A Box that can SAVE YOUR LIFE....and get you out of awkward conversations! (GPS/SMS/Call Thingy)

I have to admit it, I do watch Instagram reels from time to time which are basically short video clips about pretty much anything. Most of the time though it is comedy and that is why it gets really funny when a company tries promoting a product through it. Just the other day I saw a clip of a girl who pretended to be kidnapped and who then just pressed her necklace to send out an emergency SMS with GPS information. I thought the clip was really bizarre but I liked the idea of having a device that can send over its GSP location through SMS. So I had a look at the necklaces website which looked promising at first but I quickly noticed that the necklace is just a glorified push button that communicates with a smartphone which then does all the GPS and SMS work. Personally I think the product is still useful but I wanted to create my own version which should come as a small box with a push button that will send out an SMS with GPS information on its own without requiring a smartphone. And as a bonus because my brain thought it would be a good idea, the box should also feature a second mode selectable by a slide switch in which it will simply call a phone number as soon as the button gets pushed so that you can get out of awkward conversations involving pyramid schemes or similar. So let's get started and build this thing! This video is sponsored by Skillshare which is an online learning community for creatives that offers thousands of inspiring classes. Topics include illustration, design, photography, video, freelancing and much more like for example Arduino programming which is the microcontroller system that I will be using for this project. By watching the class Introduction to Arduino: Creating Interactive Projects by Mark Frauenfelder you will be able to pretty much do all the basics yourself when it comes to Arduino programming. So why not give it a shot which actually costs you nothing because Skillshare offers a 1 month free trial to the first 1000 subscribers of mine who click the link in the video description. And now let's get on with my own Arduino project. First off; we obviously need a plan for the hardware in the box which by the way I want to keep as small as possible. So I did a bit of brainstorming and came up with this overview which involves a small 820mAh LiPo battery for portable power along with a suitable TP4056 charge and protect circuit. Then we got an Arduino Pro Mini as the brains of the organization along with a small NEO-6M GPS board with suitable antenna for receiving the GPS position. The last big player was this A6 GSM module which can send and receive SMS and calls. GSM by the way stands for Global System for Mobile Communication and you will need an active SIM card to use it whose provider still needs to cover 2G, GSM or GPRS; whoever you want to call it. But don't think this board was my initial choice because I actually tested 3 different kinds before which either did not respond to my commands, were too big or simply did not recognize my SIM Card. So ultimately I got this board which does its job just fine but more about that in detail later. Last but not least for my plan I got a big tactile push button as an input to start doing things, two slide switches of which one is for power and the other is to select between SMS or call mode and finally a voltage divider with an LED and current limiting resistor whose job it is to convert down the battery voltage for the microcontroller so that at a voltage level of 3.6, it can light up the LED to notify you to charge up the battery. Now I deliberately set the undervoltage limit to 3.6V because it is the minimum voltage the Arduino Pro Mini can receive on its RAW input pin before the voltage drop of the linear voltage converter starts affecting the supply voltage. Also the GPS board works perfectly fine with this varying raw battery voltage of 4.2V down to 3.6V. Only the GSM board initially didn't feel like working with that voltage but I quickly realized that it was using a buck converter to convert its input voltage down. So by simply skipping the converter and directly soldering the power wire to the output capacitor; the board works perfectly fine with the battery voltage. And with all the hardware now explained it was time for me to turn this plan into this schematic which will hopefully work. To find that out I firstly connected all the components to one another in midair through the help of some wire and Wago terminals. Afterwards I was happy to find out that nothing exploded as soon as I powered it all with the battery. And my SIM card also seems to work just fine with the module because I actually made my life easier by firstly inserting the SIM card into a proper phone and removing its SIM lock. But anyway; next I hooked up an FTDI breakout board to the Arduino Pro Mini and was ready to write some code. But before that I have to mention that communicating with the GSM and GPS board happens with serial communication which you should be familiar with because you probably used it before with the serial monitor of the Arduino software. That is why we have to create software serial ports for the GSM and GPS board with a defined baudrate aka communication speed. Now while the GPS module keeps spitting out GPS information we didn't even requested, the GSM module only talks to use when we sends commands which start with AT and then the thing we are interested in. There is actually a whole documentation about all the commands and features you can use with this board. But at first while trying to communicate with it, it didn't feel like responding to me for which the reason was its predefined baud rate of 115200. To change that I simply hooked it up solely to an FTDI board, checked whether it worked which it did, altered the baud to the slower 9600 and then tested it once again in the complete system to find out that this time it worked perfectly. So I played around with different commands of which the most important ones are to call my phone number and hang up which looks like this and as you can see works like a charm and those commands that can send an SMS which as you can see also works just fine. And for the GPS board we can make our life easier by using the TinyGPSPlus library which converts the mess of information we looked at before into simple to use in variable stored values. But wait! Why is there no longitude and latitude information output which is mandatory for a precise GPS position. Well, the reason is that this GPS sensor does not work indoors and I had to get out of my apartment quite a bit in order to get a proper signal which I am obviously censoring here. And with the code basics out of the way it was finally time to write the proper sketch which all in all should be pretty easy to understand. In a nutshell the system waits 10s at the beginning so that the GSM module can connect to the network. Then depending on whether the slide switch selects mode 0 or 1 and the push button got pushed the system either calls your phone number for a couple of seconds before hanging up or the system send over its GPS position as soon it got it through an SMS to your phone. And to test this code I uploaded it to the Arduino board and as you can see the call function worked flawlessly as well as the GPS SMS function once the system was positioned outside. And that means it was time to get rid of this wire mess and start soldering the boards to multiple perfboards that I could stack in order to create the smallest size possible. Honestly speaking though this method of creating a circuit was pretty wild; even for me. And that is also why I was super happy to see that the system still worked fine in its final form. So next I drilled two holes in the top perfboard piece and continued by measuring just a few dimensions of all the parts because in Fusion360 I actually used properly scaled pictures of the most important circuit boards in order to design around them which was a huge time saver. And once I was happy the enclosure for the project, I 3D printed all the parts with my 3D printer, shortened a couple of screws, mounted the charge board inside the enclosure with screws and a bit of hot glue, secured the top perfboard to the lid with screws, attached the remaining perfboards to it and slid everything inside the box to close it all up. And just like that you can make your own Call/GPS SMS box which you only have to power up and push the button to either get out of awkward conversations by maybe calling this contact work or send an emergency SMS with your GPS location. With that being said I hope you enjoyed this video. If so consider supporting me through Patreon so that I can continue producing more videos like this. Don't forget to like, share, subscribe and hit the notification bell. Stay creative and I will see you next time.

Channel: GreatScott!

Views: 265,633

Keywords: box, save, your, life, gps, sms, call, global, position, positioning, system, gsm, mobile, communication, short, message, location, locate, arduino, pro, mini, battery, lipo, charge, protect, tp4056, sim800, a6, ai, thinker, sim, gprs, 2g, 3g, 4g, tutorial, guide, diy, do, it, yourself, make, project, beginner, beginners, necklace, instagram, wiring, electronics, card, lock, receive, send, baudrate, schematic, greatscott, greatscott!, latitude, longitude, microcontroller, uc, button, tactile, slide, switch, perfboard, pcb, circuit, board, phone, smart

Id: 0P4R91hsMf0

Length: 10min 37sec (637 seconds)

Published: Sun Dec 05 2021