The Krake, An Alarm Annunciator designed for easy integration into systems needing to bring to the attention of humans some condition. Can be used by professional system integrators and hobbyists.
This ?150? x ?180? x ?67? mm device has a speaker, a 20x4 character display, five white LEDs. It is a peripheral which can be controlled over a WiFi network using MQTT interface, a wired RS232 interface or a wired SPI interface with fully customiseable audio visual capabilitites.
- A condition is detected by an external sensor that relays this information to Krake to trigger and alarm event. Such as a pressure sensor detecting the opening of a gate.
- The Krake receives the information about the event wirelessly via MQTT over local network or internet. A gate open sensor on a security system would publish a message to the Krake via MQTT or direct RS232 connection
- The Krake alerts you of this event- Lights flash, audio plays and the message is displayed on an LCD for the user
- The user is able to react to the alarm with {acknowledgement, dismissal, shelving or completion}, A mute button allows the user to temporarily mute the audio to prevent alarm fatigue.
- Quick Start
- About Krake
- Example Use Cases
- Features
- Hardware
- Firmware
- Roadmap
- Contributing
- Credits & Mentorship
- Trust & Credentials
- References & Further Reading
Once upon a time, we (Robert, Nagham and Lee) had envisioned that upon receiving a Krake the user would practice working with it by using the MQTT web page to publish messages to their device.
Purchasable from https://www.pubinv.org/shop/
User manuals & test and assembly procedure can be found in the references and further reading section
Planned LCD Layout:
Q:+ NEXT W B M ⚙
CRIT Pump Failure
ID:123 Temp High
Ack Dismiss Shelve
Rotary Encoder:
Rotate: Navigate alarms or menu entries
Short Press: Select item
Long Press: Open Settings Menu
Alarm Actions:
Rotatary encoder to enter action selection
Acknowledge, Dismiss or Shelve
Settings Menu:
The local settings menu includes:
* Volume Level
* Mute Duration
* COM Setup
* Device Reset
* Exit Menu
To build your own please see instructions for testing and assembly of Krake hardware: Krake Test and Assembly Procedure Document
The hope was to develop the initial design for a wireless alarm device to alert nearby parties of a particular state. About the name, Krake, the inspiration for the invention name is based on a Crake: a bird with a distinctive, slightly alarming cry. We changed the spelling so as to have a unique name and still preserve the humor.
Care at home: Alert an elderly person living alone to a fall or blood pressure drop — giving family peace of mind from anywhere.
Medical Equipment: For ventilators and critical devices, Krake provides a dedicated alarm channel for life-threatening mechanical failures.
IT Infrastructure: Alert on-site staff instantly when a server overheats, a UPS fails, or network connectivity drops — a physical alarm that doesn't rely on the very infrastructure it's monitoring.
| Feature | Details |
|---|---|
| Customiseable audio | WAV and MP3 playback, Alarm-level-specific audio, Adjustable volume,SD-card-based audio storage, Busy-line monitoring and Runtime diagnostics |
| LCD User Interface & Rotary Knob | 20 x 4 I²C LCD interface integrated with a rotary encoder and custom menu system to navigate settings without the need for an external device. Real-time alarm display, Wi-Fi status indication, MQTT broker status indication, Volume and mute display and Alarm acknowledgement actions |
| LED Annunciation | Variety of LED levels including steady or blinking deisgned to be visible across a room |
| Flexible Power | USB-C, 2.1mm center-positive barrel connector or RJ12 SPI interface power jumpers |
| Wi-Fi Connectivity | Acts as a Wi-Fi station connected to a local network enabling alerts locally or via internet, captive portal set up, storage of multiple Wi-Fi credentials, automatic reconnection, OTA firmware updates and Network status display |
| MQTT Protocol | MQTT alarm subscriptions, GPAP response publishing, Alarm acknowledgements, Alarm dismissal and shelving, Device monitoring, Configurable topic subscriptions and MQTT status display on LCD |
| Mute Button & time out handling | Configurable mute timeout, Automatic unmute, Manual mute override and LCD mute indication |
| HL7 Compatible | Designed to work with medical data standards |
| Fully Open Source | AGPL firmware, CERN OHL Hardware |
| Persistent COM configuration | Interfaces to external controllers through a DB9 Female RS-232 DCE connection. Configurable baud rate (1200,2400,4800, 9600, 19200, 38400, 57600, 115200), RTS/CTS hardware flow control and LCD-based configuration menu |
| Speaker | 3 inch 10W Full Range Round 8 ohm Speaker with FR:12-16KHz |
| GPAP message parsing | Alarm message are structured, message type, severity digit (0-5), optional message id, optional alarm type deisgnator and optional content up to 80 characters |
| SPI alarm input support | ALlows processing of alert signals communicated or wired through SPI data lines to recognise fault or warning flags in connected sensors |
| Krake™ rev2 | Krake™ rev1 |
|---|---|
|
 |
| 3 inch 10W Full Range Round 8 ohm Speaker with FR:12-16KHz. | 28mm Speaker |
| dimensions | dimensions |
| functionality? | functionality? |
- Advanced alarm queue management
- Enhanced LCD UI animations and icons
- Bluetooth and BLE alarm forwarding
- Mesh networking support
- Remote firmware fleet management
- Local event history logging
- Expanded GPAP/HL7 interoperability
- Power optimization modes
- Alarm escalation workflows
Krake Workflow Contribution Procedure
The Krake has been developed primarily by volunteer engineer Nagham Kheir, with mentorship and oversight from volunteer Inventional Coach Lee Erickson and a group of volunteers from around the globe.
Mentorship and Teamwork: The Story of the Krake
Nagham Kheir: Invention Coach
Forrest Lee Erickson: Invention Coach
Robert L. Read: Invention Coach
Yehia Shalaby: Public Inventor
Courtney Ludick: Public Inventor
Yukti: Public Inventor
Juhandre Knoetze: Public Inventor
Krake hardware has been certified by the Open Source Hardware Association (OSHWA): OSHWA certification listing: OSHWA Certification Directory
Certification UID: US002818
Website: https://pubinv.github.io/krake/
Brochure: Copy of Krake Brochure.pdf
Logo: 
Krake Repo: https://github.com/PubInv/krake
Wiki: https://github.com/PubInv/krake/wiki
HardwareX Article: HardwareX Article
User Manual: draft user manual
Developers Manual: draft developers manual.
OSHWA certification listing: OSHWA Certification Directory
The team behind Krake: Mentorship and Teamwork: The Story of the Krake
Krake workflow: Krake Workflow Contribution Procedure
Build your own: Krake Test and Assembly Procedure Document
Database for Krake units and test registries: Krake Factory Inventory
Global Open Source Quality Assuring System:Asset History Records Public Invention Krake Rev. 2
GPAP: https://github.com/PubInv/gpap
- Github repo: https://github.com/PubInv
- Website: https://www.pubinv.org/
- Products page: https://www.pubinv.org/shop/
Firmware: GNU Affero GPL 3.0
Hardware: CERN Open Hardware Licence Version 2 - Strongly Reciprocal
Krake™ is a trademark of Public Invention.