Open Hardware GPS Tracker Works On Your Terms

November 28, 2020 by Tom Nardi 19 Comments

These days, there’s plenty of options if you want to get a GPS tracker for your vehicle. Unfortunately, they come with the sort of baggage that’s becoming increasingly common with consumer tech: subscription fees, third-party snooping, and a sneaking suspicion that you’re more commodity than customer. So [Viktor Takacs] decided to take things into his own hands and create an open GPS tracker designed for privacy minded hackers.

As [Viktor] didn’t want to reinvent the wheel, his design leverages several off-the-shelf modules. The core of the tracker is the ESP32, which gives him plenty of computational power while still keeping energy consumption within reasonable levels. There’s also a NEO-6M GPS receiver which works at the same 3.3 V level as the ESP32, allowing the microcontroller to read the NMEA sentences without a level shifter. He decided to go with the low-cost SIM800L GSM modem, but as it only works on 2G networks, provisions have been made in the board design to swap it out for a more modern module should you desire.

For the code to glue it all together, [Viktor] pulled in nearly a dozen open source libraries to create a feature-complete firmware that uses MQTT to create a database of location data on his personal server. From there the data is plugged into Home Assistant and visualized with Grafana. This is enough to deliver core functionality, but he says that more custom software components as well as a deep-dive into the security implications of the system is coming in the near future.

We’ve seen custom built GPS trackers before, as generally speaking, it doesn’t take a whole lot to spin up your own solution. But we think the polish that [Viktor] has put on this project takes it to the next level, and ranks it up there among some of the most impressive bespoke tracking solutions we’ve seen over the years.

Old Rotary Phone Gets Called Into Action

February 4, 2020 by Kristina Panos 19 Comments

The more glass we punch with our fingertips, the more we miss fun physical interfaces like the rotary phone. Sure, they took forever to dial, and you did not want to be one of those kids stuck with one during the transition to DTMF, especially if you were trying to be the 9th caller to a radio station, but the solidly electromechanical experience of it all was just cool, okay? The sound and the heft made them seem so adult.

[Tal O] gets it. He’s all but finished bringing this old girl into the 21st century without giving anything away on her surface. Inside are some things you’d expect, like a SIM800 GSM module for the telephony part, and an ESP32 to count the pulses from the dialer and communicate between it and the GSM module. But it also has a few things we haven’t seen before. The entire journey is outlined in a five-part video series, and we’ve got part one dialed in for you after the break.

Although [Tal] got the ringer working to prove it could be done, he didn’t want to have a separate 12V circuit just to run the bells. Also, the bells and their electromagnets take up a lot of space, so he compromised with an mp3 of a rotary ringer. [Tal] also wanted a way to have dialed-number feedback without cutting up the phone to add a screen, so he found a text-to-speech library and made the phone speak each number aloud as soon as it’s dialed. It uses the same internal speaker as the ringer, but we think it would be neat if the feedback came through the handset speaker.

If [Tal] is looking for another modern convenience to add to this phone, how about speed dial?

Continue reading “Old Rotary Phone Gets Called Into Action” →

A Simple, DIY GPS Tracker

May 19, 2017 by Brian Benchoff 41 Comments

Today, there are dozens of off-the-shelf solutions for a GPS tracking device. Most of them use GSM, some of them use satellites, and all of them are astonishingly inexpensive. If you want to track a car, dog, or your luggage, you’ve never had more options.

[Emilio] wanted to track his own car, and the original solution for this was a smartphone. This smartphone was also a good choice, as it’s a programmable GPS device connected to a cell network, but there had to be a simpler solution. It came in the form of an eight euro GPS module and a three euro GSM module (Google Translatrix right here). The rest of the hardware is an ATMega48V [Emilio] had sitting around and a 2500 mAh lithium cell. It’s a cellular tracker make out of eleven euro’s worth of hardware and some junk in a drawer.

There are only a few caveats to this hardware. First, the ATmega48V only has one UART. This is connected to the GPS module at 9600, 8N1. The connection to the GSM M-590 module is only 2400 bps, and slow enough for a bitbanged UART. This hardware is soldered to a piece of perfboard, thus ending the hardware part of this build.

The software is a little more complex, but not by very much. The GPS part of the firmware records the current latitude and longitude. If the GSM module receives a call, it replies with an SMS of the current GPS coordinates and a few GPS coordinates seen earlier. Of course, a pre-paid SIM is required for this build, but those are cheap enough.

Not even ten years ago, a simple, DIY GPS tracker would have cost a small fortune. Now that we have cheap GPS modules, GSM modules, and more magical electronics from the East, builds like this are easy and cheap. What a magical time to be alive.

