sfm Namespace Reference

Namespaces
namespace	addr
	7-bit I2C addresses (data sheet §4.1 / ADDR pin strapping on SFM4300).
namespace	cmd
	16-bit command codes (data sheet §4.3, Tables 3–12).
namespace	timing
	Timing (data sheet §2.4 / §4.3).

Classes
class	Driver
	SF06 flow-meter client. More...
struct	DriverResult
struct	DriverResult< void >
class	I2cInterface
	CRTP base for the SF06 I2C transport. More...
struct	Measurement
	One continuous-mode sample (data sheet §4.3.1 read frame). More...
struct	ProductInfo
	Product identifier + 8-byte serial number (data sheet §4.3.9). More...
struct	Scaling
	Scale factor / offset / unit for one gas lookup table (data sheet §4.3.6). More...
struct	StatusWord
	Decoded status word (data sheet §4.3.2, Table 5). More...

Enumerations
enum class	DriverError : uint8_t {   None = 0 , InvalidParameter , NotInitialized , BusWrite ,   BusRead , NoData , Crc , UnsupportedGas ,   NotSupported , UnexpectedUnit , VariantUnknown }
	Driver-level error codes (stable for logging / telemetry). More...
enum class	Family : uint8_t { Sf06 = 0 , Sfx6000 }
	Part family: decides command meaning, frame layout and optional features. More...
enum class	Gas : uint8_t {   O2 = 0 , Air , N2O , CO2 ,   AirO2Mix , N2OO2Mix , CO2O2Mix , Ar ,   HeOx , HeOxO2Mix }
	Calibrated gas / gas-mixture lookup table selector (family-neutral). More...
enum class	Variant : uint8_t {   Unknown = 0 , Sfm4300_20_B , Sfm4300_20_O , Sfm4300_20_P ,   Sfm4300_50_B , Sfm4300_50_O , Sfm4300_50_P , Sfm6000D_50 ,   Sfm6000D_20 , Sfm6000D_5 , Sfm3003_300_CL , Sfm3003_300_CE ,   Sfm3013_300_CL , Sfm3013_300_CLM , Sfm3019_240 , Sfm3119_240_CL }
	Part variant decoded from the product identifier. More...

Functions
const char *	GetDriverVersion () noexcept
	Driver version string (from generated sfm_version.h).
constexpr uint8_t	Crc8 (const uint8_t *data, std::size_t len) noexcept
	CRC-8 per Sensirion SF06 (poly 0x31, init 0xFF, no reflection/xorout).
constexpr uint8_t	Crc8Word (uint16_t word) noexcept
	CRC-8 of one big-endian 16-bit word.
constexpr std::string_view	ToString (DriverError e) noexcept
constexpr std::string_view	ToString (Family f) noexcept
constexpr std::string_view	ToString (Gas g) noexcept
constexpr uint16_t	StartCommandFor (Family family, Gas g) noexcept
	Start-measurement command code for g on family.
constexpr bool	IsMixture (Gas g) noexcept
constexpr std::string_view	ToString (Variant v) noexcept
constexpr Family	FamilyOf (Variant v) noexcept
	Family of a known variant (Sf06 for Unknown — the caller's assumption).
constexpr Variant	VariantFromProductId (uint32_t product_id) noexcept
	Decode a 32-bit product identifier.
constexpr float	FullScaleSlm (Variant v) noexcept
	Full-scale Air / O2 flow [slm] for a known variant (0 when unknown).
constexpr bool	SupportsGas (Variant v, Gas g) noexcept
	Whether a variant carries a factory calibration for g.
constexpr bool	GasNeedsKnownFamily (Gas g) noexcept
	True when g's start code differs between families (needs a known variant).
constexpr bool	StatusNibbleIsKnown (Family family, uint8_t nibble) noexcept
	Whether nibble (status bits 15:12) names a start command of family.
constexpr Gas	GasFromStatusNibble (Family family, uint8_t nibble) noexcept
	Map the status command nibble back onto a gas selector (per family).
constexpr Gas	GasFromStatusNibble (Variant variant, uint8_t nibble) noexcept
	Variant-aware status decode: as the family overload, except that on the SFM3013-300-CLM nibble 2 is HeOx and 7 is HeOx/O2.

Variables
constexpr uint16_t	kFlowUnitSlm20C = 0x0148
	Fixed flow-unit code returned by the SFM4300 (slm at 20 °C, 1013.25 mbar).
constexpr float	kTemperatureScalePerC = 200.0f
	Temperature scale (data sheet Tables 15/16: scale 200 per °C, offset 0).
constexpr uint16_t	kStatusPureGasFraction = 0x3FF
	Status-word gas fraction value for a pure calibration gas (bits 9:0).

