Components::LoadSwitch

Overview

The LoadSwitch component is an active F' component that controls a single load switch output through the gpioSet output port (connected to the platform's GPIO driver). It exposes two async commands to turn the switch on and off, telemetry reporting the current state. It also provides ports to control the switch and notify other components of state changes.

Responsibility

• Control the power rail for a connected peripheral by asserting/deasserting a GPIO.
• Report state changes via an event and telemetry channel.
• Provide an interface for other components to control the switch and subscribe to state changes.

Class Diagram

classDiagram
    namespace Components {
        class LoadSwitchComponentBase {
            <<Auto-generated>>
        }
        class LoadSwitch {
            + LoadSwitch(const char* compName)
            + ~LoadSwitch()
            - TURN_ON_cmdHandler(FwOpcodeType opCode, U32 cmdSeq): void
            - TURN_OFF_cmdHandler(FwOpcodeType opCode, U32 cmdSeq): void
            - turnOn_handler(FwIndexType portNum): void
            - turnOff_handler(FwIndexType portNum): void
        }
    }
    LoadSwitchComponentBase <|-- LoadSwitch : inherits

External interface

Commands

Name	Description	Implementation notes
TURN_ON	Turn on the associated power rail	TURN_ON_cmdHandler sets the gpio via gpioSet_out(0, Fw::Logic::HIGH), emits StatusChanged (ON), updates IsOn telemetry, replies OK.
TURN_OFF	Turn off the associated power rail	TURN_OFF_cmdHandler sets the gpio via gpioSet_out(0, Fw::Logic::LOW), emits StatusChanged (OFF), updates IsOn telemetry, replies OK.

Telemetry

Name	Type	Description
IsOn	Fw.On	Current power state; written after commands. Note: Reports ON only after a stabilization delay (default 1s) following the turn-on command.

Events

Name	Severity	ID	Format
StatusChanged	activity high	1	"Load switch state changed to {}"

The component logs the StatusChanged event whenever the switch transitions due to a command.

Ports

Port name	Direction	Port type	Notes
gpioSet	output	Drv.GpioWrite	Used to write the physical GPIO. Implementation always uses index 0 (gpioSet_out(0, ...)).
gpioGet	output	Drv.GpioRead	Used to read the physical GPIO state.
turnOn	input (sync)	Fw.Signal	Turns on the load switch.
turnOff	input (sync)	Fw.Signal	Turns off the load switch.
loadSwitchStateChanged	output	loadSwitchStateChanged	Notifies connected components when the load switch state changes

Requirements

Name	Description	Validation
Control via Command	The component shall allow turning the load switch on and off via ground commands TURN_ON and TURN_OFF.	Integration test
Control via Port	The component shall allow turning the load switch on and off via input ports turnOn and turnOff.	Verify turnOn and turnOff port calls change the GPIO state and telemetry.
State Telemetry	The component shall report the current state of the load switch via the IsOn telemetry channel.	Integration test
State Event	The component shall emit a StatusChanged event when the load switch state changes.	Verify StatusChanged event is emitted upon state transitions.
State Notification	The component shall notify connected components of state changes via the loadSwitchStateChanged port.	Downstream component testing
GPIO Control	The component shall control the physical GPIO pin corresponding to the load switch using the gpioSet port.	Downstream component testing

Change Log

Date	Description
10-22-2025	Sarah, Kevin, and MoMata's first commit
11-07-2025	Updated SDD to match implementation in LoadSwitch.cpp/.hpp/.fpp (commands, telemetry, event, ports, reset behavior).
11-30-2025	Removed Reset capability. Added loadSwitchStateChanged output port for state notifications.