Handheld Compass CNC Lets Teensy Do The Driving

If somebody asked you to visualize a CNC router, you’d probably think of some type of overhead gantry that moves a cutting tool over a stationary workpiece. It’s a straightforward enough design, but it’s not without some shortcomings. For one thing, the scale of such a machine can quickly become an issue if you want to work on large pieces.

But what if you deleted the traditional motion system, and instead let the cutting tool roam freely? That’s the idea behind the open source Compass Handheld CNC. Looking a bit more like a combat robot than a traditional woodworking tool, the Compass tracks its movement over the workpiece using a Teensy 4.1 microcontroller and four PMW3360 optical flow sensors. With a pair of handles that look like a flight yoke and a display that shows the router’s current position versus where it should be, the user can “drive” the tool to cut or carve the desired design.

Admittedly, the Compass doesn’t pack quite the same punch as a more traditional setup. Rather than a beefy spindle motor or a full-sized consumer router clamped up in the gantry, the Compass uses a Dremel 3000. It’s fine for routing out an engraving and other fine work, but you wouldn’t want to use it for cutting thick stock. To help keep the work area clear and prevent dust and chips from jamming up the works, the 3D printed body for the tool includes a connection for a dust collection system.

If this all seems familiar, you may be remembering a tool we first covered nearly a decade ago — the Shaper Origin. That router, which is still on the market incidentally, utilizes optical tracking and fiducial markers to keep track of its position. We’d be interested in seeing how well the Compass compares over large distances without similar reference points.

OpenWRT, But On An Unsupported Router

Everyone likes something cheap, and when that cheap thing is a router that’s supported by OpenWRT, it sounds like a win. [Hennung Paul] ordered a Wavlink WL-WN586X3 for the princely sum of 39 Euros, but was disappointed to find his device a rev. 2 board rather than the rev.1 board supported by the Linux distribution. Toss it on the failed projects pile and move on? Not at all, he hacked together a working OpenWRT for the device.

It’s fair to say that a majority of Hackaday readers will  have familiarity with Linux, but that’s something which runs on a sliding scale from “Uses Ubuntu a bit” all the way to “Is at one with the kernel”. We’d rate ourselves somewhere around halfway along that scale in terms of having an in-depth knowledge of userland and a working knowledge of some of the internals which make the operating system tick even if we’re apprehensive about tinkering at that level. [Henning] has no such  limitations, and proceeds to take the manufacturer’s distribution, itself a heavily modified OpenWRT, and make it his own. Booting over tFTP we’re used to, and we’re particularly impressed to see him using a Raspberry Pi as a surrogate host for the desoldered Flash chip over SPI.

It’s a long path he takes to get the thing working and we’re not sure we could follow it all, but we hope that the result will be a new device added to OpenWRT’s already extensive support list. It’s sometimes a shock to find this distro is now over two decades old.

Raspberry Pi Becomes Secure VPN Router

OpenWRT is a powerful piece of open-source software that can turn plenty of computers into highly configurable and capable routers. That amount of versatility comes at a cost, though; OpenWRT can be difficult to configure outside of the most generic use cases. [Paul] generally agrees with this sentiment and his latest project seeks to solve a single use case for routing network traffic, with a Raspberry Pi configured to act as a secure VPN-enabled router configurable with a smartphone.

The project is called PiFi and, while it’s a much more straightforward piece of software to configure, at its core it is still running OpenWRT. The smartphone app allows most users to abstract away most of the things about OpenWRT that can be tricky while power users can still get under the hood if they need to. There’s built-in support for Wireguard-based VPNs as well which will automatically route all traffic through your VPN of choice. And, since no Pi router is complete without some amount of ad blocking, this router can also take care of removing most ads as well in a similar way that the popular Pi-hole does. More details can be found on the project’s GitHub page.

This router has a few other tricks up its sleeve as well. There’s network-attached storage (NAS) built in , with the ability to use the free space on the Pi’s microSD card or a USB flash drive. It also has support for Ethernet and AC1300 wireless adapters which generally have much higher speeds than the built-in WiFi on a Raspberry Pi. It would be a great way to build a guest network, a secure WiFi hotspot when traveling, or possibly even as a home router provided that the home isn’t too big or the limited coverage problem can be solved in some other way. If you’re looking for something that packs a little more punch for your home, take a look at this guide to building a pfSense router from the ground up.

Portable Router Build: Finding An LTE Modem

Ever want your project equipped with a cellular interface for a data uplink? Hop in, I have been hacking on this for a fair bit! As you might remember, I’m building a router, I told you about how I picked its CPU board, and learned some lessons from me daily-driving it as a for a bit – that prototype has let me learn about the kind of extra hardware this router needs.

