Krake Test and Assembly Procedure Document
title: "Krake Test and Assembly Procedure Document" project: "Krake Project" document_type: "Test and Assembly procedure" document_id: "KRK-DOC-001" version: "v0.2.0" date: "2025-11-30" status: "Draft" authors:
- "Forrest Lee Erickson (BS of Science, Physics)"
- "Nagham Kheir (BE in Electric and Electronics, emphasis on Biomedical)"
- "Courtney Ludick (MEng Biomedical Engineering)"
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iso title page>>
Document Title: Krake Test and Assembly procedure Document
Project: Krake Project
Document Type: Test and Assembly procedure
Document ID: KRK-DOC-001
Version: v0.2.0
Date: 2027 - 02 - 08
Author(s): Forrest Lee Erickson BS of Science, Physics.
Nagham Kheir BE in Electric and Electronics emphasis on Biomedical
Courtney Ludick MEng Biomedical Engineering
Status: Draft
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| Version | Date | Author | Description |
|---|---|---|---|
| v0.1.0 | 2025-11-30 | Nagham Kheir | Initial draft |
| v0.2.0 | 2026-02-08 | Courtney Ludick | Added architecture diagram & additional information added |
| v1.0.0 | YYYY-MM-DD | [Author Name] | Finalized for publication |
Instructions to test the sub assembly units when received from the manufacturer. And instructions to add additional components to the sub assembly PCB_KRAKE_REV2.0 to build the final assembly of PWA and speaker into enclosure.
This document is written for a technician and describes the steps for testing and finishing the assembly of the Krake PWA (Printed Wiring Assembly) Rev 2.
This document describes how to take the sub assembly received from the contract manufacturer, and add the additional components (Mini MP3 player, SD card, LCD and the LEDs with their spacers) and electrical testing and functional testing. This document describes how to load factory test firmware and finaly product production firmware (the firmware the end user gets). This document also describes the final assembly of the PWA and a speaker into an enclosure. This document does not describe troubleshooting.
| Term | Definition |
|---|---|
| Krake | [Definition] |
| API | Application Programming Interface |
| DFP layer | A Mini MP3 player, DFP layer is by DF Robot, a more generic term is Mini MP3 Player. |
| ESD | Electro Static Discharge, damage caused by over voltage. |
| LCD | Liquid Crystal Display |
| PCB | Printed Circuit Board, typically a fiberglass panel with copper traces but to which electronic comments are NOT yet attached. |
| PWA | Printed Wiring Assembly, a PCB with components soldered / attached |
| Sketch | the Arduino vocabulary for source code file of the type used in the Arduino IDE and typically ending with the extension ".ino". |
| ... | ... |
This document was developed from the similar document of the GPAD (General Purpous Alarm Device) found at: https://github.com/PubInv/general-purpose-alarm-device/blob/main/Hardware/Documentation/ManufacturingUnitTestTroubleshootingRev2.md Additional notes from the Krake issue: ?TBD?
Detailed description, architecture, procedures, protocols, etc.
Data, analysis, or discussion if applicable.
List of documents, papers, links, GitHub issues, etc.
Supplementary figures, tables, or data.
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Krake is a network-connected alarm annunciator built around an ESP32 microcontroller, an LCD display, DFPlayer-based audio output, status LEDs, and a rotary encoder plus mute button for user interaction. It is intended as a flexible, open-source option for proprietary alarm panels and annunciators in clinical and research environments, particularly where alarms must be aggregated, prioritized, and presented across multiple beds or devices.
The device is designed to:
- Integrate with open communication protocols (e.g., Wi-Fi and MQTT) for alarm and status messages.
- Provide audible and visual alarms with configurable patterns and volumes.
- Serve as a testbed for alarm logic and human–machine interface experiments, especially in open, collaborative research.
This article focuses on the Rev 2.1 PCB manufactured by PCBWAY and the corresponding assembly, electrical testing and factory test procedure for a batch of twenty units (US0006–US00015, LB0006–LB00011, LDN0001–LDN0005).
Krake Rev 2.1 consists of:
- A custom ESP32-based PCB with power conversion, level shifting, and IO conditioning.
- A 20x4 character LCD for displaying alarm state and device information.
- An audio subsystem built around a DFPlayer-compatible MP3 module and an external speaker.
- User interface components, including a rotary encoder (with push-switch) and a dedicated mute button.
- Status and alarm LEDs to indicate power, connection state, and alarm categories.
