supply.h File Reference

A programmable supply: what it can be set to, what it was set to, and what it delivers. More...

#include <stdbool.h>
#include <stdint.h>

Go to the source code of this file.

Data Structures
struct	supply_caps_t
	What a supply can be set to. More...
struct	supply_state_t
	A supply's readings, set points, mode and trip state. More...
struct	supply_limits_t
	What the operator allows, on top of what the supply can do: caps on the set points, and trips that switch the output off. More...
struct	supply_trip_t
	How long each reading has been over its threshold, counted from the first reading seen over it, for the trips. More...
struct	supply_sim_t
	The state of the supply model. More...

Macros
#define	SUPPLY_CAPS_PPS_DEFAULT   { 3.3f, 21.0f, 0.02f, 0.5f, 5.0f, 0.05f }
	The range a USB-PD PPS (Programmable Power Supply) source offers in its widest profile, 3.3 to 21V in 20mV steps and up to 5A in 50mA steps.
#define	SUPPLY_OK_VOLTAGE   0x01u
	Which readings arrived; an absent one is drawn and logged empty.
#define	SUPPLY_OK_CURRENT   0x02u
#define	SUPPLY_SIM_LOAD_OHMS   6.0f
	A supply feeding a servo-like load, for the panel to run while no driver exists, and for the screenshots.
#define	SUPPLY_SIM_PERIOD_S   3.0f
#define	SUPPLY_SIM_BURST_S   0.6f
#define	SUPPLY_SIM_BURST_A   1.4f
#define	SUPPLY_SIM_SOURCE_OHMS   0.05f

Enumerations
enum	supply_mode_t { SUPPLY_MODE_OFF = 0 , SUPPLY_MODE_CV , SUPPLY_MODE_CC }
	The output mode of a supply: off, constant voltage or constant current. More...
enum	supply_trip_kind_t { SUPPLY_TRIP_NONE = 0 , SUPPLY_TRIP_CURRENT , SUPPLY_TRIP_VOLTAGE }
	The trips: none, current and voltage.

Functions
supply_caps_t	supply_caps_limited (const supply_caps_t *caps, const supply_limits_t *lim)
	The supply's caps narrowed by lim: the set points a screen offers.
void	supply_trip_reset (supply_trip_t *t)
	Clears the trip state.
supply_trip_kind_t	supply_trip_step (supply_trip_t *t, const supply_limits_t *lim, const supply_state_t *s, float dt_s)
	Take dt_s of the readings in s into the trips.
float	supply_snap (float value, float min, float max, float step)
	value clamped to min .. max and rounded to a multiple of step above min.
void	supply_reset_peaks (supply_state_t *s)
	The run's extremes start again from what is shown, and only from readings that arrived; a maximum with nothing under it starts at 0.
void	supply_track_peaks (supply_state_t *s)
	Take this sample into the run's extremes, only what arrived.
void	supply_reset_totals (supply_state_t *s)
	The run begins: nothing delivered, nothing counted.
void	supply_count_totals (supply_state_t *s, float dt_s)
	Add dt_s of the readings to the run's charge and energy while the output is on, only what arrived; dt_s is clamped to 0 ..
void	supply_sim_init (supply_sim_t *m)
	Sets up the supply model.
void	supply_sim_set (supply_sim_t *m, float v, float i)
	Set points are snapped to the caps; the output's state is kept.
void	supply_sim_output (supply_sim_t *m, bool on)
	Switches the model's output on or off.
void	supply_sim_step (supply_sim_t *m, float dt_s, supply_state_t *out)
	Advance dt_s and write the readings, mode and set points into out, counting one more sample; peaks, totals and taken_ms are the caller's.

Detailed Description

A programmable supply: what it can be set to, what it was set to, and what it delivers.

The SUPPLY screen and the log see this and never the supply's own wire, so the same screen runs on the panel's model now and on a driver for the PD mini (a USB Power Delivery trigger controlled over a UART) once its protocol is known. Which board talks to it is not decided either; this struct is what crosses whichever boundary that turns out to be.

Pure C, no ESP-IDF (Espressif Internet-of-Things Development Framework).

SPDX-License-Identifier: MIT

Macro Definition Documentation

SUPPLY_CAPS_PPS_DEFAULT

#define SUPPLY_CAPS_PPS_DEFAULT   { 3.3f, 21.0f, 0.02f, 0.5f, 5.0f, 0.05f }

The range a USB-PD PPS (Programmable Power Supply) source offers in its widest profile, 3.3 to 21V in 20mV steps and up to 5A in 50mA steps.

The panel's model uses it until a PD mini driver reports what that board and the source behind it can do; a fixed-voltage PD source offers far less.

