---
active: true
derived: false
header: 'HMI (switch, LED, display)'
level: 1.4
normative: true
reviewed: null
links:
  - SYS-008
  - SYS-010
asil: QM
---

# SA-004: HMI (switch, LED, display)

## Responsibility

Driver interaction and information: tap switch with integrated LED,
status display in the instrument cluster via CAN.

## Interfaces

| Element       | Type     | Behaviour                                 |
|---------------|----------|-------------------------------------------|
| Tap switch    | GPIO     | apply direction / release direction       |
| LED           | GPIO     | off / on / blink 2 Hz / blink 4 Hz        |
| Display       | CAN 0x3A0| 50 Hz status frame                        |