If you've read Understanding MMDVM, you already know the hotspot on your shelf is really a stack — a modem board, MMDVMHost, a fistful of per-mode gateways, and a web dashboard — bundled together so you configure the whole thing from a browser instead of a command line. Two projects do that bundling for the overwhelming majority of hams: Pi-Star and WPSD. They share the same engine underneath. Where they part ways is who maintains them, how fresh they stay, and how much they ask of your hardware.
Start with what they have in common, because it's most of the machine. Neither project invents digital voice. Both wrap Jonathan Naylor G4KLX's MMDVM software suite — MMDVMHost and the per-mode gateways — along with the MMDVM_HS hotspot firmware and the cross-mode gateways contributed by Andy CA6JAU. When your radio keys up, it is that shared G4KLX code doing the actual work in either distribution. The signal on the air behaves identically. So this isn't a comparison of two radios; it's a comparison of two wrappers around the same radio — the packaging, the dashboard, and the upkeep.
Pi-Star is the work of Andy Taylor, MW0MWZ, and for most of the last decade it simply was digital voice for anyone who didn't want to hand-assemble a stack of software. It took the complex business of configuring MMDVMHost and six gateways and hid it behind a clean web page, so a newcomer could flash a card, fill in a callsign, and be on the air the same evening. That accessibility is why nearly every hotspot tutorial, forum thread, and YouTube walkthrough you'll find assumes Pi-Star.
Under the hood it has a few signature traits: the SD card runs read-only by default (you type rpi-rw to make changes and it locks itself back down, which is why the cards last), a distinctive red dashboard, and a family of command-line tools that all start with pistar-. The current release is V4.2.3 from April 2025, built on Debian Bullseye. Development went quiet for a stretch — roughly February 2024 through March 2025 — and then picked back up, which matters mostly for how current the underlying OS and security patches are.
WPSD began as one operator's replacement dashboard for Pi-Star — its full name, W0CHP-PiStar-Dash, still carries that history — built by an author whose callsign is W0CHP. It has since grown well past a reskin into its own full software distribution with a core development team, and its maintainers are emphatic on this point: it is not an overlay you paint onto Pi-Star, it's a distinct system. The images now ship on Debian Trixie, and the whole thing is rolling release: leave the hotspot powered on overnight and it quietly updates itself, so it tends to stay current without you thinking about it.
That freshness comes with a hardware floor. WPSD wants a multi-core board — a Raspberry Pi Zero 2W at minimum, on up through the Pi 3, 4, and 5 — and the project has formally dropped the original single-core Pi Zero and the OrangePi boards. In exchange you get features Pi-Star doesn't have out of the box: a “Live Caller” screen showing who's talking in real time, on-the-fly link managers that let you change reflectors and talkgroups for YSF, NXDN and P25 without walking through the whole config page, full DG-ID and APRS support, and 35-plus dashboard themes. One practical etiquette note: the WPSD team asks that support questions not be framed as Pi-Star comparisons — it's different enough that “but Pi-Star did X” isn't a useful starting point for them.
Everything above is packaging. There is now exactly one capability difference that a QSO can hear.
In July 2025, M17 was removed from MMDVM, and WPSD followed. Pi-Star V4.2.3_18 still has M17 — though its team has said they intend to remove it too.
So, today: if you want M17 out of the box, Pi-Star is the distribution that still has it. WPSD users need the WPSD-M17 community fork, or one of the M17-native paths (MSpot, N1ADJ's M17 Gateway).
This is the one place where “choose the wrapper, the radio underneath is identical” stops being true.
| Pi-Star | WPSD | |
|---|---|---|
| Maintainer | Andy Taylor, MW0MWZ | W0CHP + core dev team |
| Update model | Single image, manual updates | Rolling release, nightly self-update |
| Current base OS | Debian Bullseye (V4.2.3, Apr 2025) | Debian Trixie images |
| Hardware floor | Runs on the original single-core Pi Zero | Pi Zero 2W and up (multi-core required) |
| Filesystem | Read-only by default (rpi-rw to edit) | Read-write oriented |
| Dashboard | Classic red theme | 35+ themes, Live Caller, on-the-fly link managers |
| M17 out of the box | Yes — V4.2.3_18 (team intends to remove) | No — removed July 2025; community fork available |
| Docs & community | Enormous — years of tutorials assume it | Newer; own manual, Discord, Facebook group |
| Best when… | You want the default, the most tutorials, or the oldest hardware | You want newest features and hands-off freshness on modern hardware |
There's no wrong answer, and no lock-in worth worrying about — both are a card re-flash away from each other. If you're setting up a first hotspot on a Pi Zero 2W or better and you like the idea of it keeping itself current while you sleep, WPSD is the modern default — unless you want M17, in which case Pi-Star is currently the one that still ships it. If you're bringing an original single-core Pi Zero back to life, following a tutorial written for Pi-Star, or you simply want the most widely documented and battle-tested base in the hobby, Pi-Star is the safe, familiar choice. On the air, a QSO can't tell which one you ran on any mode but M17 — the same G4KLX code shaped the signal either way.
The big idea
Same MMDVM engine, two philosophies of upkeep. Pi-Star is the stable, ubiquitous baseline that made hotspots accessible to everyone; WPSD is the fast-moving distribution that keeps itself current on modern hardware. Choose the wrapper that fits your board and how much maintenance you want to do — the radio underneath is very nearly identical. The one exception is M17: Pi-Star still ships it, WPSD no longer does.
A noncommercial hobby reference compiled by N6JET, gathered from public sources and shared freely for anyone interested in amateur digital voice.