SUPPLY_SIM_LOAD_OHMS

#define SUPPLY_SIM_LOAD_OHMS   6.0f

A supply feeding a servo-like load, for the panel to run while no driver exists, and for the screenshots.

The load is a resistance with a burst on top: LOAD_OHMS at rest, and every SUPPLY_SIM_PERIOD_S a burst of SUPPLY_SIM_BURST_A for SUPPLY_SIM_BURST_S, which is what a servo moving under load draws. When the load would draw more than the limit the model holds the limit and the voltage falls with it (CC); otherwise it holds the set voltage less a 0.05ohm source resistance (CV). Deterministic, so a screenshot is the same every time.

Enumeration Type Documentation

supply_mode_t

enum supply_mode_t

The output mode of a supply: off, constant voltage or constant current.

Enumerator
SUPPLY_MODE_OFF	output switched off
SUPPLY_MODE_CV	regulating its voltage
SUPPLY_MODE_CC	holding its current limit

Function Documentation

supply_caps_limited()

supply_caps_t supply_caps_limited	(	const supply_caps_t *	caps,
		const supply_limits_t *	lim )

The supply's caps narrowed by lim: the set points a screen offers.

A cap below the supply's own minimum leaves the range at that minimum.

Parameters

caps	The supply's caps.
lim	The limits to narrow by.

Returns

The caps narrowed by lim.

supply_count_totals()

void supply_count_totals	(	supply_state_t *	s,
		float	dt_s )

Add dt_s of the readings to the run's charge and energy while the output is on, only what arrived; dt_s is clamped to 0 ..

1s, as the bench's totals are.

Parameters

s	The supply state.
dt_s	The time since the last call, in s.

supply_reset_peaks()

void supply_reset_peaks

(

supply_state_t *

s

)

The run's extremes start again from what is shown, and only from readings that arrived; a maximum with nothing under it starts at 0.

The minimum voltage is a reading only while the output is on: an output switched off reads 0V, and a floor of 0V reads as a collapsed rail.

Parameters

s	The supply state.

supply_reset_totals()

void supply_reset_totals

(

supply_state_t *

s

)

The run begins: nothing delivered, nothing counted.

Parameters

s	The supply state.

supply_sim_init()

void supply_sim_init

(

supply_sim_t *

m

)

Sets up the supply model.

Parameters

m	The model to set up.

supply_sim_output()

void supply_sim_output	(	supply_sim_t *	m,
		bool	on )

Switches the model's output on or off.

Parameters

m	The model.
on	true to switch the output on.

supply_sim_set()

void supply_sim_set	(	supply_sim_t *	m,
		float	v,
		float	i )

Set points are snapped to the caps; the output's state is kept.

Parameters

m	The model.
v	The set point voltage, in V.
i	The set point current, in A.

supply_sim_step()

void supply_sim_step	(	supply_sim_t *	m,
		float	dt_s,
		supply_state_t *	out )

Advance dt_s and write the readings, mode and set points into out, counting one more sample; peaks, totals and taken_ms are the caller's.

Parameters

m	The model.
dt_s	The time step, in s.
out	Receives the readings, mode and set points.

supply_snap()

float supply_snap	(	float	value,
		float	min,
		float	max,
		float	step )

value clamped to min .. max and rounded to a multiple of step above min.

A step of 0 or less only clamps.

Parameters

value	The value to snap.
min	The lowest value.
max	The highest value.
step	The step above min, in the value's unit; 0 or less only clamps.

Returns

The value clamped to min .. max and snapped to a step.

supply_track_peaks()

void supply_track_peaks

(

supply_state_t *

s

)

Take this sample into the run's extremes, only what arrived.

Parameters

s	The supply state.

supply_trip_reset()

void supply_trip_reset

(

supply_trip_t *

t

)

Clears the trip state.

Parameters

t	The trip state.

supply_trip_step()

supply_trip_kind_t supply_trip_step	(	supply_trip_t *	t,
		const supply_limits_t *	lim,
		const supply_state_t *	s,
		float	dt_s )

Take dt_s of the readings in s into the trips.

The count starts at the first reading seen over a threshold, and each reading over it after that adds the time since the one before; one at or under it starts the count again, and one that did not arrive leaves it where it is. A trip that is off forgets its count, and so does one whose threshold changed. A trip time of 0 fires on the first reading over. Returns which trip fired, once the time over reaches lim->trip_s; nothing while the output is off. dt_s is clamped to 0 .. 1s, as the totals' steps are.

Parameters

t	The trip state.
lim	The trip limits.
s	The readings.
dt_s	The time since the last call, in s.

Returns

The trip that fired.