Installing the Monster fork

The Monster fork (Ho52198/ats-mini-monster) builds on the official firmware and carries the same MIT licence as its parent. What the app does once it is running — the wider status line, the extra commands, and the large caveat attached to all of it — is in Alternative firmware. This page is about getting it onto a radio, which is the awkward part.

No releases, but there are binaries

The repository publishes no tagged releases and no tags at all. There is nothing on a releases page to download, and nothing for the installer’s release list to find — that list reads the official firmware project only.

Prebuilt images exist anyway. Three of them are committed straight into the repository, in a flash/ folder on the default branch: ats-mini.ino.bootloader.bin, ats-mini.ino.partitions.bin and ats-mini.ino.bin. Those are the same three files an official release archive contains, minus the merged image and minus the changelog. The README does not mention the folder, which is presumably why most people conclude there is nothing to download.

A small manifest-full.json sits beside them and records the flash addresses — 0x0, 0x8000 and 0x10000, the same layout as the official firmware — and the build’s name. Read that file before you flash anything: it is the only place the fork states which upstream version it was built from. It read 2.33+monster when this was written, so the baseline is an older official release rather than the newest one.

An index.html web-installer page sits in the same folder, but GitHub Pages is not switched on for the repository, so it is not live anywhere. It is a file you would have to serve yourself, not a link you can open.

One build, and it is the octal one

There is a single set of binaries and it is built for octal PSRAM. Running it on the wrong board is not a clean refusal. On the one radio this project has seen it run on, PSRAM failed to initialise: the radio printed the error over the serial port, never sent a status frame, and left the app with nothing to control — the detail is in Alternative firmware. So check which board you have first: Installing firmware explains how, and the installer will read it off the chip for you in a few seconds.

The fork’s build configuration does carry both PSRAM profiles, esp32s3-ospi and esp32s3-qspi, and its README documents the one-line arduino-cli compile --profile invocation for each. A quad build is therefore a compile away — but only a compile, since nobody has published one.

What this site’s installer can do with it

Not the whole job. The installer reads the variant out of a release archive’s folder name, and there is no archive here at all, so there is nothing to check your hardware against. That leaves the raw .bin route, which takes one file at a time and works out where it belongs from the image’s own header:

• ats-mini.ino.bin loads. It is an application image, so the app offers it at 0x10000 — which is the correct address for it.
• ats-mini.ino.bootloader.bin and ats-mini.ino.partitions.bin are both refused. Neither is a complete image or a standalone application image, so no flash address can be read out of either, and the app will not guess one.
• There is no merged image, so there is no single file that installs the lot.

What that adds up to: the installer can write the fork’s application over a radio that already runs official firmware, with the override ticked and no variant check behind it. That assumes the bootloader and partition table already on the radio match the ones this build expects — a fair assumption given the manifest lists the same three addresses as the official firmware, but an assumption. A complete install of all three files needs one of the manual routes in Installing firmware.

Before you flash it

• Back up first, and mean it. There is no Monster release to roll back to, so the copy you take now is the only route back to the firmware you have — Firmware backup and recovery.
• Confirm your PSRAM type. This binary on a board it was not built for gives you a radio that starts and then cannot do anything, which looks alarming and is entirely avoidable.
• Read the manifest for the upstream version the build is based on, so you know what you are giving up relative to the official firmware.

One honest caveat about what happens next: the app carries a full Monster profile, but it was written from the fork’s documentation rather than from a working radio, and none of it has been exercised against one. Alternative firmware sets out exactly which parts are declared and which are tested.