More meshtastic fun: Part 4: Range Testing

Of course, you want to know how far your signal is going in every direction. If you’re lucky, you have Kevin to test with who repeatedly types the word The into his app without letting you know if he’s actually seeing your messages. I am assuming that The is his auto-correct changing Test to The.

But if you actually want scientific data, you might want to look into the Range Testing feature (found in Module config). Assuming you’ve got two stable units, one goes mobile with you and one stays at a specific base. You set up both units for Range Test — the sender node and the receiver node. Set your stay-at-home node as the sender and your mobile node as the receiver, then drive around your area. You should be able to save results to a .csv file and the docs describe how to integrate that into mapping applications to visualize your received packets with their locations.

https://meshtastic.org/docs/configuration/module/range-test/

I hope to run a test this weekend. We’d love to hear about your results. Ideally, if you have multiple antennas and/or placement locations, this will give you real-world data, although time-consuming to generate, on how your signal makes it out into the world.

Meshtastic: Device options

As promised, another post to specifically discuss beginner Meshtastic device options. Whatever you order, if you’re in the US make sure you order the 915MHz version.

I started with a RAK Wisblock starter kit and a LilyGo T-Echo.

https://www.amazon.com/dp/B0CHKZJK9C

https://www.aliexpress.com/item/3256802839792781.html?spm=a2g0o.order_list.order_list_main.11.397d1802Rl4KK7

I ordered both because I was impatient. I knew the LilyGo was what I wanted to start with, but I also knew it would take a while, so I ordered the Wisblock to learn while I waited. And that worked out.

Some lessons from both:

  • They will come with an older firmware. First thing to do is to flash it with the latest stable firmware. http://flasher.meshtastic.org
  • Don’t fire it up without the antenna(s) connected. It could fry the unit. Just like in amateur radio.
  • Channel 0 should likely default to LongFast with its default key, I think that’s AQ== but don’t take my word for it.
  • If you want to try DC540’s custom channel, add it as channel 1. Name: DC540. 256-bit pre-shared key: OVRpanBCYjZ2WmVIZTRheVlSZDZZWGxUcElFNFRSaWo=
  • Install the app on your phone, pair with your unit (Pin is probably 123456), and then watch Nodes and Map for things to pop up.
  • Alternately, connect to your computer (use a USB-C cable that supports power AND data) and browse to client.meshtastic.org. Click “new device,” connect it to the serial port that’s obviously your device, and manage it that way. It’s a bit wonky and dies sometimes, just refresh the webpage to start over.

Ideally in the next 15-20 minutes you should see some local nodes pop up on your node list and map.

So far, the LilyGo seems more powerful than the Wisblock.

But something I noticed, when you’re looking at your node list, you can see what type of device the other nodes are running. One thing I noticed is that the farthest node I could see was running a Station G2. So that tells me that maybe the Station G2 transmits more powerfully. (Or maybe that user has a better antenna, or an external antenna).

Next, I started mucking around with MQTT. MQTT is the same type of networking, but over an MQTT server on the internet. If you’re frustrated by lack of nodes, you can light this up to see more and communicate with other weirdos around the world. But be aware, you’re cheating, and it’s going to cut into your radio knowledge improvement. Is it worth it? Probably.

When using MQTT through a mobile-paired device, you turn on “proxy through client.” If your device has its own wifi, turn that shit off. As far as I can tell, you can’t use MQTT through a serial-connected device without its own wifi.

That led me to my next purchase, the LilyGo T-Beam Supreme. It has built-in wifi.

The Station G2 also has its own wifi, but I’m not there yet.

More later. This should be enough to help you get started. Any questions? Join our Discord and ask in the Meshtastic learning channel.

Let’s all learn Meshtastic together!

So a recent discussion with one of our members led me to finally jump into Meshtastic. I wonder how many of y’all want to play along…

Meshtastic, in this particular use case, enables a text-based messaging system that uses LoRa radio, which is 915MHz in the US, which measures its general range in miles, but the Meshtastic firmware enables a self-assembling mesh network of these devices. There is also internet backbone capability via MQTT servers.

