GPS Pet Trackers... I guess I'm dumb... - Page 1
Forum section: electronics / general

author: GlennSprigg
author_rank: Super Contributor
timestamp: October 26, 2018, 01:36:01 pm
content: They proliferate the Internet now. My description under my Name says..."Medically retired Tech. Old School / Re-learning !", but I think I'm going backwardsMOST, (and rightly so?), utilize a SIM card, and work virtually like a Mobile Phone. The built-in GPSsystem communicates via the Cellular Network, to interact with an IOS/Android App on your SmartPhone.However, there are at least 2 problems!...(1) That ALL the cheap ones ($30-$50 range, so I found out), ONLY work with the old '2G' Networks,which are now defunct here in Australia!!. (I realized that, but read on).(2) They say in their (often cryptic) Specs, that they also work via WIFI, which is a misnomerNow, i really DO understand about what happens via a Sim Card, and how it will work no matter HOWfar away the GPS Unit/Car/Dog/Cat is. Be-it a hundred Metres or a hundred Kilometres!...However, that is not what I need !!! I simply want to know where my CATS are in the evening whenthey haven't come home yet, or be able to see where they HAVE been, when they DO get home !(As in plug it in later, and look at the History, even, when back home?)And this is only about relatively small movements, like within so many houses in any direction from home.When the suppliers spoke about 'WIFI' functionality/availability, I totally misunderstood them!THEY were talking about a GPS system failure, where it would 'supposedly' fall back to approximatingthe distance, from a WIFI Base-StationHuhhh???The 'Device' that I purchased, showed a Fault on power-up, without a Sim Card. (OK). I tried an OLD2G Sim Card, PURELY to get it past the Power-Up condition, which it did. But still no comms from App.,although the 'App' was set up with the correct I.D. codes for the device.WHAT I EXPECTED, was that this device could obtain GPS data, and be ABLE to send that Datavia WIFI also!, if within range ? (a few houses, I know..) instead of via a large Cellular Network.I don't understand why such a 'Device' can not SEND such 'data' over WIFI to a 'SmartPhone'

author: JVR
author_rank: Regular Contributor
timestamp: October 26, 2018, 02:25:35 pm
content: Strip and post pics.I'm willing to bet it does not have a WiFi radio inside. WiFi is hard to do cheap, as you need to connect to a network somehow.

author: Brumby
author_rank: Unknown
timestamp: October 28, 2018, 01:45:59 am
content: I'm wondering if they actually mean the "Assisted GPS" function - AGPS. This is where the cell towers in the vicinity are used to take a guess as to the location of the receiver with respect to them. The location of the cell towers are known and I imagine a computation could be made based on relative signal strengths.Interestingly, there was a study that was looking to track the movement of domestic cats I came across sometime in the last year or two where you could put in some details about your pet and, if selected, they would send you out a GPS tracking collar. I filled in the details for the feline here, but didn't make the cut.Edit: Found it...https://www.environment.nsw.gov.au/research-and-publications/your-research/citizen-science/animal-and-plant-surveys/cat-tracker-australia

author: GlennSprigg
author_rank: Super Contributor
timestamp: November 05, 2018, 12:39:12 pm
content: Quote from: Brumby on October 28, 2018, 01:45:59 amThanks for your reply mate. I've been off-line due to ill health sorry...I will look into those points, and check out that link !!As a side-note for the time being... I've realized/remembered that 'WIFI' doesn't workbetweenend-of-line devices like SmartPhones (), unless you have ROOT, and TETHERING set up !?I remember doing that ages ago with the Missus's phone, (pre NBN we have now) to use HER data-plan !!Obviously you like cats too !!. Our naughty buggers like 'Roamin-in-the-Gloamin' before being locked in !

author: cdev
author_rank: Super Contributor
timestamp: November 07, 2018, 01:33:36 am
content: You can make a GPS logger for very little, using a NavSpark, although I cant think of a good case that would fit on a cat and be safe from them getting caught by some branch. Remember a logger does not tell you where they are at that moment. You can only download the info when they return.I have not built this specific project, and I am not sure if their cheapest GPS can be used in it. The article implies it can't, but I would not be surprised if it could be. The generic navspark gps is around $25 each. The mini in quantity is only around $7http://www.navspark.com.tw/project-1This GPS can do both the GPS and the logging in one. And its very accurate. You will still need the other parts, a (micro or regular)SD card and holder, some means of transferring data via the UART (a plug with four connectors) also most people here already have a USB UART dongle. You'll need a ufl compatible GPS antenna with pigtail, (you could use a passive antenna and ground plane but if you use one remember the input needs ESD protection, which is the solder blob in the middle, protect it from esd at the antenna input, (remember cat fur generates lots of ESD when rubbed on plastic.) and a rechargeablebattery and some perfboard or veroboard for the PCB. I would also recommend using a socket so you can replace the GPS if your cat is the type that likes water. I think the best socket would be a low profile wide DIP socket, or you could use two bits of header, but then it will be a bit bigger, that adds a bit of height, so approximately, with a battery, depending mostly on the antenna used and the battery size, the entire GPS tracker is going to be maybe a bit smaller in height but also likely a bit deeper than a pack of cards. Plus your case.