Haven 2 Is Here

I've been sitting on this for a while. Quietly testing, breaking things, rebuilding, and not saying a word about it. But it's ready now, and I'm genuinely fired up about what it means for this project.

Haven 2 is a Raspberry Pi 5 running OpenWRT with the brand new Morse Micro MM8108 — the newest Wi-Fi HaLow chip on the market. It's an off-grid IP mesh radio you build yourself from off-the-shelf parts, for about $246. And it overlaps — in real, measurable ways — with military mesh systems that cost 80 times more.

Here's what changed, what I learned getting it working, and why I think this matters.

The Pi 5 Problem

Haven 1 hit a nerve. Hundreds of people built their own nodes. Photos showed up in my feed every week. People I never expected to hear from reached out. But that build ran on the Pi 4, and the most common question I got was always the same: when will this work on a Pi 5?

So I emailed Morse Micro directly. One of their lead engineers told me they were working on Pi 5 support in their upcoming OpenWRT 24-based release. But then he mentioned that "a clever developer in the community" might be able to backport the hardware definitions into the current stable tree and get it working now.

That was enough to bait me into rolling up my sleeves.

Getting It to Boot

In practice, "backport" meant pulling driver support for the MM8108 — a chip that didn't exist yet in the stable OpenWRT 23.05 tree — out of a development branch, and then debugging every incompatibility that came up at build time. For several days.

Anyone who's built OpenWRT from source knows what that's like. It's a CPU-bound process that takes 2–3 hours per iteration on a normal machine. I was iterating constantly — changing a flag, rebuilding, hitting a new error, changing another flag.

I ended up spinning a VM on GCP to speed things up: 60 cores, 256 GB of RAM, an extreme persistent disk maxing read/write speeds. That machine costs $6,000/month to run. I only needed it for a few days. But it knocked each build cycle from hours to minutes, which is the only reason I kept my sanity.

Eventually, we got an RPi 5 image that actually booted. Then the real testing started.

What's Under the Hood

For the uninitiated: Haven is what the industry calls a MANET — Mobile Ad Hoc Network. It's an IP mesh radio with a fully digital architecture. Solid state, headless, battery-powered. You carry it, and it gives you and your team a private network wherever you are — no towers, no ISP, no internet required.

Your phone, laptop, or tablet connects to it over standard 2.4 or 5 GHz Wi-Fi, same as any home router. The magic is in the backhaul link between nodes: sub-GHz 802.11ah HaLow, operating in the same spectrum neighborhood as LoRa and Meshtastic. Lower frequency means longer range. Done right, you're looking at several kilometers per hop.

Morse Micro holds the world record here — 10 miles at 2 Mbps, set with the previous-generation MM6108 chip. Haven 2 runs the MM8108: better range, better throughput, same socket. If you built a V1 using the Haven Guide, the new module drops right in.

All the radios are bridged, so your devices never know they're talking over HaLow long-haul. They just see Wi-Fi. And any node on the mesh can share an internet uplink — plug a Starlink terminal or cellular modem into one node, and the whole mesh gets backhaul.

How It Stacks Up Against the Military Version

I kept wondering how the compute side of Haven compared to what the DoD is actually fielding. So I pulled the specs.

Quick note on pricing: neither Persistent Systems nor Sylvus publishes numbers publicly. The figures I'm referencing came from someone with access to DoD procurement data who reached out with the actuals. Your tax dollars at work.

Persistent's spec page lists the MPU5's onboard computer as a 1 GHz quad-core ARM, 2 GB of RAM, 128 GB of flash. Here's the comparison:

Spec	MPU5 (Military)	Haven 2 (Pi 5)
Processor	1 GHz quad-core ARM	2.4 GHz quad-core ARM (Cortex-A76)
RAM	2 GB	Up to 8 GB LPDDR4X
Storage	128 GB flash	Up to 512 GB microSD
Per-core throughput	Baseline	3–4x higher at same wattage
OS	Wave Relay (proprietary)	OpenWRT (open source)
Price	~$20,000	~$246

On ruggedization, they have us beat — military radios survive EMPs, Carrington events, the whole nine yards. I'm pretty sure if I sneeze on mine, it'll combust. We'll get to an enclosure eventually.

