Hackaday Prize Entry: 3D Printed Linear Actuator Does 2kg+

The rabbit hole of features and clever hacks in [chiprobot]’s NEMA17 3D Printed Linear Actuator is pretty deep. Not only can it lift 2kg+ of mass easily, it is mostly 3D printed, and uses commonplace hardware like a NEMA 17 stepper motor and a RAMPS board for motion control.

The main 3D printed leadscrew uses a plug-and-socket design so that the assembly can be extended easily to any length desired without needing to print the leadscrew as a single piece. The tip of the actuator even integrates a force sensor made from conductive foam, which changes resistance as it is compressed, allowing the actuator some degree of feedback. The force sensor is made from a 3M foam earplug which has been saturated with a conductive ink. [chiprobot] doesn’t go into many details about his specific method, but using conductive foam as a force sensor is a fairly well-known and effective hack. To top it all off, [chiprobot] added a web GUI served over WiFi with an ESP32. Watch the whole thing in action in the video embedded below.

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Practical IoT Cryptography on the Espressif ESP8266

The Espressif ESP8266 chipset makes three-dollar ‘Internet of Things’ development boards an economic reality. According to the popular automatic firmware-building site nodeMCU-builds, in the last 60 days there have been 13,341 custom firmware builds for that platform. Of those, only 19% have SSL support, and 10% include the cryptography module.

We’re often critical of the lack of security in the IoT sector, and frequently cover botnets and other attacks, but will we hold our projects to the same standards we demand? Will we stop at identifying the problem, or can we be part of the solution?

This article will focus on applying AES encryption and hash authorization functions to the MQTT protocol using the popular ESP8266 chip running NodeMCU firmware. Our purpose is not to provide a copy/paste panacea, but to go through the process step by step, identifying challenges and solutions along the way. The result is a system that’s end-to-end encrypted and authenticated, preventing eavesdropping along the way, and spoofing of valid data, without relying on SSL.

We’re aware that there are also more powerful platforms that can easily support SSL (e.g. Raspberry Pi, Orange Pi, FriendlyARM), but let’s start with the cheapest hardware most of us have lying around, and a protocol suitable for many of our projects. AES is something you could implement on an AVR if you needed to.

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BBSing with the ESP8266

Modems have been around for longer than the web, and before we had Facebook we had the BBS scene. Somewhat surprisingly, people are still hosting BBSes, but have fun finding a landline these days. [Blake Patterson] is one of the leading aficionados of retocomputers, and recently he took it upon himself to review an interesting new device. It’s the WiFi232 Internet Modem, a device that turns a WiFi connection into something a computer with a 25-pin RS-232 connector can understand.

The WiFi232 is made by [Paul Rickards], and given the last few years of WiFi-enabled retrocomputing projects, it’s exactly what you would expect. Onboard the WiFi232 is an ESP8266 module emulating the Hayes AT command set. Baud rates from 300 to 115200 are supported, with power provided through a USB mini jack or solder terminals.

[Blake]’s computer den is the stuff of legend, and as such he has more than enough toys to test out this universal WiFi to Serial converter. Devices used in the test include the Apple //c, IIe, Amiga 1000, and TI-99/4A. In short, everything works just like it should. [Blake] was able to pull up the extant bulletin boards on his collection of ancient computers. You can check out [Blake]’s review of the WiFi232 below

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New Brain for Smart Vacuum

The ESP8266 has found its way into almost everything now. With its tiny size, low price tag, and accessible programmer, it’s perfect for almost any application that requires WiFi. [HawtDogFlvrWtr] decided that will all of the perks of the platform, an ESP8266 was practically begging to be shoehorned into his automatic vacuum cleaner. This isn’t a Roomba, though, it’s a Neato that now has a custom WiFi interface.

The new WiFi modification comes with some additional features as well. First of all, it ditches the poorly designed default user interface (often the most annoying proprietary component of any consumer product). In addition, the vacuum can now be placed on a completely custom schedule and can also be deployed at the push of a button. Now that it has a custom interface, it can report its status over the network to a phone or other computer as well.

[HawtDogFlvrWtr] is still developing his project and it looking for some help beta testing his new platform. He also has how to videos on his project page if you’re in the process of tearing apart your own. There are many other ways of modifying vacuum cleaners to add other useful features as well.

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ESP8266 MQTT Remote Gate Entry

Do you live in an area where you (or your car) are locked in by a gate? If so, you may know how [Alexander Else] feels about letting his guests in and out constantly with a remote control — it’s just not convenient. [Alexander] could have just purchased some extra remote controls and passed them out, but they aren’t exactly as cheap as party favors. Not to mention it wouldn’t make sense to hand one out to every single visitor anyway. Because the gate is a community gate, hacking the actual gate system was not an option. There was only one thing he could do — hack the remote control!

Like just about every other hacker, [Alexander] had a spare ESP8266-based board lying around. [Alexander] also had a couple of spare relays which he used to control the two buttons on his designated ‘sacrifice’ remote — one relay per button. After throwing these parts together with a couple of supporting bits of electronics, the hardware was done.  Now [Alexander] can just set up HTTP Request Shortcuts on each trusted visitor’s smartphone. From there on out they can open/close the gates themselves!

Originally, he was using IFTTT to trigger the string of events that make it all happen, but there was a delay of about 8 seconds (from trigger to relay action). [Alexander] was not having this so he turned to the HTTP Request Shortcuts app. When he made this change, the delay disappeared. Continue reading “ESP8266 MQTT Remote Gate Entry”

Hijacking the Sonoff OTA Mechanism

ITEAD’s Sonoff line is a range of Internet-of-Things devices based around the ESP8266. This makes them popular for hacking due to their accessibility. Past projects have figured out how to reflash the Sonoff devices, but for [mirko], that wasn’t enough – it was time to reverse engineer the Sonoff Over-The-Air update protocol.

[mirko]’s motivation is simple enough – a desire for IoT devices that don’t need to phone home to the corporate mothership, combined with wanting to avoid the labor of cracking open every Sonoff device to reflash it with wires like a Neanderthal. The first step involved connecting the Sonoff device to WiFi and capturing the traffic. This quickly turned up an SSL connection to a remote URL. This was easily intercepted as the device doesn’t do any certificate validation – but a lack of security is sadly never a surprise on the Internet of Things.

After capturing the network traffic, [mirko] set about piecing together the protocol used to execute the OTA updates. After a basic handshake between client and server, the server can ask the client to take various actions – such as downloading an updated firmware image.  After determining the messaging format, [mirko] sought to create a webserver in Python to replicate this behaviour.

There are some pitfalls – firmware images need to be formatted slightly differently for OTA updates versus the usual serial upload method, as this process leaves the stock bootloader intact. There’s also the split-partition flash storage system to deal with, which [mirko] is still working on.

Nevertheless, it’s great to see hackers doing what they do best – taking control over hardware and software to serve their own purposes. To learn more, why not check out how to flash your Sonoff devices over serial? They’re just an ESP8266 inside, after all.

Digital Clock Goes with the Grain

This good-looking clock appears to be made out of a block of wood with LED digits floating underneath. In reality, it is a block of PLA plastic covered with wood veneer (well, [androkavo] calls it veneer, but we think it might just be a contact paper or vinyl with a wood pattern). It makes for a striking effect, and we can think of other projects that might make use of the technique, especially since the wood surface looks much more finished than the usual 3D-printed part.

You can see a video of the clock in operation below. The clock circuit itself is nothing exceptional. Just a MAX7218 LED driver and a display along with an STM32 ARM processor. The clock has a DHT22 temperature and humidity sensor, as well as a speaker for an alarm.

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