Configuration¶

Every setting the driver exposes, its default, and the module settings it leaves alone.

Constructor¶

fdo2::Driver<MyUart> sensor(uart);

Argument	Type	Meaning
`uart`	`MyUart&`	Your port; must outlive the driver. The UART must already be open at 19200 baud, 8N1

The constructor does not touch the UART. One driver per module; each module needs its own UART, because the protocol has no addresses.

Timeouts¶

Setting	Call	Default	Applies to
Measurement timeout	`SetMeasureTimeoutMs(uint32_t)`	250 ms	`MeasureMoxy()`, `MeasureMraw()`
Per-call measurement timeout	`MeasureMoxy(ms)`, `MeasureMraw(ms)`	0: use the setting above	That call only
Line timeout	`SetLineTimeoutMs(uint32_t)`	400 ms	`ReadVersion()`, `ReadUniqueId()`
Slow-command timeout	`SetSlowCommandTimeoutMs(uint32_t)`	12000 ms	`FlashLogo()`: the module echoes `#LOGO` only after the LED has flashed, about 1 s

Read them back with GetMeasureTimeoutMs(), GetLineTimeoutMs() and GetSlowCommandTimeoutMs(). The timeout is what the driver passes to your port's read(), so the port decides how precisely it is kept.

Constants¶

Constant	Value	Meaning
`fdo2::kFdo2G2DefaultBaud`	19200	The module's baud rate after every power-up
`fdo2::kFdo2G2PowerUpSettleMs`	1100	Wait after power-up before the first command (datasheet: about 1 s)

Module settings the driver does not change¶

These live in the module's flash and survive a power cycle. The driver reads with whatever is set; change them with a service tool, sparingly (about 20,000 flash cycles in the module's life).

Setting	Command	Factory value	Effect on the driver
Flash duration mode	`#SETM M`	M = 2: up to about 150 ms per measurement	M = 3 or 4: up to about 300 ms; raise the measurement timeout
Broadcast mode	`#BCST T`	Off	On: unsolicited `#MRAW` lines interleave with replies; turn it off
CRC	`#CRCE K`	Off	On: the driver verifies the `": C"` checksum of every reply; call `SetCrcRequired(true)` (UART protocol)
Calibration	`#CALO`, `#CAHI`	Factory calibration	None; a user calibration replaces the factory one
Baud rate	`#BAUD R`	19200, after every power-up	Your port must match it

Build options¶

Option or define	Default	Effect
`HF_FDO2_ENABLE_WARNINGS` (CMake)	`OFF`	`-Wall -Wextra -Wpedantic` on targets that link the driver
`HF_FDO2_BUILD_TESTS` (CMake)	`OFF`	Host unit tests and documentation snippets
`HF_FDO2_VERSION_*` (CMake)	`1.0.0`	Set in `cmake/hf_fdo2_build_settings.cmake`, written to `fdo2_version.h`

Next¶

API guide uses these settings in context; Installation shows the CMake setup.