Apple HomeKit Accessory Development Kit Gets More Accessible

December 27, 2019 by 6 Comments

Every tech monopoly has their own proprietary smart home standard; how better to lock in your customers than to literally build a particular solution into their homes? Among the these players Apple is traditionally regarded as the most secretive, a title it has earned with decades of closed standards and proprietary solutions. This reputation is becoming progressively less deserved when it comes to HomeKit, their smart home gadget connectivity solution. In 2017 they took a big step forward and removed the need for a separate authentication chip in order to interact with HomeKit. Last week they took another and released a big chunk of their HomeKit Accessory Development Kit (ADK) as well. If you’re surprised not to have heard sooner, that might be because it was combined the the even bigger news about Apple, Amazon, the Zigbee Alliance, and more working together on more open, interoperable home IoT standards. Check back in 2030 to see how that is shaping up.

“The HomeKit ADK implements key components of the HomeKit Accessory Protocol (HAP), which embodies the core principles Apple brings to smart home technology: security, privacy, and reliability.”
– A descriptive gem from the README

Apple’s previous loosening-of-restrictions allowed people to begin building devices which could interact natively with their iOS devices without requiring a specific Apple-sold “auth chip” to authenticate them. This meant existing commercial devices could become HomeKit enabled with an OTA, and hobbyists could interact in sanctioned, non-hacky ways. Part of this was a release of the (non-commercial) HomeKit specification itself, which is available here (with Apple developer sign in, and license agreement).

Despite many breathless mentions in the press release it’s hard to tell what the ADK actually is. The README and documentation directory are devoid of answers, but spelunking through the rest of the GitHub repo gives us an idea. It consists of two primary parts, the HomeKit Accessory Protocol itself and the Platform Abstraction Layer. Together the HAP implements HomeKit itself, and the PAL is the wrapper that lets you plug it into a new system. It’s quite a meaty piece of software; the HAP’s main header is a grueling 4500 lines long, and it doesn’t take much searching to find some fear-inspiring 50 line preprocessor macros. This is a great start, but frankly we think it will take significantly more documentation to make the ADK accessible to all.

If it wasn’t obvious, most of the tools above are carefully licensed by Apple and intended for non-commercial use. While we absolutely appreciate the chance to get our hands on interfaces like this, we’re sure many will quibble over if this really counts as “open source” or not (it’s licensed as Apache 2.0). We’ll leave that for you in the comments.

New Part Day: Alexa Connect Kit Now Available For Sale

November 11, 2019 by 8 Comments

People who were subscribed to updates on the Alexa Connect Kit (ACK) would recently have received an email informing that this kit is now available for sale. Last time we covered the ACK was back in September of 2018, the ‘release’ moniker meant ‘preview’ and there wasn’t any hardware one could actually purchase.

Over a year a later it seems that we can now finally get our grubby mitts on this kit that should enable us to make any of our projects Alexa-enabled. What this basically seems to mean is that one can spend close to 200 US dollars on an Arduino Zero and an Arduino shield-mounted WM-BN-MT-52 module from USI (though not listed on their site, but similar to the WM-BN-BM-22?) that integrates a 192 MHz Cortex-M MCU and a WiFi/Bluetooth module, as summarized on the Amazon Developer page for the ACK.

Continue reading “New Part Day: Alexa Connect Kit Now Available For Sale” →

Reverse-Engineering Xiaomi IoT Firmware

October 24, 2019 by 13 Comments

IoT devices rarely ever just do what they’re advertised. They’ll almost always take up more space than they need to – on top of that, their processor and memory alone should be enough to run a multitude of other tasks while not necessarily compromising the task they were built to do.

That’s partially the motivation for rooting any device, but for Xiaomi devices, it’s a bit more fun – that is to say, it’s a little bit harder when you’re reverse engineering its firmware from scratch.

Similar to his other DEF CON 26 talk on modifying ARM Cortex-M firmware, [Dennis Giese] returns with a walkthrough of how to reverse-engineer Xiaomi IoT devices. He starts off talking about the Xiaomi ecosystem and the drawbacks of reusing firmware across all the different devices connected to the same cloud network before jumping into the walkthrough for accessing the devices.

Continue reading “Reverse-Engineering Xiaomi IoT Firmware” →

Open Hardware E-Ink Display Just Needs An Idea

May 12, 2019 by 25 Comments

Its taken awhile, but thanks to devices like the Amazon Kindle, the cost of e-ink displays are finally at the point where mere mortals such as us can actually start using them in our projects. Now we’ve just got to figure out how to utilize them properly. Sure you can just hook up an e-ink display to a Raspberry Pi to get started, but to truly realize the potential of the technology, you need hardware designed with it in mind.

