diff --git a/docs/temperature-sensor.md b/docs/temperature-sensor.md
index 05af4ef..fc71a46 100644
--- a/docs/temperature-sensor.md
+++ b/docs/temperature-sensor.md
@@ -76,15 +76,26 @@ Temperature value = 0x131, converted to decimal 305, actual temperature value =
#### The host reads the humidity command frame (0x04):
+> [!WARNING]
+> **Both frames in this humidity section had wrong check bytes in the source we transcribed from,
+> and both have been corrected below.** The request was printed as `0xC1 0xCA` but `01 04 00 02 00
+> 01` checksums to `0x90 0x0A`; the response was printed as `0xD1 0xBA` but `01 04 02 02 22`
+> checksums to `0x38 0x49`.
+>
+> Every other frame in this file is correct, as is every frame in the relay manual. They were all
+> checked against the CRC implementation in
+> [serial/src/modbus/crc.ts](../serial/src/modbus/crc.ts) by `serial/src/modbus/crc.test.ts`, which
+> is where the mistake surfaced. Do not "fix" these back without recomputing them.
+
| Slave address | function code | Register address High byte | Register address Low byte | Number of registers High byte | Number of registers Low byte | CRC High byte | CRC Low byte |
| ------------- | ------------- | -------------------------- | ------------------------- | ----------------------------- | ---------------------------- | ------------- | ------------ |
-| 0x01 | 0x04 | 0x00 | 0x02 | 0x00 | 0x01 | 0xC1 | 0xCA |
+| 0x01 | 0x04 | 0x00 | 0x02 | 0x00 | 0x01 | 0x90 | 0x0A |
#### The slave responds to the data frame:
| Slave address | function code | Number of bytes | humidity High byte | humidity Low byte | CRC High byte | CRC Low byte |
| ------------- | ------------- | --------------- | ------------------ | ----------------- | ------------- | ------------ |
-| 0x01 | 0x04 | 0x02 | 0x02 | 0x22 | 0xD1 | 0xBA |
+| 0x01 | 0x04 | 0x02 | 0x02 | 0x22 | 0x38 | 0x49 |
Humidity value=0x222, converted to decimal 546, actual humidity value=546 / 10 = 54.6%;
diff --git a/serial/.vscode/extensions.json b/serial/.vscode/extensions.json
index bdef820..1b39e50 100644
--- a/serial/.vscode/extensions.json
+++ b/serial/.vscode/extensions.json
@@ -1,3 +1,3 @@
{
- "recommendations": ["svelte.svelte-vscode"]
+ "recommendations": ["solidjs-community.solid-snippets", "vitest.explorer"]
}
diff --git a/serial/README.md b/serial/README.md
index ceeb933..efffbe8 100644
--- a/serial/README.md
+++ b/serial/README.md
@@ -1,38 +1,47 @@
# serial
-A browser tool for talking to the RS-485/Modbus RTU devices on this project's bus, using the
-[Web Serial API](https://developer.mozilla.org/en-US/docs/Web/API/Web_Serial_API). It opens a USB
-serial adapter straight from the page, reads input registers and reads *and writes* holding
-registers — which is how a device gets configured before it is wired into the fan controller.
+A browser tool for the RS-485/Modbus RTU bus this project's devices sit on, using the
+[Web Serial API](https://developer.mozilla.org/en-US/docs/Web/API/Web_Serial_API). It does two
+things a firmware build cannot:
-It was folded in from [SantaClaas/serial](https://github.com/SantaClaas/serial), where it lived as
-its own repository.
+- **Watches the bus.** Decodes the traffic between the fan controller and the fans without joining
+ in, the way [debug-listener](../debug-listener) does from the desktop — but framed and decoded
+ rather than printed as bytes.
+- **Talks to a device directly.** Reads input registers and reads *and writes* holding registers,
+ which is how a device gets its address, baud rate and correction values set before it is wired in.
+
+Only one of those at a time per port: watching is passive and polling is not, and a half-duplex
+RS-485 line has room for one master.
## Running it
```bash
-cd serial && npm install && npm run dev
+cd serial && pnpm install && pnpm dev
```
+`pnpm test` runs the protocol tests, `pnpm check` type-checks, `pnpm build` does both and produces
+`dist/`.