If your bill of materials is long or complex, you can upload the details in an editable spreadsheet (e.g., ODS, Excel, or PDF file) to an open access online location, such as the Open Science Framework repository.
Start with receiving the subassembly KRK-PL-0002 (Krake Rev2.1 PCB, plus BOM-TBD, plus placement
| Qty | Reference(s) | Value | Datasheet | Cost | Description |
|---|---|---|---|---|---|
| 1 | KRK-PL-0001 | Subassembly, Krake Contract Manufacture | ~ | 1,000 | As built from parts list PCBWay |
| 1 | BZ601 | Speaker | ~ | 1 | 8 Ohm 2W Speaker, 28mm |
| 1 | J603 | DFPlayermini | DFPlayer Mini Manual | 3 | Mini MP3 Player |
| 1 | SD601 | Micro_SD_Card_16GB | -- | 7 | SanDisk 16GB SDHC SDSDB-016G |
| 1 | D105 | LED_RED | Lite-On RED LED | 0 | LED RED CLEAR T-1 3/4 |
| 5 | D201–D205 | LED_WHITE | Lite-On WHITE LED | 1 | LED WHITE CLEAR T-1 3/4 |
| 4 | MF403, MF406, MF409, MF412 | Nut_4-40_0.1875 | Keyelco Datasheet | $0.10 | #4-40 Hex Nut, 3/16" Steel |
| 1 | U302 | LCD_20x4_Character | -- | 5 | LCD 2004 20x4 Module |
| 4 | MF401, MF404, MF407, MF410 | Screw_4-40_0.375 | McMaster-Carr | 0 | 4-40 Phillips Pan Head, 3/8" |
| 4 | MF402, MF405, MF408, MF411 | Spacer_0.1875x0.125 | McMaster-Carr | 0 | Nylon Spacer, 1/8" Length |
| 6 | MF103, MF601–MF605 | LED_Standoff | -- | NA | General Alarm LED Standoffs |
| 1 | MF801 | ENCLOSURE_KRAKE_VER1 | McMaster-Carr | 1000000 | Plastic Enclosure |
| 1 | MF802 | PCB_KRAKE_VER1 | Gerbers2501181555.zip | 1000000 | PCB for Krake Rev 2.1 |
| 2 | MF701, MF702 | Jackscrews_4-40 | McMaster-Carr | 0 | Male–Female Cylinder Jackscrew |
| 1 each | ENC801–ENC806 | Enclosure Parts | -- | -- | Top/bottom/front/rear panels, knob, mute cap |
| 4 | MF807–MF810 | Screw_#6x1/2 | -- | -- | PanTorx Self-Tapping |
| 4 | MF803–MF806 | Screw_2-32x3/8 | -- | -- | Self-Tapping Phillips Pan Head |
| 1 | LB801 | Krake_Model_Serial | -- | -- | Serial Number Label |
Additional details may be found in the source design files. Material types and categories can be added in extended tables as needed.
This section documents the procedure used to complete assembly of Krake Rev 2.0 units from partially assembled boards from a contract manufacturer.
The following tools are required for through-hole assembly and rework:
- Sharpie or other indelible pen.
- Box cutter or similar.
- Soldering station with appropriate ventilation.
- 3/16 or 7/32 inch nut driver for the nuts on the LCD screws.
- #1 Phillips screwdriver.
- Diagonal or other flush-cutting hand tool for trimming leads.
- Basic ESD protection (wrist strap, mat) appropriate for handling microcontrollers and logic ICs.
- Assembly fixture or simple mechanical support to hold the PCB during soldering (optional but recommended).
For the GPAD, We made an assembly assistant / fixture by using a raw PCB with some long #6 screws and nuts to hold at the PCB mounting points. This same test fixture can be used for the Krake.
In addition four 4.40 screws with washers and 4-40 nuts to make a 1/8" spacer for holding the LCD and header for soldering.
An alternative is to make a 3D printed test bench
The file for which is here:
Platform_PWA-Part_PlatformPWABody_PlatformPWA20260114.zip
On the LCD module locate the J1 and J2 solder pads which if soldered ground the bezel.
Solder them.
As soldered.
NOTE, not all LCD modules have J1. This LCD module has only J2 pictured with solder on J2.
For each Krake assembly, load into a microSCHC Flash card several MP3 files. The files must be loaded in a specified order. The files are found at: https://drive.google.com/drive/u/1/folders/1j0NoWhTwpoMUFePJHcl5dvErf954-mCs There is a script file there, copy_to_sd.sh which on a Windows PC can copy the files in the required order to a microSCH Flash card. Run copy_to_sd.sh from the bash shell, by typing "./copy_to_sd.sh"
Screen shot of file explorer view of a programed card.
