Handmade GPS Tracker Keeps an Eye on Adventurous Cats

-
A ginger cat, wearing a blue harness with a brass and wooden box on its back

One of the most convenient things about having cats is their independent lifestyle: most are happy to enjoy themselves outside all day, only coming back home when itā€™s time for dinner and a nap. What your cat gets up to during the day remains a mystery, unless you fit it with a GPS collar. When [Sahas Chitlange] went searching for a GPS tracker for his beloved Pumpkin, he found that none were exactly to his liking: too slow, too big, or simply unreliable. This led him to design and build his own, called Find My Cat.

The heart of the device is an A9G GSM/GPS board, based on the RDA8955 system-on-chip. [Sahas] combined this with a data SIM card, a 2600 mAh lithium battery and a charger module to make a completely self-contained GPS tracker capable of transmitting location information in real time. The system is housed in a hand-made brass box designed to be attached to a cat harness, where it sits safely on Pumpkinā€™s back.

A brass box with a GPS tracker inside, along with a wooden lid with antennas embedded insideIt took a bit of experimentation to find a workable antenna setup for this system, because the brass box works as a Faraday cage. [Sahas] therefore made the lid of the enclosure out of wood, and embedded two thin strips of brass within it to make a dipole antenna. Tests in his car confirmed that it got a reliable fix and was able to communicate through the GSM network.

On the software side, The A9G module came with a C/C++ based SDK that [Sahas] found so inconvenient to use that he decided to replace the whole thing with a MicroPython setup. He then programmed it with a simple routine that waits for an MQTT message to start tracking, and otherwise stays in sleep mode. Location data is sent to a Raspberry Pi running Traccar, an open-source GPS tracking server that provides a ready-to-use web interface. Finding Pumpkinā€™s location is now as simple as opening a web browser, navigating to the Piā€™s IP address and looking at the map.

As in many wearables, the largest part of the system is the battery, which in this case provides a good twelve days of usage between recharge sessions. Weā€™d assume that to be plenty, unless Pumpkin is one of those cats that like to go on multi-week expeditions. Limited battery life is a common problem for GPS pet trackers; perhaps switching to an ultra-low-power LoRa-based system might help.



from Blog ā€“ Hackaday https://ift.tt/rsDhJp4

Comments

Post a Comment

Popular posts from this blog

Hackaday Links: May 31, 2020

-
We begin with sad news indeed as we mark the passing of Marcel van Kervinck on Monday. The name might not ring a bell, but his project, the Gigatron TTL computer , certainly will. We did a deep dive on the microprocessor-less computer a while back, and Marcel was a regular at conferences and on the Gigatron forums, supporting users and extending what the computer can do. He was pretty candid about his health issues, and Iā€™ll add that when I approached him a few weeks ago out of the blue about perhaps doing a Hack Chat about Gigatron, he was brutally honest about how little time he had left and that he wouldnā€™t make it that long. I was blown away by the grace and courage he displayed. His co-conspirator Walter Belger will carry on the Gigatron mission, including joining us for a Hack Chat on June 24. In the meantime, this might be a great time to pick up a Gigatron kit before theyā€™re all sold out and get busy soldering all those delicious through-hole TTL chips. May of 2020 is the mo...
Get this oneĀ»

Modern Radio Receiver Architecture: From Regenerative to Direct Conversion

-
Image
Modern radio receivers have a distinct advantage over the common early designs which I covered in my previous article . Most of the receivers you will have worked with over the past couple decades are designs by Edwin Armstrong ; regenerative, superregenerative, or most commonly superheterodyne. These are distinguished by a few fascinating key traits that bring both benefits and drawbacks. Today letā€™s dive into Mr. Armstrongā€™s receivers. Iā€™ll also talk about DC receivers which, despite the name, are not made to listen to batteries. These are receivers you are much more likely to encounter in modern equipment. Regenerative and Superregenerative The regenerative receiver is all about doing more with less. You still see some of these in simple applications like RF remote controls. The idea derives from how an oscillator works. In a simple way of thinking, an oscillator is an amplifier with enough positive feedback that any tiny signal at the right frequency will amplify and then, throu...
Get this oneĀ»

Homebrew 68K Micro-ATX Computer Runs Its Own OS

-
Image
Weā€™re no stranger to home built Motorola 68000 computers here at Hackaday, but more often than not, they tend to be an experiment in retro minimalism. The venerable processor is usually joined by only a handful of components, and thereā€™s an excellent chance theyā€™ll have taken up residence on a piece of perfboard. Then [NotArtyom] sent in his Blitz , and launched the bar into the stratosphere. Make no mistake, the Blitz isnā€™t just some simple demo of classic chips. The open hardware motherboard has onboard floppy, IDE, and PS/2 interfaces, with a trio of 8-bit ISA expansion slots for good measure. The  Motorola 68030 CPU is humming along at 50 MHz, with 4 MB of RAM and 512 KB of ROM along for the ride. Designed to fit the Micro-ATX motherboard standard, you can even mount the Blitz in a contemporary PC case and run it on a standard ATX power supply. An earlier prototype of the Blitz motherboard. As if the hardware wasnā€™t impressive enough, [NotArtyom] went ahead and created hi...
Get this oneĀ»