Enumeration Type Documentation

DriverError

enum class sfm::DriverError : uint8_t

strong

Driver-level error codes (stable for logging / telemetry).

Enumerator
None
InvalidParameter	bad argument (e.g. averaging window > 128)
NotInitialized	transport EnsureInitialized() failed
BusWrite	command write NACKed / bus error
BusRead	command reply (identifier, scaling) NACKed / bus error
NoData	result-buffer read NACKed — no fresh sample yet / not measuring
Crc	CRC-8 mismatch on a received word.
UnsupportedGas	gas / mixture not calibrated on this variant
NotSupported	transport lacks the feature (e.g. general call)
UnexpectedUnit	scaling unusable: scale 0, or unit ≠ 0x0148 on a known SF06 part
VariantUnknown	gas needs a known part family (identity not read)

Family

enum class sfm::Family : uint8_t

strong

Part family: decides command meaning, frame layout and optional features.

Enumerator
Sf06	SFM4300, SFM3003/3013/3019/3119.
Sfx6000	SFM6000D (SFC6000D controllers share the interface)

Gas

enum class sfm::Gas : uint8_t

strong

Calibrated gas / gas-mixture lookup table selector (family-neutral).

Enumerator
O2	SF06 Gas 0 · SFx6000 Gas 0.
Air	SF06 Gas 1 · SFx6000 Gas 1.
N2O	SF06 Gas 2 (SFM4300-20 only) · SFx6000 Gas 3.
CO2	SF06 Gas 3 (SFM4300-20 only) · SFx6000 Gas 2.
AirO2Mix	O2 in Air — argument: O2 volume fraction (‰)
N2OO2Mix	SF06 mixture 1 — SFM4300-20 only.
CO2O2Mix	SF06 mixture 2 — SFM4300-20 only.
Ar	SFx6000 Gas 4 only.
HeOx	SF06 Gas 2 on SFM3013-300-CLM only: heliox 80/20 (code 0x3615)
HeOxO2Mix	SF06 mixture 1 on SFM3013-300-CLM only: O2 in HeOx (code 0x3639)

Variant

enum class sfm::Variant : uint8_t

strong

Part variant decoded from the product identifier.

SFM4300 data sheet Table 13; SFM3003 Table 13, SFM3013 Table 13, SFM3019 Table 12, SFM3119 Table 12. New enumerators are appended, so stored values keep their meaning.

Enumerator
Unknown
Sfm4300_20_B	0x0403011x — 20 slm, basemount
Sfm4300_20_O	0x0403021x — 20 slm, O-rings
Sfm4300_20_P	0x0403031x — 20 slm, push-in fittings
Sfm4300_50_B	0x0403091x — 50 slm, basemount
Sfm4300_50_O	0x0403071x — 50 slm, O-rings
Sfm4300_50_P	0x0403061x — 50 slm, push-in fittings
Sfm6000D_50	0x060211xx — 50 slm (Air/O2; 20 slm CO2/N2O/Ar)
Sfm6000D_20	0x060212xx — 20 slm (Air/O2; 10 slm CO2/N2O/Ar)
Sfm6000D_5	0x060214xx — 5 slm (Air/O2; 2 slm CO2/N2O/Ar)
Sfm3003_300_CL	0x040201xx — −30…300 slm, address 0x28
Sfm3003_300_CE	0x040207xx — −150…300 slm, address 0x2D
Sfm3013_300_CL	0x040205xx — −30…300 slm, address 0x2F
Sfm3013_300_CLM	0x040202xx — −30…300 slm, also heliox, address 0x2F
Sfm3019_240	0x040206xx — −10…240 slm, address 0x2E
Sfm3119_240_CL	0x040401xx — −10…240 slm, address 0x29

Function Documentation

Crc8()

constexpr uint8_t sfm::Crc8 ( const uint8_t *  data, std::size_t  len  )

constexprnoexcept

CRC-8 per Sensirion SF06 (poly 0x31, init 0xFF, no reflection/xorout).

Crc8Word()

constexpr uint8_t sfm::Crc8Word ( uint16_t  word )

constexprnoexcept

CRC-8 of one big-endian 16-bit word.

FamilyOf()

constexpr Family sfm::FamilyOf ( Variant  v )

constexprnoexcept

Family of a known variant (Sf06 for Unknown — the caller's assumption).