Note these files do not display in the order in which they were written.
This is a screenshot of successful copying of files.
The contract manufacturer order (approximately September 2025) provided partially assembled PCBs with all SMT components and some through-hole parts installed. These are referred to as sub-assemblies KRK-PL-0001.
Remove unit from shipping carton.
On the first unit, confirm that the PCB is marked as Rev 2.0 (or the revision for which this procedure is valid).
Create the unit’s serial number using the factory form at:
https://nk25719.github.io/krakeFactory/factory-form.html
Print the QR Model-Serial Number label, quantity TBD.
Each PCB has a designated silkscreen area for the serial number. The assembler should:
- Attach the model - serial number label at the provided location on the PCB.
- Record the serial number in the manufacturing log along with the date, assembler, and test status.
The Public Invention test and assembly records database is at:
https://nk25719.github.io/krakeFactory/records.html
Make a photograph of the unit, front and back with the model-serial QR code applied.
Before any additional soldering:
-
Visually inspect each PCB for:
- Obvious mechanical damage (cracks, severe warping).
- Bent, missing, or misaligned through-hole parts.
- Solder bridges on SMT components or incomplete joints.
- Test 976: Inspect for correct polarity on polarized parts (Electrolytic capacitors, Integrated Circuits, Diodes). See Figure 1 below image: Inspection1, component locator.
-
Confirm that the PCB is marked as Rev 2.1 (or the revision for which this procedure is valid).
Inspect for polarity
At this point install the MP3 Player sockets and the MP3 Player.
Solder at the MP3 Player, two 1×8 socket headers at J603.
The MP3 player audio module is installed using sockets to simplify rework and replacement.
- Install the DFPlayer header or socket into the designated footprint on the PCB.
- Solder the header pins from the bottom side of the PCB.
- On the LCD side of the PCB, trim the DFPlayer header leads so that they are flush or slightly below the surface and cannot contact the LCD module when installed.
Test the MP3 Player.
This section describes the validation of Krake units at the end of assembly. It includes electrical safety checks (unpowered and powered tests).
Before applying power, the following resistance measurements are taken between test points and ground (TP101). The goal is to detect shorts that could endanger the power supply or the DUT.
- Use a digital multimeter capable of measuring resistance into the megaohm range.
- Record the make, model, and serial number of the test instrument in the manufacturing log (for example, ASTRO DM6000AR, SSD card/N 2327610969 for units assembled in the USA).
- For each device under test (DUT), measure:
- TP100–TP101 (Controller V(_\mathrm{CC}) to GND).
- TP103–TP101 (+5 V to GND).
- TP102–TP101 (Vin to GND).
- TP302–TP101 (+12in).
- TP201–TP101 (VBus to GND).
- TP202–TP101 (V3 to GND).
Test point locator:
Test Points for Unpowered Tests
- None of the rails should be a hard short to ground.
- Vin (TP102) to GND should typically measure greater than 10 MΩ and appear capacitive.
- +5 V (TP103) to GND should also appear non-shorted and capacitive, often in the kiloohm range due to load network.
- V3 and Controller V(_\mathrm{CC}) should be non-shorted and may show a few hundred ohms due to on-board circuitry.
Example measurements for units showed:
| Test Point | Approximate Reading |
|---|---|
| TP100–TP101 | >10–15 MΩ |
| TP103–TP101 | 1.09–1.12 kΩ. |
| TP102 -TP101 | > 10MΩ |
| TP302–TP101 | OL |
| TP201–TP101 | 1.00–1.15 kΩ. |
| TP202–TP101 | 280–350 Ω |
If any unit shows significantly lower resistance than these ranges, the board should be inspected and reworked before power is applied.
Here is the end of the tests before any soldering is done.
Because the sockets for the Mini MP3 Player are covered by the LCD (once it is installed), we must therefore solder the sockets and test the Mini MP3 Player BEFORE we cover the solder connections with the LCD.
Steps:
- Solder in the Mini MP3 Player at J603
- Add speaker at J601 or J604
- Apply power at USB
- Make quick powered test. STOP IF OVER VOLTAGE on TP103 (5V) and TP100 (3.3V).
- Test Mini MP3 Player and Speaker procedure is below
- Navigate to krake\Firmware\factoryTest\FactoryTest_wMenu and open
FactoryTest_wMenu.ino - Using USB to USB C cable to connect the PCB to the computer
- Using device manager identify which port the PCB is connected to.