Hack Anything Into A Phone

September 29, 2015 by Al Williams 21 Comments

If you’ve spent much time tinkering with electronics, you’ve probably heard of [Seeedstudio] from their development boards, tools, and their PCB fabrication service. Their latest Kickstarter venture is the RePhone, an open source and modular cell phone that will allow hackers to put together a phone by blending GSM modules, batteries, screens, and other stock units, including an Arduino-based processing core, GPS, NFC, and other building blocks.

The funding campaign has already exceeded its goal and delivery is scheduled for next year with a basic kit weighing in at a projected $59, according to [Seeed]. Presumably, the core phone module will have regulatory acceptance, but the other ancillary modules won’t require as rigorous testing and certification.

What would you do with an inexpensive, embeddable cell phone? The modules are tiny, so you could implant them in lots of places. Some of [Seeed’s] more interesting ideas include building a phone into a walking stick, a dog collar, or a kite (although we were thinking quadcopters).

Of course, we’ve seen GSM and cell phone shields for Arduino before. Difficult to imagine sticking those in a dog collar, though, unless you have a fairly large dog. If you are a fan of 1960’s TV, it is easy to imagine a better shoe phone or a working Star Trek communicator.

Continue reading “Hack Anything Into A Phone” →

Don’t Steal This Laptop

September 22, 2015 by Will Sweatman 74 Comments

As laptops have become smaller and easy to carry around, they have also picked up the most unfortunate property of being easy to steal. We’ve read the stories of how some victims are able to track them down via webcam still images of the thief. [Mastro Gippo] decided to take it one step further and add a remotely operated hardware self destruct to his laptop. The idea is if the laptop becomes unrecoverable, it will become useless and any sensitive data will be destroyed without harming the area around it.

It’s somewhat inception like, as it’s a hack within a hack. It’s based on the Crunchtrack, a CAN bus reverse engineering tool equipped with GPS and a SIM800 GSM module, which was also developed by [Mastro Gippo]. The idea is to tuck the small board somewhere in the laptop and wire it up between the battery and some sensitive parts. Send a single SMS text and ‘poof’, bye-bye laptop.

He wrote all the code in less the 24 hours for the BattleHack Hackathon. He decided to spice up the act with some firecrackers and a detonator, which made his team the crowd favorite and earned a victory.

Continue reading “Don’t Steal This Laptop” →

The 2G Raspberry Pi Smartphone

April 4, 2015 by Brian Benchoff 32 Comments

For [Tyler]’s entry to the Hackaday Prize, he’s making something that just a few years ago would be unheard of in a homebrew build. He’s making a DIY smartphone. Yes, with cheap single-board Linux computers, GSM modules, and SPI touchscreen displays, it’s possible to build your own smartphone.

Inside [Tyler]’s DIY smartphone is a Raspberry Pi Model A, a 3.5 inch touchscreen PiTFT with 480×320 resolution, and an Adafruit FONA module The connections are simple enough; the TFT is connected over SPI, and the GSM module over serial. The entire device is powered by a 1200mAh LiIon battery, charged with a powerboost board, runs an operating system written in Python capable of making calls, sending texts, and takes pictures with a Pi camera.

This is not what you would normally call a smartphone. The FONA module is 2G only, meaning you’re limited to 2G speeds and 2G networks. AT&T will be shutting down 2G networks in a little bit, although T-Mobile will be keeping them up for anyone who still has an old Nokia Brick.

That said, [Tyler]’s phone is still exactly what you want in a minimal phone: it just makes calls and receives texts, it has a camera, and unlike the Nokia, you can take it apart and repair it easily. Not that you ever had to do that with a Nokia…

The Rotary Cell Phone

June 16, 2014 by Brian Benchoff 30 Comments

It’s happened. It’s finally happened. In a move that has hipsters donning their good flannel and breaking out that case of Genesee they were saving for a special occasion, the rotary cell phone is now a reality.

[Jaromir] created this astonishingly retro future device as an entry for the NXP LPC810 challenge, a contest to do the most with an ARM Cortex M0+ microcontroller in an 8-pin package. Having only six I/O pins for controlling a GSM module, display a few buttons, and the fancy rotary dial meant [Jaromir] needed to expand his I/O some way. He chose a shift register to handle the buttons and display in a somewhat impressive demonstration of using a shift register as both an input and output expander at the same time.

From the videos [Jaromir] uploaded, the rotary cell phone isn’t ready for Think Geek to do a production run quite yet. He needs to enter the PIN for the SIM card, AT commands for the GSM module, and is, of course, a horrible method of user input for the younglings who have only seen rotary phones in old movies. That being said, it’s a rotary cell phone running on an 8-pin microcontroller. What more do you want?

Videos of this awesome this truly awesome phone in action below. If you’d like to build your own – and why wouldn’t you – all the files are available on [Jaromir]’s git

Continue reading “The Rotary Cell Phone” →