It FEELS like early BBS days to play on.

I think a lot of us entered the world of infosec from a perspective of wanting to be able to see the data that’s hidden in plain sight. At least I did. Starting in around fourth grade when I read a book on codes and ciphers, much of my tech fetish has been about finding that hidden information that’s just out of reach. And of course, much of that is in the radio spectrum.

I became licensed for amateur radio back in 2010, I think. I took, and passed, all three exams in the same session. I have a number of radios. Three or four HF radios, a mobile dual-band for 2m and 70cm, and probably three or four Baofeng handhelds sitting in a bin somewhere. I have made overseas contacts from my car, my home and elsewhere using a portable kit in a Pelican case. I’ve done voice contacts as well as data modes. I have made a couple of attempts to learn and retain CW. One day that will stick.

While I can’t imagine Meshtastic will ever take off as a widespread communciations platform, I do think it could be useful in a potential off-grid scenario, and is worth exploring and pushing its capabilities. Meshtastic devices are cheap, easy to work with and fun. My next post will talk about some specific devices that I’ve started playing with, and my experiences with them, and I’d love for someone else to jump in and provide other perspectives on their experiences.

Nova Labs: Consistent Meetup Space

Dear Members,

Based on recent exciting conversations, and a tour a few weeks ago, we are excited to announce a significant step forward in our efforts to grow our group and provide greater access to resources and learning opportunities. We are initiating a six-month trial membership at the Associate Level with Nova Labs, a state-of-the-art makerspace located in Fairfax, VA (www.nova-labs.org). This represents an opportunity for our organization to expand our reach and serve the community more effectively.

Why Nova Labs?

Nova Labs offers a facility equipped with advanced tools, workshops, and collaborative spaces designed to foster innovation, creativity, and learning. With this membership, we gain access to:

  • A centralized and consistent public location for member meetups, classes, and hands-on projects.
  • Access to equipment for formal classes, including 3D printers, soldering tools, reflow machine and pick and place.
  • A community of makers with similar passions.

Sustaining the Vision

To offset the cost of dues for Baab, the primary DC540 representative who will hold the membership, we are introducing an optional dues-based membership program. These contributions will directly support our ability to host regular classes, facilitate community outreach, and cover the costs of this trial partnership. Memberships can be set up quickly and easily via PayPal subscription buttons, (link in right column of website) with the following levels:

  • Observer: $10/month
  • Supporter: $20/month
  • Driver: $50/month
  • Hidden Hand: $100/month

We are not officially requiring membership dues, or tying membership to dues payments at this time. This is voluntary at this stage. By supporting at any level, you help us lay the groundwork for consistent meet-ups and our longer-term vision: establishing our own independent hackerspace.

We chose the Paypal subscription model because (a) Paypal already recognizes us as a nonprofit, and (b) the subscription model allows us to focus our limited efforts on generating content and activities rather than hounding people for dues. If you’re in, you’re in. If you’re not, you’re not. If we get enough buy in to sustain this, yay. If not, boo.

There is an alternate, privacy-focused option for membership as well, for those with concerns. However, payment info will not be published or released by us either way.

Join Us in Building the Future

This six-month trial is our first step in exploring what’s possible with the right resources and support. With your involvement, we aim to offer regular classes, foster collaboration, and extend our community outreach. At the end of this period, we’ll evaluate sustainability and work toward the exciting possibility of launching our own dedicated space.

We invite you to become a dues-paying member or attend our upcoming events at Nova Labs. Every contribution strengthens our mission to make creativity, innovation, and learning accessible to all.

Gather your questions for upcoming meetings, including tomorrow night’s virtual meeting.

Thank you for your unwavering support. Together, we are building something truly special!

Respectfully,

Treasurer
DC540

Custom wings add-on?

Hey, anybody interested in custom wings for your Chakra badge? I mean, some of you are certainly equipped to make them yourself, but say you’re not, or you’re a poor like most of us, but you’re artistically inclined, and you want something really personal on your wings. Hit us up, let us know what you want, and what you think a fair price is, and let’s get to burnin’ some plastic.