The MPU5 runs Android. Haven runs OpenWRT — the most widely used Linux-based routing OS. And military radios operate on licensed spectrum, so they can push power and bandwidth in ways we can't. I want to keep Haven unlicensed and see how far we can take that approach.

A guy in his garage with a 3D printer and a GitHub account can now build a router that outperforms what most people buy off the shelf — and overlaps with what the DoD pays vendor rates for in the mesh radio space. That's the part that gets me fired up.

Mesh Protocol and Encryption

Haven 2 supports 802.11s — the standard Wi-Fi mesh protocol — which works fine for most setups. But the real upgrade is BATMAN-adv. It's a smarter routing layer that operates at Layer 2, meaning the entire mesh looks like a single switch to every device on it. Roaming between nodes, failover, multicast — it all just works without your devices needing to know anything about the mesh topology.

All Wi-Fi links run WPA3-SAE encryption. Most home routers still don't support WPA3, which is kind of embarrassing for the industry. Haven does it out of the box.

Battery: 18,000 mAh from Off-the-Shelf Cells

V1 ran on two 21700 cells — about 10,000 mAh total. For context, the L3 Harris military radio battery commonly used in the field holds around 7,000 mAh.

The Pi 5 draws more power than the Pi 4 did. You can technically run it on two 21700s, but you have to feed it through USB-C — the pogo pins on the GPIO header can't deliver enough current for the new board.

So I swapped in a Waveshare hat that takes four cells, bringing total capacity to 18,000 mAh. That's almost three times what the L3 Harris battery holds, from cells you can buy at any battery shop.

Field Tests

The best part of any build is running it outside and seeing what breaks. A few things we tested:

Vehicle-to-vehicle mesh at highway speed. One Haven node per car, magnetic HaLow antennas on the hoods. Phones connected to the local node's Wi-Fi, cellular data off. We FaceTimed each other over the private mesh at 70 MPH. No carrier, no internet. Just two Haven nodes and a HaLow link between them.

Live video recon with a micro-node. We built a tiny node from a Xiao board with an FPV camera, strapped it to our dog Bruno, and ran a live video feed through ATAK over the Haven mesh. The link held while he tore through trees and behind structures. Haven 2 is compatible with any HaLow node — no special hardware required on the remote end.

ADS-B air traffic on the mesh. I plugged a $30 USB SDR dongle into the Pi and pointed it at a 915 MHz antenna — not even the right frequency for ADS-B (that's 1090 MHz). It still pulled live aircraft data into ATAK: flight paths, speed, altitude, all rendered on the map. No internet. With a proper ADS-B antenna, coverage would be significantly better. The point is that the same node running your mesh comms can simultaneously give you real-time air traffic awareness.

Supply Chain

The Pi board comes out of Wales. The HaLow chip is engineered in Australia. Most peripherals are still out of Shenzhen. Not perfect, but very likely better provenance than whatever modem came free from your ISP.

Build One

Everything is open. Code, schematics, all of it. You don't need anyone's permission.

GitHub Repo

If you build it and decide mesh networking isn't your thing — cool. Pull the SD card, flash Home Assistant or Raspberry Pi OS, and you've still got a solid Pi 5 setup. Nothing goes to waste.

The full build process — including all the V2 changes, the backported firmware, power wiring, and antenna configs — is documented in the Haven Guide. You don't need it to build one; the code and schematics are public. But the guide contains my personal bench notes from over a year of testing, and buying it helps fund the next round of development.

The whole build still comes in under $450 at the high end. For the same class of capability the DoD pays five figures for.

If you want to understand the full stack behind this — HaLow, LoRa, mesh protocols, how all the layers fit together — the Parallel Primer covers that ground from silicon to signal.

I'd love to see Ubiquiti open-source their firmware. I'm not holding my breath.