- When in Arduino IDE, navigate to Tools-Port- select port the PCB is connected to
- Proceed to select the board - esp32 dev board
- Upload to the board and allow missing libraries to be identified, library specifications are below and discussed in issue #274
- PubSubClient by Nick O'Leary
- Aruinojson by Benoit Blanchon
- LiquidCrystal I2C by Frank de Brabander
- ESPEssentials by Stephan Rumswinkel
- LittleFS_esp32 by lorol
- RotaryEncoder by Matthais Hertel
- DFRobotDFPlayerMini by DFRobot
- One upload is complete, navigate to the Serial Monitor within Arduino IDE
- Change the 'baud rate' to 115200
- Enter '4'- , '5'- , '6' - Speaker into the Serial Monitor
- After entering 6, the serial monitor will ask for confirmation of audio - enter Y/N to confirm or deny audio and pass or fail test
Video of upload procedure how to access serial monitor and completion of DF player tests https://github.com/user-attachments/assets/768d9384-23f0-49b5-ae81-178c29a44425
Finish Assembly: Solder the LCD and LEDs and continue powered testing.
After passing the unpowered tests, each unit is powered from a current-limited bench supply.
The following tests are to confirm that the 5V and 3.3V regulators provide the correct output voltage.
Additional tests verify that voltage is going through the decoupling resistors to the loads on the system (usually ICs).
- Connect the bench supply to J101 and set:
- Voltage: between 8 V and 12 V (test values around 8.3–8.4 V are typical).
- Current limit: less than 1 A, with 200–300 mA used as an initial safety limit.
- Power on the device, measure and record the current draw.
- On the serial monitor, run the LCD test to get characters on the LCD. Use test, "2 LCD (I2C)". With a small screw driver, adjust RV301 the CONTRAST poetntiometer for good character constrast. The current draw typicaly increases by about 0.02 Amps.
- Measure and record:
- TP109, 3v3Controller supply to U102.
- TP401, VccLCD supply for U301 and U302.
- TP405, Vcontrast for the LCD.
- TP100, 3.3 V at U103 regulator output
- Test point "5esp32" the input to the 3.3 V regulator (U103 input).
- TP103, +5 V from the +5V regulator U101
- TP306, +5Vraw for SPI interface
- TP501 Mini MP3 Player supply 5VDFP at C505+
- TP205, 3V3USB power to CH340 USB to UART chip.
- TP102, Vin into the +5V regulator U101.
- TP201, VBus power in on USB connector
- TP202, V3 on U501.
- J701 pin 2 (DB9), charge pump output negative.
Test points:
Test Points for Powered Tests
Locator for DB9 pins
Typical passing units in the first batch showed:
| Test Point | Approximate Reading |
|---|---|
| TP109 | ~ 3.3V |
| TP401 | ~ 5V |
| TP405 | ~ 2.5V |
| TP100 | ~ 3.3V |
| 5ESP32 | ~ 5V |
| TP103 | ~ 5V |
| TP306 | ~ 5V |
| TP501 | ~ 5V |
| TP205 | ~ 3.3V |
| TP102 | ~ 4.5V |
| TP201 | ~ 5V |
| TP202 | ~ 3.3V |
| J701 | ~ 6V |
Units that deviate significantly from these ranges require investigation (e.g., reflow of regulators, inspection of shorts or opens on the relevant nets). Spreadsheet to input results calculate averages , variation and deviance which can help identify if any results are anomalies. DC Powered Test - Spreadsheet Template.xlsx
- A quantity of four, nylon 1/8" spacers are placed at the four corners of the LCD sub module. One spacer may need to be trimmed to clear the roatary encoder.
- Place the LCD module onto its header footprint, ensuring correct orientation.
- Four 4-40 x 3/8" screws with 4-40 x 3/16" nuts go through both boards and are torqued to 3.4 - 4.8 Inch-Pounds. Hold the nut with an approprate wrench or nut driver.
- Solder the LCD header pins to the PCB while maintaining the LCD flat and level.
Soldering the LCD pins on the header.
The front panel LEDs provide visual alarm and status indication.
- Identify the LED footprints on the PCB and the corresponding LED colors (e.g., white vs. red).
- 5 white LED's (D201-D205)
- 1 red LED - Power ((D103) .
- For each LED:
- Note the flat edge on the plastic body indicating the cathode.
-
- Align the flat edge with the flat indicator on the PCB silkscreen.