Here, let’s talk about LTE modems for high data throughput, finding antennas to make it all work, and give you a few tips that should generally help out.  I’d like to outline a path that increases your chances of finding a modem working for you wonderfully – the devices that we build, should be reliable.

Narrowing It Down

If you look at the LTE modem selection, you might be a little overwhelmed: Simcom, Qualcomm, uBlox, Sierra, Telit, and a good few other manufacturers package baseband chipsets into modules and adjust the chipset-maker-provided firmware. The modems will be available in many different packages, too, many of them solderable, and usually, they will be available on mPCIe cards too. If you want to get a modem for data connections for a project, I argue that you should go for mPCIe cards first, and here’s why.

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Portable Router Build: Picking Your CPU

I want to introduce you to a project of mine – a portable router build, and with its help, show you how you can build a purpose-built device. You might have seen portable routers for sale, but if you’ve been in the hacking spheres long enough, you might notice there are “coverage gaps”, so to speak. The Pi-hole project is a household staple that keeps being product-ized by shady Kickstarter campaigns, a “mobile hotspot” button is a staple in every self-respecting mobile and desktop OS, and “a reset device for the ISP router” is a whole genre of a hacker project. Sort the projects by “All Time” popularity on Hackaday.io, and near the very top, you will see an OpenVPN &Tor router project – it’s there for a reason, and it got into 2014 Hackaday Prize semifinals for a reason, too.

I own a bunch of devices benefitting from both an Internet connection and also point-to-point connections between them. My internet connection comes sometimes from an LTE uplink, sometimes from an Ethernet cable, and sometimes from an open WiFi network with a portal you need to click through before you can even ping anything. If I want to link my pocket devices into my home network for backups and home automation, I can put a VPN client on my laptop, but a VPN client on my phone kills its battery, and the reasonable way would be to VPN the Internet uplink – somehow, that is a feature I’m not supposed to have, and let’s not even talk about DNSSEC! Whenever I tried to use one of those portable LTE+WiFi[+Ethernet] routers and actively use it for a month or two, I’d encounter serious hardware or firmware bugs – which makes sense, they are a niche product that won’t get as much testing as phones.

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Linksys Velop Routers Caught Sending WiFi Creds In The Clear

A troubling report from the Belgian consumer protection group Testaankoop: several models of Velop Pro routers from Linksys were found to be sending WiFi configuration data out to a remote server during the setup process. That would be bad enough, but not only are these routers reporting private information to the mothership, they are doing it in clear text for anyone to listen in on.

Testaankoop says that while testing out the Pro WiFi 6E and Pro 7 versions of Velop routers, they discovered that unencrypted packets were being sent to a server hosted by Amazon Web Services (AWS). In these packets, they discovered not only the SSID of the user’s wireless network, but the encryption key necessary to join it. There were also various tokens included that could be used to identify network and user.

While the report doesn’t go into too much detail, it seems this information is being sent as part of the configuration process when using the official Linksys mobile application. If you want to avoid having your information bounced around the Internet, you can still use the router’s built-in web configuration menus from a browser on the local network — just like in the good old days.

The real kicker here is the response from Linksys, or more accurately, the lack thereof. Testaankoop says they notified them of their discovery back in November of 2023, and got no response. There’s even been firmware updates for the affected routers since then, but the issue is still unresolved.

Testaankoop ends the review by strongly recommending users avoid these particular models of Linksys Velop routers, which given the facts, sounds like solid advice to us. They also express their disappointment in how the brand, a fixture in the consumer router space for decades, has handled the situation. If you ask us, things started going downhill once they stopped running Linux on their hardware.

Ethernet For Hackers: Equipment Exploration

Last time, we talked about the surface-level details of Ethernet. They are fundamental to know for Ethernet hacking, but they’re also easy to pick up from bits and pieces online, or just from wiring up a few computers in your home network. Now, there’s also a bunch of equipment and standards that you will want to use with Ethernet – easy to find whether used or new, and typically as easy to work with. Let’s give you a few beacons!

Routers And Switches

Whenever you see a box with a few Ethernet ports, it’s either referred to as a router, or a switch, sometimes people will even use the word “hub”! Fortunately, it’s simpler than it may seem. A router is a smart device, typically with an OS, that ties two or more networks together – routing packers from one network to another, and typically taking care of things like handing out local IP addresses via DHCP. A switch merely helps Ethernet devices exchange packets between each other on the same level – it’s typically nowhere near as smart as a router gets. Oftentimes, a home router will contain a switch inside, so that you can plug in multiple of your home devices at once. That’s the main difference – a switch merely transmits packets between Ethernet-connected devices, while a router is a small computer taking care of packet forwarding between networks and possibly including an Ethernet switch on the side.
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