Episode: 143
Title: HPR0143: Open GPS Tracker
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr0143/hpr0143.mp3
Transcribed: 2025-10-07 12:24:16

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Alright, at the end of your turn, I'm going to tap two swamps, two planes, a mountain
of forest and two islands, and I'm going to put into play Hacker Public Radio.
It is a legendary creature with flying, trample, and vigilance.
Hacker Public Radio has the power and toughness equal to the total number of listeners in the audience.
Also, I can pay one colorless and tap Hacker Public Radio for the ability to rock your socks.
Hey, and welcome. I am more gallon, the low-tech mystic. And you?
Well, you, my friends, would be listening to another fine edition of Hacker Public Radio.
And today, on Hacker Public Radio, we're going to be talking, or we, I guess, mostly I, since it's me and the microphone tonight.
And, well, hey, since it's here, it's the microphone, me, and a tasty beverage.
So, shall remain anonymous for its own sake.
But regardless, wow, man, like a second in and we're already off.
Do I even might keep going with this? Yes, we are.
Alright, this is just going to be a very informal episode, clearly.
But, so sit back, relax. I'm going to smoke me some cigarettes, and I'm going to drink me some tasty beverages.
And we're going to talk about some open source hardware.
Because recently, I, let's say about a month and a half ago, I graduated from college.
Got me a little associates degree in mechanical engineering technology.
And the program I went into with mechanical engineering, technology, and robotics.
I really wish the degree to say robotics.
Because I really like robotics and that kind of stuff.
I really enjoyed the entire program, covered PLC's, digital circuits.
But blah, blah, blah.
We're already rambling again.
And like, 50 seconds in.
This is going to be a rough one, guys.
Yeah, everyone just clicked off the audio player.
Sorry.
Yeah, enigma.
Enigma's just going to take me off this fucking list.
He said, man, edit your fucking shows.
Jebus.
Oh, I shouldn't say Jebus.
Now I'm going to have to redo this whole thing.
You know what?
Fuck it.
I'm going to leave it in, because maybe this is funny.
And maybe it's annoying.
Sorry if it's annoying.
All right.
But basically, I'm really interested in open source hardware.
Because I really enjoy hardware.
I started out as kind of a computer guy.
And as I progressed through my computer knowledge, learning basically thanks to the community.
So everybody listening.
Thank you.
Because you're the community.
And if it weren't for you, I would have never got involved in school and never actually made
something on myself as opposed to just being the rambling crazy guy.
Now I'm the racing.
What an under crazy rambling guy with a degree.
So yeah.
And a bunch of student loans.
But that's that's for another episode.
But really as I learned more about computers and what was going on with technology.
And it came more and more interested about the whole hacker scene and stuff like that.
I really found myself more drawn to the hardware side of things.
What's these?
What's inside these little magic boxes that's making, you know, the magic happen basically.
And, you know, because that's the thing, you know, the better hardware, you can always do more things.
Hardware comes locked down.
You know, I remember being amazed by finding out that you can, you know, change the firmware on some things.
And then all of a sudden, you know, your hardware does completely new things.
That concept blew my mind in the early days.
So continuing forward, basically I'm really interested in doing it yourself hardware.
DIY technology websites like Make and Structables and all kinds of just everybody working on their own projects really gets me excited.
The same thing with the Arduino microcontroller.
That's something that I've really been working on and probably should do a nice little episode about somebody I'm spacing right now has already done an episode about microcontrollers just kind of giving a little bit of what's going on.
And it was a fairly good episode and helped me out just kind of piecing together some more about microcontrollers and stuff at the time.
So, but today instead of just talking about microcontrollers and all that, we're going to talk about something as you can do with microcontrollers that's really cool and fairly inexpensive and relatively easy to do.
And whenever five minutes into the show, we hit to the topic of the open GPS tracker and the open GPS tracker is a really, really cool device.
And this is stopping right here.
This is never going to hit the air.
Yeah, forget it.
