DIY ESP32 Alarm System Leverages 433 MHz Sensors

April 2, 2020 by Tom Nardi 14 Comments

There’s a huge market for 433 MHz alarm system hardware out there, from PIR motion detectors to door and window sensors. If you want to put them to work, all you need is a receiver, a network-enabled microcontroller, and some code. In his latest video, [Aaron Christophel] shows how easy it can be.

In essence, you connect a common 433 MHz receiver module to an ESP32 or ESP8266 microcontroller, and have it wait until a specific device squawks out. From there, the code on the ESP can fire off using whatever API works for your purposes. In this case [Aaron] is using the Telegram API to send out messages that will pop up with a notification on his phone when a door or window is opened. But you could just as easily use something like MQTT, or if you want to go old-school, have it toggle a relay hooked up to a loud siren.

Even if you aren’t looking to make your own makeshift alarm system, the code and video after the break are a great example to follow if you want to get started with 433 MHz hardware. Specifically, [Aaron] walks the viewer through the process of scanning for new 433 MHz devices and adding their unique IDs to the list the code will listen out for. If you ever wondered how quickly you could get up and running with this stuff, now you’ve got your answer.

In the past we’ve seen the Raspberry Pi fill in as an RF to WiFi gateway for these type of sensors, as well as projects that pulled them all together into a complete home automation system on the cheap.

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Using The Steam Controller With LEGO Motors

April 1, 2020 by Tom Nardi 1 Comment

While Valve’s Steam Controller was ultimately a commercial failure, there’s no denying it’s an interesting piece of hardware. With dual trackpads, a wealth of buttons, and Bluetooth capability, it could be the ideal way to control your next build. Thanks to a recent project by [geggo], now you’ve even got an example you can follow.

A custom PCB holding an ESP32 and DRV8833 dual H-bridge motor controller is used to interface with standard LEGO motors using their stock block-like connectors. That means the board is a drop-in upgrade for whatever motorized creation you’ve already built.

Since the ESP32 obviously has WiFi in addition to Bluetooth, that also means this little board could be used to control LEGO projects over the local network or even Internet with some changes to the firmware.

Interestingly, while Valve officially enabled Bluetooth on the Steam Controller back in 2018, it sounds like some undocumented poking and reverse engineering was necessary to get it working here. That’s great for those of us who like a good hack, but if you’re more interested in just getting things working, [geggo] has been good enough to release the source code to get you started.

If you’re not interested in Bluetooth but want to get your creation up and moving, we’ve recently covered how one hacker used the ESP8266 to bring his LEGO train to life by integrating it into his smart home.

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Thunder Pack Is A Bolt Of Lightning For Wearables

March 25, 2020 by Kristina Panos 19 Comments

Do you need portable power that packs a punch? Sure you do, especially if you want to light up the night by mummifying yourself with a ton of LED strips. You aren’t limited to that, of course, but it’s what we pictured when we read about [Jeremy]’s Thunder Pack. With four PWM channels at 2.3 A each, why not go nuts? [Jeremy] has already proven the Thunder Pack out by putting it through its paces all week at Burning Man.

After a few iterations, [Jeremy] has landed on the STM32 microcontroller family and is currently working to upgrade to one with enough flash memory to run CircuitPython.

The original version was designed to run on a single 18650 cell, but [Jeremy] now has three boards that support similar but smaller rechargeable cells for projects that don’t need quite as much power.

We love how small and powerful this is, and the dongle hole is a great touch because it opens up options for building it into a wearable. [Jeremy] made a fantastic pinout diagram and has a ton of code examples in the repo. If you want to wade into the waters of wearables, let whimsical wearables wizard [Angela Sheehan] walk you through the waves.

Breaking Into A Secure Facility: STM32 Flash

March 24, 2020 by Bryan Cockfield 20 Comments

In a perfect world, everything would be open source. Our current world, on the other hand, has a lot of malicious actors and people willing to exploit trade secrets if given the opportunity, so chip manufacturers take a lot of measures to protect their customers’ products’ firmware. These methods aren’t perfect, though, as [zapb] shows while taking a deeper look into an STM microcontroller.