FullScaleSlm()

constexpr float sfm::FullScaleSlm ( Variant  v )

constexprnoexcept

Full-scale Air / O2 flow [slm] for a known variant (0 when unknown).

GasFromStatusNibble() [1/2]

constexpr Gas sfm::GasFromStatusNibble ( Family  family, uint8_t  nibble  )

constexprnoexcept

Map the status command nibble back onto a gas selector (per family).

See StatusNibbleIsKnown() for the tables. A reserved or unknown nibble returns Gas::Air; check StatusNibbleIsKnown() first when that matters. On SFM3013-300-CLM, nibbles 2 and 7 are HeOx and HeOx/O2 (data sheet §4.3.1 Table 2): use the Variant overload.

GasFromStatusNibble() [2/2]

constexpr Gas sfm::GasFromStatusNibble ( Variant  variant, uint8_t  nibble  )

constexprnoexcept

Variant-aware status decode: as the family overload, except that on the SFM3013-300-CLM nibble 2 is HeOx and 7 is HeOx/O2.

GasNeedsKnownFamily()

constexpr bool sfm::GasNeedsKnownFamily ( Gas  g )

constexprnoexcept

True when g's start code differs between families (needs a known variant).

GetDriverVersion()

const char * sfm::GetDriverVersion ( )

inlinenoexcept

Driver version string (from generated sfm_version.h).

IsMixture()

constexpr bool sfm::IsMixture ( Gas  g )

constexprnoexcept

StartCommandFor()

constexpr uint16_t sfm::StartCommandFor ( Family  family, Gas  g  )

constexprnoexcept

Start-measurement command code for g on family.

Returns

0 when the family has no table for g.

Warning

The same code means different gases on the two families (0x3615 / 0x361E). Always pass the family the part reported.

StatusNibbleIsKnown()

constexpr bool sfm::StatusNibbleIsKnown ( Family  family, uint8_t  nibble  )

constexprnoexcept

Whether nibble (status bits 15:12) names a start command of family.

SF06 (SFM4300 data sheet §4.3.2 Table 5): the nibble is the index of the running command in the start-command table — 0 O2, 1 Air, 2 N2O, 3 CO2, 4 and 5 reserved (0x3624, 0x362F), 6 Air/O2, 7 N2O/O2, 8 CO2/O2. SFx6000: 0 to 4 pure gases, 0xA O2 in Air.

SupportsGas()

constexpr bool sfm::SupportsGas ( Variant  v, Gas  g  )

constexprnoexcept

Whether a variant carries a factory calibration for g.

SFM4300-50-x: O2, Air, Air/O2 mixture only (Table 16). SFM4300-20-x: the seven SF06 tables. SFM6000D-x: O2, Air, CO2, N2O, Ar and O2-in-Air. SFM3003 / SFM3013-300-CL / SFM3019 / SFM3119: O2, Air, Air/O2 (Table 2 of each data sheet); SFM3013-300-CLM adds HeOx and HeOx/O2. Unknown variants: O2 and Air only — every other start code means a different gas (or none) on the other family, so it is refused until the identity is read (see GasNeedsKnownFamily).

ToString() [1/4]

constexpr std::string_view sfm::ToString ( DriverError  e )

constexprnoexcept

ToString() [2/4]

constexpr std::string_view sfm::ToString ( Family  f )

constexprnoexcept

ToString() [3/4]

constexpr std::string_view sfm::ToString ( Gas  g )

constexprnoexcept

ToString() [4/4]

constexpr std::string_view sfm::ToString ( Variant  v )

constexprnoexcept

VariantFromProductId()

constexpr Variant sfm::VariantFromProductId ( uint32_t  product_id )

constexprnoexcept

Decode a 32-bit product identifier.

SF06: low nibble = revision. SFx6000: low byte = revision (subject to change while the parts are preliminary).

Variable Documentation

kFlowUnitSlm20C

constexpr uint16_t sfm::kFlowUnitSlm20C = 0x0148

constexpr

Fixed flow-unit code returned by the SFM4300 (slm at 20 °C, 1013.25 mbar).

kStatusPureGasFraction

constexpr uint16_t sfm::kStatusPureGasFraction = 0x3FF

constexpr

Status-word gas fraction value for a pure calibration gas (bits 9:0).

kTemperatureScalePerC

constexpr float sfm::kTemperatureScalePerC = 200.0f

constexpr

Temperature scale (data sheet Tables 15/16: scale 200 per °C, offset 0).