We're going to keep going.
Okay, so the opening GPS tracker official website is www.opengps tracker.org.
We'll have links in the show notes for all the websites.
So I'm going to talk about it in this episode.
But basically what's going on with the open GPS tracker and I'll give a little description straight from the website.
The open GPS tracker is a small device which plugs into a $20 prepaid mobile phone to make a GPS tracker.
The tracker responds to text message commands, text motion and sends you its exact position ready for Google Maps or your mapping software.
The tracker firmware is open source and user customizable.
So basically what's going on here is you go out and you buy a specific phone which is actually required.
It is a specific phone, not just a random prepaid cell phone at this time.
It's an AT&T Go phone.
It is the Motorola C168i.
It's basically a small at the form.
It looks like a little candy bar kind of cell phone.
It's not a clamshell or anything but it's available at most big box stores.
So anywhere that you would go and be able to buy a prepaid cell phone you should be able to see the Motorola C168i.
And this is the particular cell phone that you need because the developer has discovered that the headphone jack which also you know pulls out the audio
and yes you would use for your headset you know hands free while you're talking on your prepaid cell phone also doubles as the data port on this particular prepaid cell phone.
And it's also open which means that the developer is able to quote unquote pull the phone which means he's able to send it commands that's what Paul means.
So he sends commands to the cell phone and when he pulls the cell phone it makes a cell phone respond with whatever information that he's asked.
And this way he's able to in his case he uses an AVR microcontroller.
The particular microcontroller is the excuse me.
It's an anti-LVR microcontroller.
It's the AT tiny 84 20PU.
But it does not stink.
But this particular microcontroller is what they're using to interface with the phone.
And on the other side of that is the actual GPS module.
It is a...
I don't know how you say that little acronym.
It's the S-I-R-F star 3.
S-I-R-F star 3.
S-I-R-F star 3?
I don't know.
Tasted beverages.
I don't know.
But anyway the S-I-R-F star 3 is one of the nicer GPS modules and it's capable of getting a fixed signal inside of a lot of buildings and other locations.
Obviously if you're inside a concrete parking garage or the steel building you're probably not going to get to get the reception.
But basically what's going on is you're able to, from your cell phone, send a text message to the prepaid cell phone which is then based on the text command that you send it.
It's going to pull the GPS for information and then reply back to your original phone with the prepaid phone's location and speed if it's moving and stuff like that.
So some of the initial ideas that they give from the open GPS tracker website is the concepts of being able to track your car if it's stolen.
So if you walk out into the parking lot and somebody stole your car, if you got the GPS tracker in your car all you really need to do is send a text message to that prepaid cell phone and it's going to text you back with the information of where it's at and also if it's moving.
So you can wait until the vehicle stops moving and then have it send you its geospatial location which is ready for Google Maps.
You pop that into Google Maps. You call the cops and you say, yeah, some dudes just stole my car and they're at Yadi Yadi Yadi Street.
Yeah, go take them to jail or if you're a little more Batman style, you go do it yourself because you know if you can make GPS trackers and track evil doers, well you're one step closer to like Spider-Man or Batman, some kind of superhero.
But other than the vigilante side, I don't know how do we get into vigilante. I'm just really stoked about the new Batman movie. But before we go into that whole tasty beverage, yeah.
And so another potential application that they're bringing forth, this ability to say whether you are a company like say a small company or you are a parent.
So in this particular application, we'll say you are a parent and you are interested to know your vehicle's information because you just let your teenage child borrow the family car to go out because they recently got their license.
So you've given them a night out on the town, a night out on the town to drink some more tasty beverage.
And so you've given them a few restrictions to enjoy their night out on the town. One being that since you're a novice driver, please don't be driving fast and two, don't get out on the interstate because you know we've not been out on the interstate yet so we don't want you out there.
So conveniently you can set a quote unquote speed limit in the GPS tracker so that any time that the GPS tracker exceeds a certain speed limit, it's sending you a text message to whatever cell phone you set up.
