# UM24 / UM25 / UM34 Family Compatibility Note

This note records what can currently be inferred from the archived `UM24` resource bundle about the `UM24C`, `UM25C`, and `UM34C` family.

## Confirmed Facts

- the archived manual is explicitly labeled `UM24C`
- the archived PC software package is explicitly labeled `UM24C`
- the `UM24` line is known to use classic Bluetooth serial-port style communication and is not intended to be supported by this application
- the newly imported `User_Manual_UM34C.pdf` uses mixed model labels internally: `UM25/UM25C` in one heading and `UM34/UM34C` in the technical parameter section
- the same newly imported PDF titles its app section `UM34C Android APP Instruction`
- a separate `UM25` manual has now been imported as `Documentation/Research Resources/Manuals/UM25 User Manual.pdf`
- the `UM25` manual explicitly includes Android app, iOS app, and Windows PC software sections for `UM25C`
- imported `HM-10` and `DX-BT18` module references both support the `FFE0` transport family already assumed by the app for `UM25C` / `UM34C`
- the `DX-BT18` manual explicitly describes a dual-mode module with BLE for iOS and SPP-style behavior for desktop / Android environments
- the two Android APKs are branded more generically around RuiDeng / `UM Meter`
- the duplicate "3 in 1" PDF is byte-for-byte identical to the already imported `UM24C` manual

## Quick Inspection Results

- quick string scans of the Android APKs surfaced RuiDeng branding but did not immediately expose model-specific names such as `UM25` or `UM34`
- quick string scan of the PC software archive surfaced `UM24C` labeling and installer/runtime filenames, but no direct `UM25` or `UM34` hits
- the imported `UM34C` PDF reads like an operational manual for the same product family and strengthens the case that RuiDeng reused documentation structure across closely related models
- the newly added `UM25` PDF likely gives us a cleaner model-specific source for separating `UM25` behavior from `UM24C` and `UM34C`, but it still needs review
- the reviewed `UM25` PDF confirms that `UM25C` had official Android, iOS, and Windows software support, which makes it a better primary product reference than the older `UM24C` manual
- the imported `HM-10` and `DX-BT18` radio references make the current `FFE0` / `FFE1` BLE transport assumption for the UM family significantly more credible
- the `DX-BT18` dual-mode description offers a plausible explanation for why UM-family material mixes iOS BLE workflows with Windows serial-port workflows
- the existing external project note for `floriandotorg/um24c` remains the stronger indication that `UM24C`, `UM25C`, and `UM34C` are closely related at the protocol level

## Working Assumption

- use the imported Android applications and vendor contact document as family-level reference material that may still help with `UM25C` and `UM34C`
- exclude classic-Bluetooth `UM24` support from current application scope
- use the imported `User_Manual_UM34C.pdf` as a family-level UI and feature reference, while keeping its model-specific claims tentative
- use the reviewed `UM25` manual as the current best product-level reference for `UM25C`
- use the imported `HM-10` / `DX-BT18` references as transport-level support for the existing UM-family radio model, while still treating the exact installed module as unconfirmed until hardware verification
- use the imported manual and PC software primarily as `UM24C` references until stronger cross-model evidence is found

## Practical Implication

- focus implementation effort on the app-supported `UM25C` / `UM34C` direction rather than classic-Bluetooth `UM24`
- treat the `UM25` manual as the best current guide for user-visible features and supported control surfaces
- for payload decoding and Bluetooth behavior, keep comparing `UM25C` and `UM34C` observations against `UM24C` notes
- for transport assumptions, `FFE0` / `FFE1` remains the right default path for `UM25C` / `UM34C`
- for UI, wording, and software workflow clues, the imported APKs may be useful even if the desktop package stays `UM24C`-centric
