---
active: true
derived: false
header: 'Actuator Driver'
level: 1.3
normative: true
reviewed: null
links:
  - SWE-006
  - SWE-013
  - SWE-014
  - SWE-015
asil: B
---

# SWA-003: Actuator Driver

## Responsibility

Low-level control of the two actuator motors. PWM generation,
current measurement, overcurrent cutoff, clamping-force estimation.
Implemented in `src/actuator_driver.c`.

## Static view

```plantuml
@startuml
[Apply Controller] --> [Actuator Driver]
[Actuator Driver] --> [Hardware PWM] : pwm_set
[Actuator Driver] <-- [Hardware ADC] : current_sample
[Actuator Driver] --> [Diagnostic Manager] : DTC
@enduml
```

## Provided interfaces

```c
Status actuator_init(void);
void   actuator_apply(ActuatorId id, uint8_t pwm_percent);
void   actuator_release(ActuatorId id, uint8_t pwm_percent);
void   actuator_stop(ActuatorId id);
ActuatorStatus actuator_get_status(ActuatorId id);
void   actuator_isr_1khz(void); // Current sampling
```

## Resources

- Stack: <= 256 B
- Worst-case timing: 50 us per ISR
- Static RAM: 64 B per actuator

## Mapping to requirements

| Requirement | How covered |
|-------------|-------------|
| SWE-006 | actuator_release for both actuators in parallel |
| SWE-013 | actuator_isr_1khz |
| SWE-014 | overcurrent detector in ISR |
| SWE-015 | peak-current tracking + linear clamping-force estimate |