Obviously it's going to be your main cell phone or it can it to consent to an email address. So you have the option of text or email responses.
So in the email option, you can send a text message from any cell phone and it would always go to the same email account or with the text message option.
Oh, good one with the text message option. It would obviously always send to what's not obvious that's why I'm stating it.
It would respond to the same text message. So that's one of the options that you set it up with is the responder cell phone.
So you can send text messages from any phone but it's only going to reply to a set cell phone number or a set email address which you can change it anytime assuming that you know the password and the number of the prepaid cell phone.
So but assuming you know teenage child is out and they decide to get on the interstate.
The size you know what mom and dad said and you know all of a sudden you get a text message saying or an email saying hey, John Q teenager is speeding
and they're actually going 70 miles an hour and here is the GPS location which you copy and paste into Google Maps.
And wow, it looks like they're on the interstate so you can give a nice cell phone call to John Q teenager and which you kindly let them know that they need you to return to their official home residents so that they can have their head bashed in or whatever proper response is.
I don't know things I'm childless, I don't know the proper response.
So your mileage may vary but so those are some of the basic potential applications from the open GPS tracker website.
So basically if you are interested in constructing this project the most expensive thing out of the whole shebang shebang shebang shebang is the GPS module which is $61.50 which I ordered from Malzer electronics.
I ordered actually all the parts for the open GPS tracker from Malzer and after shipping and handling it ran me about $94 but except for the GPS module I got doubles of all the components or more than double of all the components.
So basically let's see other than GPS module you have the micro controller programmer which is about $40 which I did not order from Malzer and I'll jump back to that here in a minute.
But other than that the most expensive component is the $20 prepaid cell phone.
Everything else is under a dollar except for the actual micro controller which is $2.90 and what is that?
It looks like the headphone jack for the phone is above a dollar and a header pin so but as I touched on before in order to actually it's actually very easy to solder together this project.
So basically if you have the basic ability to solder through whole components or not talking about tiny tiny tiny surface mount stuff or you know something you need ninja artistry soldering skills to be able to even think about attempting no no no no no my friends this is something that you go down to radio shack or as we like to call it rat shack you go down to rat shack.
You get your little proto board which is a little brown board with a bunch of holes in it and then you get all these components that you ordered from Malzer or whatever did you key.
Geez now I'm spacing on their online electronics places but there's plenty of them out there so wherever you decide to order your components from you get these easily available components from whoever you want which cost me $94 after shipping and handling and you put all this together on a proto board and one cool thing about having at least doubles of all your particular components.
This is that a if you miss up no big deal but be a plan on making a breadboard version and then actual proto board version so the breadboard version I'm actually going to be able to try to advance upon the idea maybe even try swapping in our do we know chip for the regular micro controller to emulate some of the same text commands or get the same.
Functionality that's going on in the AVR was it AT yeah AT tiny 84 dash 20 p.u which does not stink yeah but yeah so basically with the proto board I could play around with different power supplies stuff like that one thing that I'm interested in seeing is if we couldn't throw in say like.
Maybe like an 11 or a 9 volt solar panel with a window okay I take that back you need an 11 volt solar panel and had that hooked up to a 9 volt battery which is a rechargeable battery and then assuming you had sunny days and stuff like that you could use that to power the micro controller or.
Such a device so you still have to worry about power in the phone so you might actually in reality in reality need to 11 volt solar panels but yeah with your two 11 volt solar panels or a 22 volt solar panel I don't know if these these particular voltages and solar panels even exist but you can find a way to.
Work it out whatever I'm just kind of rolling off the top of my head here guys but basically if you had the ability to have you know at least 22 volts you could use a radio later over whatever to to get your voltage but.
You could be able to kind of basically slow this out into the wild or something like that and then 11 volts solar panel even to oval is not going to be that large in size.
It's probably going to be maybe a little bit bigger than the actual phone itself maybe a little bit you know longer and a little bit wider but obviously not thicker.