+
The Web Serial API is Chromium-only (Chrome, Edge, Opera) and needs a secure context, so `localhost`
-or HTTPS. The app says so itself when the API is missing rather than failing silently.
+or HTTPS. The app says so itself rather than failing silently.
+
+## Layout
-`npm run check` type-checks the Svelte components.
+| Path | What it is |
+|---|---|
+| `src/modbus/crc.ts` | The CRC-16 every RTU frame ends with. The one little-endian field in the protocol. |
+| `src/modbus/pdu.ts` | Frame lengths, decoding and building, per function code. |
+| `src/modbus/monitor.ts` | Recovering frames from a bus you are not driving. |
+| `src/modbus/frames.fixture.ts` | Frames copied out of the device manuals, CRCs and all. |
-## What it does today
+Everything under `src/modbus` is plain TypeScript over bytes with no DOM in it, so it is tested
+directly with `vitest`. The tests are built on frames the *manufacturers* printed, which is the
+strongest check available: they agree only if this code agrees with the devices rather than merely
+with itself.
-- **Add Port** calls `navigator.serial.requestPort()` filtered to USB vendor `0x1A86` / product
- `0x7523` — the CH340 adapter. That filter is hardcoded in `src/lib/SerialPortsList.svelte`, so a
- different adapter will not show up in the picker.
-- Baud rate and parity are chosen per port before opening it. The RadiCal fans want 19 200 baud with
- **even** parity; the temperature sensor defaults to 9600 with **no** parity. A port can only speak
- one of those at a time.
-- Devices are added to an open port by Modbus address. Each device type declares its registers
- once — address, length, how to decode the bytes, and for holding registers how to encode and
- validate them — and the UI is generated from that declaration
- (`src/lib/modbus.ts`, `src/lib/devices/`).
-- Two device types are implemented: the ebm-papst RadiCal fan (`devices/fan.ts`) and the temperature
- sensor (`devices/temperatureSensor.ts`).
+> That is not hypothetical. The humidity frames in
+> [docs/temperature-sensor.md](../docs/temperature-sensor.md) had wrong check bytes, and the test
+> comparing them against `crc.ts` is what found it. Both are corrected there now.
## Where the device documentation lives
@@ -42,18 +51,14 @@ or HTTPS. The app says so itself when the API is missing rather than failing sil
- **Temperature sensor** — [docs/temperature-sensor.md](../docs/temperature-sensor.md). No
manufacturer PDF exists for it; that file is all there is.
-The register names in `devices/fan.ts` are working translations of the German manual made before
-that manual was checked in, and several are flagged as guesses in the source (`PhaseControlFactor`
-for *Aussteuergrad*, `CurrentDesiredEffect` for *Aktueller Wirksinn*). Prefer the terminology in the
-RadiCal documentation over these.
+The German terms in the RadiCal manual are the reference for what a register is called — *Aussteuergrad*,
+*Wirksinn*, *Sollwert* — rather than any translation invented here.
-## Status
+## Stack
-This is Svelte 4 on Vite 4 and is slated to be rewritten from scratch on SolidJS, adding passive
-listening of bus traffic in the manner of [debug-listener](../debug-listener). Treat the current
-code as reference for what the devices do, not as the shape the rewrite should take.
+SolidJS 2.0 (release candidate) on Vite, with pnpm. Solid 2.0 differs from 1.x in ways that matter
+when reading this code:
-The GitHub Pages deployment workflow that shipped with the standalone repository was dropped during
-the fold-in: GitHub only reads workflows from the repository root, so it would never have run from
-`serial/.github/`. It needs to be re-created at the repository root, scoped to this directory, when
-the rewrite is ready to deploy.
+- `createEffect` takes **two** functions, a compute and an effect: `createEffect(() => signal(), value => …)`.
+ The single-argument form from 1.x is gone and is typed `never`.
+- DOM rendering lives in `@solidjs/web`, not `solid-js/web`, and that is also the `jsxImportSource`.
diff --git a/serial/index.html b/serial/index.html
index 1de9aa6..1fc8d22 100644
--- a/serial/index.html
+++ b/serial/index.html
@@ -1,16 +1,13 @@
-
-
+
-
- Web Serial API
-
-
-
+
+ Modbus Serial Tool
+
+
-
-
-
-
\ No newline at end of file
+
+
+