modm API documentation
SI Units
using modm::frequency_t = uint32_t
using modm::baudrate_t = uint32_t
using modm::bitrate_t = uint32_t
using modm::percent_t = uint16_t
template<typename T >
constexpr frequency_t modm::Hz (T value)
template<typename T >
constexpr frequency_t modm::kHz (T value)
template<typename T >
constexpr frequency_t modm::MHz (T value)
template<typename T >
constexpr baudrate_t modm::Bd (T value)
template<typename T >
constexpr baudrate_t modm::kBd (T value)
template<typename T >
constexpr baudrate_t modm::MBd (T value)
template<typename T >
constexpr bitrate_t modm::bps (T value)
template<typename T >
constexpr bitrate_t modm::kbps (T value)
template<typename T >
constexpr bitrate_t modm::Mbps (T value)
template<typename T >
constexpr percent_t modm::pct (T value)
constexpr modm::literals::operator""_Hz (T value)
constexpr modm::literals::operator""_kHz (T value)
constexpr modm::literals::operator""_MHz (T value)
constexpr modm::literals::operator""_Bd (T value)
constexpr modm::literals::operator""_kBd (T value)
constexpr modm::literals::operator""_MBd (T value)
constexpr modm::literals::operator""_bps (T value)
constexpr modm::literals::operator""_kbps (T value)
constexpr modm::literals::operator""_Mbps (T value)
constexpr modm::literals::operator""_pct (T value)

Detailed Description

lbuild module: modm:math:units

modm uses a couple of common SI units for configuration of peripherals:

These are integral units, so 1 Hz/Bd/bps cannot be split further, and are cast directly to uint32_t type, so they can be used as a non-type template argument.

Conversion can be done via constexpr functions from any numerical type:

In addition, user-defined literals are provided in the modm::literals namespace:

using namespace modm::literals;
frequency_t frequency = modm::Mhz(10.5);
frequency = 10.5_MHz;
baudrate_t baudrate = 115.2_kBd;
baudrate = modm::kBd(115.2);
bitrate_t bitrate = modm::kbps(125);
bitrate = 125_kbps;
frequency = 4295_MHz; // OVERFLOW at 2^32 units!

Integral Percentages

Since float cannot be used as a non-type template argument, an integer type for providing tolerances in percent_t is available. Note that percent_t is implemented as an enum class, which prevents implicit conversions, since the base for this is not 1. You must therefore use the modm::pct(T value) or _pct constructors.

using namespace modm::literals;
percent_t tolerance = modm::pct(10);
tolerance = 10_pct;
// convert back to float. *internal use only*
float percent = modm::pct2f(tolerance);
This type is not guaranteed to hold more than 100 percent!