To that end, [Mahesh Venkitachalam] has created Papyr, an open hardware wireless display built with the energy efficiency of e-ink in mind. This means not only offering support for low-energy communication protocols like BLE and Zigbee, but keeping the firmware as concise as possible. According to the documentation, the end result is that Papyr only draws 22 uA in its idle state.

So what do you do with this energy-sipping Bluetooth e-ink gadget? Well, that part is up to you. The obvious application is signage, but unless you’re operating a particularly well organized hackerspace, you probably don’t need wireless dynamic labels on your part bins (though please let us know if you actually do). More likely, you’d use Papyr as a general purpose display, showing sensor data or the status of your 3D printer.

The 1.54 inch 200×200 resolution e-ink panel is capable of showing red in addition to the standard grayscale, and the whole thing is powered by a Nordic nRF52840 SoC. Everything’s provided for you to build your own, but if you’d rather jump right in and get experimenting, you can buy the assembled version for $39 USD on Tindie.

Transcending The Stack With The Right Network Protocol

April 9, 2019 by 14 Comments

The increase in network-connected devices the past years has been something of a dual-edged sword. While on one hand it’s really nice to have an easy and straight-forward method to have devices talk with each other, this also comes with a whole host of complications, mostly related to reliability and security.

With WiFi, integrating new devices into the network is much trickier than with Ethernet or CAN, and security (e.g. WPA and TLS) isn’t optional any more, because physical access to the network fabric can no longer be restricted. Add to this reliability issues due to interference from nearby competing WiFi networks and other sources of electromagnetic noise, and things get fairly complicated already before considering which top-layer communication protocol one should use. Continue reading “Transcending The Stack With The Right Network Protocol” →

Finding The Goldilocks Cell Module

January 4, 2019 by 29 Comments

If adding a cell modem is dealing with a drama queen of a hardware component, then choosing from among the many types of modules available turns the designer into an electronics Goldilocks. There are endless options for packaging and features all designed to make your life easier (or not!) so you-the-designer needs to have a clear understanding of the forces at work to come to a reasonable decision. How else will Widget D’lux® finally ship? You are still working on Widget D’lux®, aren’t you?

OK, quick recap from last time. Cell modems can be used to add that great feature known as The Internet to your product, which is a necessary part of the Internet of Things, and thus Good. So you’re adding a cell modem! But “adding a cell modem” can mean almost anything. Are you aiming to be Qualcomm and sue Apple build modems from scratch? Probably not. What about sticking a Particle Electron inside to bolt something together quickly? Or talk to Telit and put a bare modem on a board? Unless you’re expecting to need extremely high volume and have a healthy appetite for certification glee, I bet you’ve chosen to get a modem with as many existing certifications as possible, which takes us to where we are today. Go read the previous post if you want a much more elaborate discussion of your modem-packaging options and some of the trade offs involved. Continue reading “Finding The Goldilocks Cell Module” →

Interfacing Philips Hue Lights With Everything

December 10, 2018 by 46 Comments

The Internet of Things is eating the world alive, and we can’t buy incandescent light bulbs anymore. This means the Internet is now in light bulbs, and with that comes some special powers. You can turn lights on and off from a botnet. You can change the colors. This is the idea for the Philips Hue system, which is well respected among people who like putting their lights on the Internet. There are other brands — and you can make your own — but the Hue system does work pretty well.

This is what led [Marius] to create software to interface various electronics with the Hue system. It’s a project called diyHue, and already there’s a vibrant community of devs creating their own smart lights and connecting them to the Internet.

The software for this project is built in Python, and is designed to run on certain single board computers. This allows the SBC to connect to the Hue bridge so Hue bulbs can be controlled, a MiLight hub so MiLight bulbs can be controlled, or, with the addition of a ZigBee radio, all those ZigBee devices can be controlled. Right now the only thing that doesn’t work is Google Home because it requires a remote API, the Home & Away feature from the Hue app (again, remote API), and the Eneco Toon.

There really are a fantastic number of devices this software works with, and if you’re building out your Internet-connected home lighting solution, this is one piece of software you need to check out. Thanks to [cheesemarathon] for bringing our attention to this. He also liked it so much he’s now contributing to the GitHub. Very cool.