Badge Shipping Disabled! DEFCON BABY!

Badge shipping was just disabled from the ecommerce shop. You can still order a Chakra Badge, but only for pickup at Defcon. Around 60 badges are on their way to Las Vegas right now, and when they’re gone, they’re gone. We have not yet had deep discussions on whether there’ll be another run of these. It’ll be based on demand and other factors.

If you want to pick up at Defcon, we can accommodate you. We’ve got agents stationed at Sahara, Fontainebleu, the Marriotts, and even Paris. We’ll make it work for you.

We love the reaction we’re getting from recipients of this badge, and we’re super proud of it. In fact, we’re proud of ALL the amazing badges that are coming out of the woodwork this year!

Even if you don’t buy one of our badges this year, come hang out with us. We’ll be at the DCGroups room at least some of the time, and we’ll announce on our main Discord page when we’re planning to be somewhere.

Production firmware for the badge should be released at 8AM on Thursday, at which point the competition begins. Do your research, don’t get left behind!

Chakra Badge Status Update

We assembled, tested and packaged the last of the Chakra badges at last night’s meeting, the last in-person group meeting before the big event.

I’m going to disable shipping for badges tonight. So if you want one shipped, and it’ll make it to you in time, order it today.

I have added “in person pickup at Def Con” as a shipping option. So if you’d like to reserve one for pickup in Vegas, use that option. Then make sure we find each other during the con.

If you plan on getting one, you can either reserve one by ordering it that way, or you can take your chances that we’ll have some left at con. We’ve sold over half of our supply, and we’ll probably bring about 50 to Vegas with us.

We’re very happy with the community’s response to this badge, and the feedback we’ve gotten so far. We finished the prize trophies this week, and decided not to post them in advance, so they’ll be a surprise. Again, the first three in-person finishers and the first remote finisher of our badge challenge will get a trophy!

Turns out EVERYONE will have fo flash the final firmware. Never fear, it’s easy. Just make sure you have a USB-C cable and a computer. Or find one of us, we’ll probably be able to do it for you at con. The final firmware is done, we just didn’t have time to flash all the badges before packing them up, so they all have demo firmware on (which is beautiful, but not competitive).

Moving from a K40 to an 80W Omtech laser cutter/engraver

I’ve had my K40 for over a year now. I’ve burned leather, engraved and cut wood and acrylic. I’ve made hundreds of things for gifts, decorations and even made custom commissioned items for friends. It’s been great.

But it’s been a struggle. Don’t get me wrong, the K40 is a great starter machine for this kind of work, but it seems to be pushing its limits for cutting acrylic. It takes a bit of effort to calibrate, align and focus the laser correctly for maximum efficiency, which is needed for acrylic work.

Because I’m running up a deadline for mass-producing an item (wings for the DC540 Chakra badge) and production wasn’t meeting requirements, I decided to invest in a larger machine. Being budget conscious, I chose the manual focus version of the Omtech 80W machine.

It arrived last week, and I’m going to try and encapsulate my experience/lessons learned over the past week in this post.

I was relieved that the crate arrived unharmed. As my wife suggested, I’ll probably cut out that lovely tagline for wall art at some point. 🙂

After a bit of work uncrating and positioning the 200+ lb unit in the garage, I went through the installation and testing process.

The first test cut demonstrated two things. First, I had the focus wrong. Second, this thing has way more power than a K40. When the K40 is out of focus, it barely penetrates acrylic. When this thing is out of focus, it just makes thicker lines and doesn’t make it all the way through.

The first major difference between the two units is the size. The K40 can be lifted and moved from room to room by one person of average strength. It’s a tabletop unit. Not so with the 80W. I waffled between the garage and the basement for this unit, for various reasons. Garage = easier installation, easier venting of exhaust. Basement, better climate control, better integration with the rest of the lab. I opted for the garage. Sometime before winter, I will enlist three strong friends to help bring it into the basement and reconfigure exhaust.

