kha

Overengineered Modular RS-485 Multi-Master 19" Subrack Home Control

Repository

^{Hint: "bgt" is German for Baugruppenträger translating to subrack assembly}

• datasheets: Datasheets of used components and rack dimensions / layouts
• kha-bgt-misc: Generic subrack modules
• kha-bgt-rack: 19" rack assembly
• kha-bgt-subrack: Subrack modules
• kha-boot.X: Bootloader used by all devices (main.c)
• kha-common.X: Protocol stack used by all devices (kha-stack.c / kha-stack.h / kha-constants.h)
• kha-nodes: Bus nodes
• superseded: Superseded ideas and failed hardware revisions
• tools: Helper scripts to e.g. generate userrow data
• kha-bom-collection.pdf / .ods: Not exactly a Bill-of-Materials rather a collection of most components used
• kha-protocol.pdf / .ods: Protocol stack definitions

Videos

Two hour deep dive lecture style video on youtube: https://youtu.be/BUSnTUGKZzc

Photos

Misc

• All PCBs use eAVR as connector for AVR flashing
• It all started simple with lightdesk

Todo

• Node: LED marquee node
• Node: IrDA bridge (bridging the bus through a window)
• Stack: Combine queued TX commands into single burst?
• Stack: Merge similiar queued TX commands into single command?
• Stack: Process TX commands as incoming RX commands?

Regrets

• Terrible collision detection / avoidance
• Buck converter capacitor generates audible noise

License

This project is licensed under the Creative Commons Attribution-NonCommercial 3.0 Unported (CC BY-NC 3.0) license.