So it's probably something that you could throw on the outside of the case or something like that but a one thing that tweaks my interest heavily is other applications that you could use with the open GPS tracker.
And the thing that gets me really excited about the project is it's not the fact that I could use the open GPS tracker to track my stolen car or track my teenage but it's all the other applications that like just start rolling through my brain about what you could do with the open GPS tracker.
And like for me one of the first things that kind of pop into my head about the open GPS tracker is you know this would be a fantastic application for you know little robots.
Okay so one of the things that I'm interested in tasty beverage and robots is the idea of making outside robots.
To get a little personal one thing that my mother and I that was kind of a bonding thing for us myself and my mother really don't get along particularly well but one of the things that we really bond and do grow close doing together is gardening.
And my mother is a avid gardener she has flowers and all kinds of good stuff that she likes to do and it's something that we get out together and there's just there's no hate involved we just have a good time and everything kind of just drops while the gardening is going.
And one thing that I've always thought would be really cool is to have the ability to have a robot that assists you in your watering process because like say to jump back to a commercial robotic application like the Roomba.
The Roomba itself kind of randomly moves around and back into your carpet.
Excuse me but the Roomba itself is not going to be able to do all of your vacuuming work.
It's meant as a small tool that helps you out to the week so you just have to do less vacuuming not that you have to do zero vacuuming but it decreases the overall amount of vacuuming that you need to do.
Same kind of idea with the little robot that's going to move you around outside and I think it'd be really cool to have a little robot that can navigate maybe using GPS combination of vision sensors and RFID to use navigation to know where it's at to know which plant is sitting in front of and to be able to give it some water.
You could throw in really easy some soil sensors which are cheap and easy to make which would monitor the pH of the soil and basically let you know how this particular plant needs water or this particular plant is a okay and don't give it any water.
So you could have a little little tank of water that you know the robot could go back to kind of like a pumping station or something and get filled up with water and then mosey around and give a little bit of water to the plants that needed water the most.
Okay and you know this clearly isn't going to do all the watering of plants for you but it would allow it would assist you in watering the plants and allow you to not necessarily worry about watering the plants every night because one thing that I definitely learned as you continue to climb the ladder you know so to speak and you know as you get.
You gain more skills and get different jobs and stuff like that you know you really find yourself competing for personal time and when you do have personal time it's very valuable to you and so what you spend doing you know in your free time is crucial to you so you don't want to waste all your free time doing meaningless tasks and so if the small amount of free time that you have being a professional individual.
You know you're having to water your obscene amount of plants that back in the day you know wasn't such a big task but now you have less and less free time and you have you know the same amount of plants that you can't get around to so at least this way the little robot could go around and save the ones that needed water the most and thus keep your plants from dying.
So that one day a week where you have excess free time and you can actually enjoy watering your plants and not feel guilty for killing your plants because you didn't have the time to do the basic watering through the week and you know using this process because you know most of the plants and stuff are outside you know you could hopefully have some solar panels on the little robot that's going to be charging the robot.
So, granted it's not going to be able to be mobile 24-7 but it's not going to be something that I'm going to have to be constantly worried about let's say okay I'll set up a you know a boundary parameter based on a combination of RFID and other sensors.
They'll basically let it know this is the boundary area that it works inside of and set different locational spots of plants and stuff like that inside that area.
And then from there the robot would know where to navigate as far as what plants for what based on different sensor responses and when to recharge or refill his little water tank.
Because that's one thing that you're going to keep in mind is that water weighs a certain amount of weight and in order to transport that weight you're going to need a motor that's capable of carrying X amount of weight which is going to require X amount of power so you're going to need a power source which is capable of providing that and you're going to need the ability to charge that power source.
And with it being a little John Q random robot it just rolls around in the backyard watering the plants you know I see a bunch of solar panels and stuff like that kind of branching out from it that are going to recharge the robot so it's not constantly active but as it drains its power source you know it sits in the sun and collects its power.