The STM32F0 and F1 chips rely on various methods of protecting their firmware. The F0 has its debug interface permanently switched off, but the F1 still allows users access to this interface. It uses flash memory read-out protection instead, which has its own set of vulnerabilities. By generating exceptions and exploiting the intended functions of the chip during those exceptions, memory values can be read out of the processor despite the memory read-out protection.

This is a very detailed breakdown of this specific attack on theses controllers, but it isn’t “perfect”. It requires physical access to the debug interface, plus [zapb] was only able to extract about 94% of the internal memory. That being said, while it would be in STM’s best interests to fix the issue, it’s not the worst attack we’ve ever seen on a piece of hardware.

ESP32-S2 Samples Show Up

March 23, 2020 by Al Williams 56 Comments

The ESP8266 is about six years old now and the ESP32 is getting more mainstream every day. Unsurprisingly, Espressif is developing even newer product and the ESP32-S2 was in the hands of some beta testers last year. Now it is finally landing as “final silicon” samples in people’s hands. [Unexpected Maker] got a few and a prototype development board for the chip and shared his findings in a recent video.

The ESP32-S2 has a single core LX7 running at 240 MHz along with a RISC-V-based coprocessor. Onboard is 320K of RAM and 128K of ROM. You might notice this is less than the ESP32. However, the device can support up to 128MB of external RAM and up to 1GB of external flash. It also supports USB, although the prototype module appears to have an external USB chip on it.

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Bee Counter Will Have You Up To Your Nectar In Hive Data

March 22, 2020 by Kristina Panos 14 Comments

While we admit that free honey sounds pretty good, beekeeping is not some set-it-and-forget-it hobby where you can just put bees in a box and come back in a month to collect the goods. With the world’s bee population in decline, it’s more important than ever to monitor the health of hives.

One way to do that is to count the bees as they leave and reenter the hive. You can use the data to determine how many workers are working, or to compare activity between multiple hives. If you notice the bees are gone for longer and longer periods, it’s probably because their nearby nectar sources are dwindling and they have to travel farther to find flowers.

This open-source bee counter built by [hydronics2] is designed to fit the opening of a standard hive. The bees can only buzz themselves back in by flying through one of 24 little IR break-beam gates. Our favorite thing about this build is the way [hydronics2] created the individual gates by sandwiching two boards together with headers as spacers. It’s such a simple and perfect solution.

It’s also pretty cool that the board is designed to be compatible with any Feather or ItsyBitsy board, so there are a lot of options for data handling. Check out the brief demo we planted after the break, and stick around for the build video. If you’d prefer a more hands-off approach, try computer vision.

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Google’s Pigweed For ARM Development Is A Nice Surprise

March 21, 2020 by Inderpreet Singh 25 Comments

Setting up an environment for Embedded Development was traditionally a pain and so vendors provide integrated development environments to help bridge the gap. Google has open-sourced their version of an embedded targeted environment designated as embedded-targeted libraries which they trademarked Pigweed.

Google trademarked Pigweed with the U.S. Patent and Trademark Office in February and it popped up on the Google Open Source Blog along with some details.

The repository contains what Google is calling modules but taking a better look reveals that it a little more than that. Packaged in a Python Virtual Environment is a number of tools including an ARM compiler, the clang-format tool and Python 3.8 interpreter which runs more than a few things. The modules that come with Pigweed assist developers by running micro-automations such as the pw_watch module that monitors files for change and triggers a build, test and even flash and debug on hardware. There is also a module that allows pre-submit checks such as linting and formatting.

Google still does not consider this offering production ready though from what we have seen so far, it is a great place for many to start experimenting with for their embedded development automation needs. Anyone tried it out yet?

If you have been inspired with the amazing powers of automation and want to dive in yourself, have a look at Software Development in BASH and Continuous Integration with Python.