Designing GPS system for 12V PS in Heavy Machinery - Page 1
Forum section: electronics / beginners

author: jr
author_rank: Newbie
timestamp: June 30, 2025, 01:57:47 pm
content: Hi everyone/anyone. I have just passed my second year studying Software & Electronic engineering and although I have improved a lot since last year, there is still a strong feeling of sort of imposter syndrome. I decided I wanted to take on a fairly big project over the Summer before I begin work placement and landed on this GPS/Maintenance Tracker for heavy machinery like Diggers, Dumpers, Wood-chippers. Although there is no shortage of these products, in my country atleast they are very expensive or have annoying subscription models. Here is the current schematic I have worked on for the last two weeks, there is a sort of chaotic structure to it all but if I'm being honest, I'm finding it quite hard to figure out how everything works exactly. Any feedback is appreciated ! Thanks, John.

author: Terry Bites
author_rank: Super Contributor
timestamp: June 30, 2025, 04:56:33 pm
content: You're not an imposter, you're just a begininer. There's no club you have to try and join.Re project, assuming it has all the right parts, its down to the functionality and robustness of your code.I kinda doubt anyone is going to validate that for you.I assume you want a career in EE so one big lesson to be learned is to value your time.Real EE skills (not coding...) are very valuable and work experience is invaluable. Find a mentor ASAP.If you didnt do EE as a practical hobby (what have you built?) before you went to college then you'll have lot of catch up to do.Usually people will recruit you based on what you have done not so much on qulaifications.So show off your analog skills, potential empoyers love that. BTW, "Every idiot can count to one" Look it up.Coding aint EE, its just really bloody boring. Leave that stuff to people with poor social skills.

author: jr
author_rank: Newbie
timestamp: June 30, 2025, 05:35:57 pm
content: Hi thanks a lot for responding, that feedback is invaluable to me at the moment. Basically my course in college is a mix of both full stack development, low level programming (Particularly C programming an ATMega328p) and also Electronic Design. So far in my course I haven't actually specialised or anything, it's just been a mix of all of the above. I have 3 projects (done in college, not outside) under my belt such as a smart locker system IoT project, very simple team project for an e-commerce system with MySQL and Java and then just a basic robo-car where we were kind of handed the circuit and just had to solder it and debug hardware and software.So basically, with this project I wanted to create something kind of impressive by myself and create the hardware then software over this Summer period. Social skills are already on the decline so, might aswell jump right into it !

author: coromonadalix
author_rank: Super Contributor
timestamp: June 30, 2025, 06:32:26 pm
content: you have tons of gps modules like u-blox or serial based ones up to 1hz refresh rates, arduino related projects / code snipets or other mcu types tons to choose from the webas a starthttps://www.instructables.com/Displaying-GPS-Location-on-a-LCD-Screen/https://arduinogetstarted.com/tutorials/arduino-gpshttps://www.elithecomputerguy.com/2020/06/arduino-gps-adafruit-ultimate-gps-coordinates-and-speed-display-on-lcd/https://microcontrollerslab.com/interfacing-gps-module-arduino/

author: jwet
author_rank: Frequent Contributor
timestamp: June 30, 2025, 06:34:57 pm
content: Just one comment on your design. I saw at the lower left, a little flag "12v In". The power in vehicles is nominally 12v but its not so simple.Automotive 12v is a messy transient rich environment- this is even more true in heavy equipment and trucks. The reason is that there are lots of high current inductive loads spread out over a kind of rat's nest of wiring harnesses with ground being the vehicle frame. When big loads cycle, the abrupt changes in current cause transients and spikes- these are called load transients and load dumps generally. These transients can be of either polarity and routinely produce spikes of 30 volts of both polarities with unusual transients of over +-100v. Further, the system is all charged by a large alternator and voltage regulator that doesn't react instantly to load and line changes from engine speed, etc. Modern cars are better in this respect and some have some central supression but trucks are still pretty ugly. The act of turning the ignition off on a car produces a lot of spikes as all the energy stored in the loads and the harnesses discharge. You'll see and hear references to ISO-7637, this the main automotive spec. Its pretty technical and not easily available for free but you'll see exerpts and summaries that will get you through.At the very least, include some robust reverse polarity protection, transient protection and HF isolation (inductors) to keep some of the hash out of your system. This is especially important for something with some RF. You only have to do this where power enters your system and then things are pretty normal. Also pay attention when interfacing with a control line that comes out of a switch in the system. Usually a series resistance , reverse protection and a tranzorb plus decoupling is enough. You might want to look at something like the input conditioning for an automotive stereo or other subsystem. There are special linear and switching regulators that can take some of the abuse but the system usually has other discretes upstream as well. Also always include a fuse in your system, Automotive 12v systems can produce amazing currents when shorted.The best sources that I've seen for this kind of design guidance are app notes and good data sheets from the chip companies and a few texts put out by the SAE. Check your engineering library. Maxim has especially good app notes for automotive apps, along with LTC, TI and Infineon.Good luck with your project and your education.

author: jr
author_rank: Newbie
timestamp: June 30, 2025, 06:57:06 pm
content: This is really helpful. A lot of this stuff I haven't even heard of yet and exactly why I wanted to post on a forum, seems as though I have a lot more practice, tests and researching to do !

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: July 01, 2025, 09:52:40 am
content: While not intended to be small and hidden, from a development point of view one of these Raspberry Pi "hats" might prove useful to experiment with:https://thepihut.com/products/sim868-gsm-gprs-gnss-module-for-raspberry-pi-pico?variant=40920300880067&country=GB&currency=GBP&utm_medium=product_sync&utm_source=bing&utm_content=sag_organic&utm_campaign=sag_organic&utm_term=4584757338123435