And you can even add in some other small features say like not necessarily AI per se but the ability to with some photo detectors some photo cell sensors stuff like that that basically the variable resistors that change their amount of resistance based on the amount of light that hits it.
So you could hook up some photo cells to the art what are to whatever microcontroller that you're using as part of the brains of the robot which I would use and it probably would be an Arduino sings how I'm on the Arduino quit.
The Arduino kick at the moment wow tasty beverages make Arduino really hard to say and at this moment we're going to take a tasty beverage break because we're 20 something minutes almost 30.
I think we need to cigarette so but basically you could have a a sunlight detector for lack of a better word you know let's break it down photo cell photo cell detector photo resistor or using these fancy words.
Okay sunlight detector and basically you're going to have a little photo cell like you know it could look you know it could even look like a little LED it become in different shapes and sizes that's the neat thing about electronics and components they come in all kinds of different shapes sizes you can get all you can really be able to do your desire.
But you can have the microcontroller register the highest amounts of sunlight based on whatever area the little robot was moving around in and you can also set up a little call in the programming so that this monitoring the battery power.
Good to end the battery power of the robot so when I hit 20% or 10% or whatever the critical level is I'll know that whatever that critical level is I'll have enough battery power to wheel the little robot out to the brightest part of the yard.
And thus the robot can sit there and recharge and once I have you know the robot has recharge to and accept acceptable level of power it then begins the water and process again and therefore you know you've got a little robot that just kind of is able to maintain on its own and have rumbled on a long time about this but this is just kind of one very small application of how you could apply the GPS tracker.
To say like a robotics application and I went in depth in it because the open GPS tracker allows you a cheap way to interface into whatever system you want to design it to interface into and to give you geospatial location time location you know movement rate whether it be miles per hours kilometers per hour altitude.
So you've got a lot of different various applications with a $20 prepaid cell phone and a $60 GPS module that you know you really all of a sudden have a whole lot of power in the do it yourself kind of arena.
A lot of these modules for doing GPS or wireless communication or even GSM which would be your kind of cell phone development boards are very expensive and can you know even go into hundreds of dollars.
You know these things don't come under three figures you know you're paying $100 or more you know usually more for these kind of things so to be able to piece this together for a lot cheaper and free code is something that's very cool to me and so very big and very very serious tip of the hat to the people at open GPS tracker.
It's a lot of work because you guys are doing a bang up job and there's a whole bunch of applications that I would like to try out with this.
So let's see about 30 something minutes into this hacker public radio.
How's everybody doing out there everybody doing all right yeah you're still listening to me as the same okay so let's go a little bit more into the open GPS tracker.
The open GPS tracker itself has a lot of functionality built in the code that's running on the microcontroller or that you flash onto the microcontroller.
And here whoa whoa whoa let me take a step and break it down because if you're still listening then obviously you're interested and I'm sorry that I'm not taking it more serious.
But hey it's Friday hopefully sometime and but it whatever we're being relaxed and obviously because I'm sitting outside and you can probably hear all the bugs and the road noise and anyway.
So basically when I say we're going to flash the chip basically we're going to use that microcontroller programmer which I never bounce back to which is a good time to bounce back to that.
But you're going to use that microcontroller programmer to load the code that you downloaded from the open GPS tracker website onto that microcontroller.
And from there you've got a lot of different options and stuff that you can do with the GPS tracker.
And it's very slick they have they've set up a lot of different options they have a couple different tracking modes that are that are more friendly or less friendly with power consumption.
And they also have modes to detect when the GPS module has lost reception say you go into parking garage or a tunnel or just basically any kind of area where you don't get GPS reception the receiver will shut off.
And it will power down into a low power state until the point where you know it the GPS begins to receive information again from satellites then it'll power on the cell phone since you text information and that you're not burning up battery life while you have no GPS reception.
So well ran the line but you download all this firmware onto the microcontroller with the bootloader which they call flashing a chip or flashing the wrong because the microcontroller is nice essentially a wrong.
