74 lines
1.6 KiB
Markdown
74 lines
1.6 KiB
Markdown
# Design Decisions
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## Components
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### npm1300
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- Two bucks 1.8V and 3.3V
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- Hopefully nice ONOFF logic possible
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https://chatgpt.com/share/693174fd-35cc-8007-8e88-06d77bcb8abc
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```mermaid
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stateDiagram-v2
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[*] --> OFF_HIBERNATE
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OFF_HIBERNATE --> ON_BATTERY : SHPHLD ≥ tshipToActive
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note right of ON_BATTERY
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Condition: VBUS not present
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end note
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OFF_HIBERNATE --> CHARGING_ONLY : USB plugged in
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note right of CHARGING_ONLY
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Condition: VBUS > VBUSPOR
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end note
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ON_BATTERY --> OFF_HIBERNATE : Short press SHPHLD
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note right of OFF_HIBERNATE
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FW calls TASKENTERHIBERNATE
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Condition: VBUS not present
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end note
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ON_BATTERY --> CHARGING_ON : USB plugged in while ON
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CHARGING_ON --> CHARGING_ONLY : Short press SHPHLD (SW-Off)
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CHARGING_ONLY --> CHARGING_ON : Short press SHPHLD (SW-On)
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CHARGING_ON --> ON_BATTERY : VBUS removed AND SW=ON
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CHARGING_ONLY --> OFF_HIBERNATE : VBUS removed AND SW=OFF
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note right of OFF_HIBERNATE
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FW calls TASKENTERHIBERNATE
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end note
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```
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**Conclusion**: Should work by attaching one button.
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### TRS Jack
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- Detection
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- Mono vs Stereo (Telecoil vs Headsets)
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- Goal: Mono and Stereo 'just works'
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https://chatgpt.com/share/69316f49-fc30-8007-8096-5d91e9cd69a5
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TLV supports short circuit detection and powers down the output.
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TLV supports headphone detection (no headphone, stereo, stereo with mic).
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**Conclusion**: The TLV can handle everything we need to do to support both mono (telecoil) and stereo.
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## Schematic
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## Board
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