBD port just has data and power pins. You wont be able to use any of these pins to activate a relay.


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## Hansen (Apr 28, 2017)

FR@NK said:


> Yea these relays are expensive up front, but the cost to use them is dirt cheap. Once you set it up, it can switch the main relay when it gets a call from the authorized number and it wont even answer so you dont get charged any air time. Total cost for the SIM card per month is only $3. I'm sure you could get a similar setup with an arduino + cellular shield.
> 
> With a OBD tracker you might need to use air time or SMS. Some of them even require a data plan on the SIM card. This could raise the monthly expense well beyond $3.
> 
> ...


 Are you   100% sure? On all models?


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## FR@NK (Apr 28, 2017)

Very Shirley.


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## Papahyooie (Apr 28, 2017)

Some of those fleet trackers have the ability to shut down the car though. Why wouldn't one be able to grab that signal to activate a relay?


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## Hansen (Apr 28, 2017)

That's what I was hoping. 
I saw this:
Standard PID (see Hex 65 in chart: Says Auxillary input/output, so I hope it can throw positive or negative to control my 12vDC 100ma device.)


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## FR@NK (Apr 29, 2017)

Papahyooie said:


> Some of those fleet trackers have the ability to shut down the car though. Why wouldn't one be able to grab that signal to activate a relay?



There are more expensive ones that will disable the starter, but they dont do that over the OBD2 port. They have a separate relay that you wire into the starter solenoid(or equivalent).



Hansen said:


> That's what I was hoping.
> I saw this:
> Standard PID (see Hex 65 in chart: Says Auxillary input/output, so I hope it can throw positive or negative to control my 12vDC 100ma device.)



Thats a data input/output...The OBD port just has data and power pins. You wont be able the OBD port to activate a relay.


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## jboydgolfer (Apr 29, 2017)

Hansen said:


> thanks for assuming I'm a bomber


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