So I guess it's okay to say you're flashing the wrong but you're flashing the chip regardless.
And on the open GPS tracker website the open GPS tracker dot ORG or it's WWW dot open GPS tracker dot ORG if I haven't said enough in this episode you can make a drinking game out of this episode.
You just take a drink every time Morgan says when GPS tracker did you would make it past it first like 20 minutes.
But basically on their website that the microcontroller the programmer that they recommend you buy is the AVR ISP 2 USB AVR programmer which is kind of the standard AVR programmer and it runs they have the price quoted at 35 91 which is pretty close to right I usually say about 40 bucks.
But a lady ought all lady Ada if you're familiar with the make magazine or the Arduino chip you're probably familiar with lady Ada lady Ada has a nice AVR programmer which is very inexpensive it's about half the price.
She calls it the USB tiny ISP and it's an AVR programmer and SPI interface.
The AVR programmer that's 40 dollars only has a six pin it has the six pin standard AVR programming header whereas the cheaper 22 dollar programmer from lady Ada has the six pin standard AVR programming header.
Which what does that mean? That means that you have the ability to flash or load code onto a wider range in spectrum of microcontroller chips.
The USB tiny ISP is compatible with most of the AVR type software like AVR dude and AVR studio it's going to work with windows linux and macOS X.
It's a cheap programmer it's nice for a backup programmer and stuff like that so I decided to go this route and save myself a little bit of money.
And also have that's going to be the ability to flash boot you know the bootloader of the Arduino onto other 80 mega 168s so I'm excited about that as well and just I'm excited about the Arduino chips in general.
But definitely check out the open GPS tracker website there's a lot of cool applications that you can do and if you've got a little bit of money laying around and you're interested in electronics I highly highly suggest you know you check this out.
It's really something that's going to be easier to do easy to put together for a simple project and you're really going to get a big bang for your buck.
This is you know something that you can put together and you're going to get more than a blinky LED or you know some kind of simple project you're actually going to get something that has a large range of functionality.
And it's going to get you very excited about the world of electronics which you should be because you know what buddy electronics rock like yeah and tasty beverages.
So thanks for listening this horrible episode of hacker public radio hopefully I've managed to get you interested into hacker public.
Hopefully I managed to entertain you on some level and additionally hopefully I've managed to interest you into the open GPS tracker or maybe open source hardware or maybe electronics in general.
One thing that I'm planning on doing is if you're still listening at this point you're interested so I plan on making the open GPS tracker myself as I've already mentioned I have all the components for the open GPS tracker sitting at my house ready to go minus the actual programmer which is in the mail and on its way.
So one thing I'm planning to do is literally document my entire build process so I'm going to take pictures and videotape all the work that I do as far as putting together the open GPS tracker.
I'm going to put it together on the breadboard first get you know verified that it all works the way it should and then I'm going to put it together on a proto board and I plan on documenting all this.
So if you're wondering what I'm rambling on about I have a website I have a blog is at infodemon.com and it's it's much less rambling perhaps a better grammar than in this episode but you can find it at i-n-f-o-d-e-a-m-o-n.com.
That's infodemon.com or infodemon.com however you prefer to pronounce it because that's how I wrote.
We love freedom here yay freedom but at my blog I plan on posting all the work that I do with the open GPS tracker.
I'm going to upload video to youtube have it available from my website download and a better higher quality and basically will you get involved with this project and attempt to expand upon it.
So hopefully in the future we'll have more episodes of hacker public radio talking about the open GPS tracker and make a little bit more sense and have a little bit more to build upon it because I've actually been able to get it going.
So thanks again for listening guys yeah I hope you guys have a great weekend I hope you have had a fun time listening to me ram one I really enjoyed doing this episode thanks for listening and you know like I say as always remember there's going to be somebody completely different here tomorrow so you guys take it easy.
And we'll see you around.
Thank you for listening to hacker public radio.
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