Next obvious difference is the bed. The K40 ships with a fixed bed. It’s actually bolted on extension poles from the bottom of the cabinet. No provision exists in the unit to adjust the bed height. This is problematic. I ended up buying a lab jack and removing the extension poles. And cheap lab jacks are inherently not level. Oh well. I worked around it, but it was troubleshom. The 80W unit comes with linked greased screw adjusters for the entire bed, controllable by a single knob.

The K40 has no focus assistance at all. Trial and error (weighted heavily on the side of error) is used to find the correct focal point for your material. The 80W includes a red-dot focus tool. I simply turned the bed level adjustment knob until the red dot was at its smallest, and bam, I had good focus. The red dot is a little bit off in the X/Y coordinates from where the beam hits, but that’s easily adjustable as well (critical if you’re using the red dot to validate framing before cutting/engraving).

The mirror mounts on the K40 are not great. On mine, they look kind of like this, but the mirror is much closer to the surrounding ring than this photo. The result is that when you use tape as recommended to calibrate and center the beam on each mirror, invariable there ends up a bit of tape or burn residue on the mirror.

The new unit includes an offset frame for exactly that purpose. It’s not close to the mirror, so there’s no risk of tarnishing the mirror, yet it’s still aligned with the mount, so you can trust the alignment by putting tape on that frame and pulsing the laser.

The K40 has very little in the way of controls. A simple power level display, up/down buttons, an emergency stop button, and a pulse button. This unit has a full display which shows a representation of the pattern being cut/engraved, including a real-time cursor of what’s being cut.

My K40 would have required a controller upgrade to work with Lightburn — therefore I would have to set the power level on the panel, and use K40 Whisperer to send the operation code to the unit.

It was trivial to attach this unit to my PC using Lightburn, and since I already had a Lightburn license for my diode laser, I just had to add a DSP license to control the OMTech unit. Lightburn is miles beyond K40 Whisperer in functionality, including dragging, rotating, duplicating and removing design elements to suit your material before starting the job. Plus it’s easy to control design elements by color, assigning each color to line, fill or offset fill as desired.

Something I learned during this process, relating to my specific use case, is about vector vs raster. Most of what I do is engraving acrylic to foster illumination of patterns in acrylic. With the K40, vector engraving was fine for main design lines. With the new unit, the focal point is much smaller. Maybe that is an indication that the K40 was never completely dialed in on a good focal point, or maybe the beam and lens combination is just that much better on the 80W unit, but the end result is that I can no longer use vector lines for main lines of illumination. They’re fine for fine details and accents, but the big lines are going to need raster from now on. Raster takes a bit longer to cut, but that’s fine.

By the way, if you’re considering this unit or one like it, consider laser cooling solutions. It comes with a water pump, but from experience, I’ll tell you that the stock water pumps on these things are perilously unreliable, and if the pump fails you will lose your tube. Consider an industrial chiller. I ended up buying a CW3000 for the K40. It’s not a true chiller, more of an enhanced water pump, but the enhancements include alarms and alarm outputs for sensing flow failure or high temperatures. Since the new unit is in the garage, and the garage gets hot in the sweltering Virginia summer, I opted for a true chiller with compressor (CW5200) for this unit. Same safety features, but it actually cools the water. The last thing I want to do is replace a blown tube on this unit.

I wish I had upgraded to this unit earlier, but the K40 was a great training ground for CO2 laser work.

Chakra Badge Update, 2024-06-11

So the entire early sales allotment sold, and shipped. Sixty badges went out to you lovely people around the planet, and we are so grateful for your support!

For our next feat, we’ll be doing another smaller early sale batch shortly. We’re still having internal conversations about how many to put out there early and how many to hold for DEF CON.

One of the complications of DEF CON delivery is that now that the con is pretty much all in one space, and no longer directly connected to hotels, selling them at con just got much more complicated. Since we’re not allowed to sell in con space, and no connected hotels, we’ll have to be creative to find places to meet within folks’ already chaotic DEF CON schedules.

So all of that is factoring into our decisions.

Also, we’re trying out a new plugin for a birdseye view of all shipped badges, so if you get a NEW shipping notification AFTER you’ve already received your badge, don’t get too excited, it just means we populated a field. 🙂

-baab