- Insert the LED and ensure consistent height above the PCB - to do this 3D print and use 6 of the LED spacer files "U_Box_V105_GPAD_LED_Standoff_single.stl" within enclosure/parts_toPrint
- Solder the leads.
- Trim the leads carefully, taking care not to damage nearby transistors or other components.
- To avoid mixing LED colors:
- Install and solder all white LEDs first, then close and set aside their packaging.
- Open the red LED packaging only when needed; install, solder, and trim them as a separate step.
This section covers basic procedures for powering Krake and verifying that the assembled hardware operates safely under firmware control.
- Connect a current-limited DC bench supply to connector J101 (Vin).
- Set the supply to:
- Voltage: between 8 V and 12 V (typical test value: 8.3 V).
- Current limit: less than 1 A (typical safe upper bound: 200–300 mA for an unmuted system at idle).
- Ensure the DFPlayer module, LCD, and all LEDs are installed.
- Power on the bench supply and observe the current draw:
- If current immediately rises to the current limit, power off and investigate for shorts.
- Typical assembled boards draw on the order of 150–190 mA at 8.3–8.4 V during idle tests.
- Once current is within an expected range, observe:
- 5 V regulator output (~5.0 V).
- 3.3 V regulator output (~3.3 V).
- LCD backlight and any power/status LEDs.
- Navigate to krake\Firmware\factoryTest\FactoryTest_wMenu and open
FactoryTest_wMenu.ino - Using USB to USB C cable to connect the PCB to the computer
- Using device manager identify which port the PCB is connected to - this may involve disconnecting and reconnecting the PCB to see which ports appear.
- When in Arduino IDE, navigate to Tools-Port- select port the PCB is connected to
- Proceed to select the board - esp32 dev board
- Upload to the board and allow missing libraries to be identified, library specifications are below and within issue #274
- PubSubClient by Nick O'Leary
- Aruinojson by Benoit Blanchon
- LiquidCrystal I2C by Frank de Brabander
- ESPEssentials by Stephan Rumswinkel
- LittleFS_esp32 by lorol
- RotaryEncoder by Matthais Hertel
- DFRobotDFPlayerMini by DFRobot
- AsyncTCP by esp32Async
- ESPAsyncWebServer by esp32Async
- ElegantOTA by Ayush Sharma
- OneButton.h by Matthias Hertel
- One upload is complete, navigate to the Serial Monitor within Arduino IDE
- Change the 'baud rate' to 115200
- Enter 'P' into the Serial Monitor
- After entering P, the serial monitor will ask for provide instructions for each of the tests to determine a 'PASS' or 'FAIL', this will include answering 'Y' or 'N' and performing tasks (if it is required to carry out any test individually , simply enter the corresponding number from the menu below into the serial monitor)
The Tests are as below - please read prior to performing tests to ensure you have all relevant information at hand
-
[0] Power/ ID
- No input required / no prompt message
-
[1] Inputs (Encoder / Button)
- Rotate encoder CLOCKWISE
- Rotate encoder COUNTER-CLOCKWISE
- Press the encoder button within 10 seconds
-
[2] LCD (I2C)
- Adjust the potentiometer (above the Power LED , labelled "CONTRAST") to adjust the constrast of the LCD to display the text using a small flathead screwdriver
- Do you see 4 FULL lines, aligned, with no garbage characters?
- Press Y to PASS or N to FAIL (Enter optional).
-
[3] LEDs / Lamps
- LAMP1 blink
- Skipping LAMP2 drive (BUSY shared safety)
- LAMP3 (LAMP3) blink
- LAMP4 (LAMP4) blink
- LAMP5 (LAMP5) blink
- LED_Status (LED_Status) blink
- Did you see the LEDs/Lamps blink as expected?
- Press Y to PASS or N to FAIL (Enter optional).
-
[4] DF Player & [5] SD (DFPlayer card)
- No input required.
-
[6] Speaker
- Did you hear audio from the speaker?
- Press Y to PASS or N to FAIL (Enter optional).
-
[7] Wi-Fi AP
- No input required.
- Check SSID visible from phone / PC.
-
[8] Wi-Fi STA (manual SSID/PASS)
- Enter the name of your Wi-Fi.
- Enter the password for your Wi-Fi.
-
[A] LittleFS R/W
- no input required
-
[B] UART10 (USB Serial)
- Confirm prompt can be seen.
-
[C] SPI loopback
Verify SPI communication by connecting the Master Out Slave In (MOSI) pin directly to the Master In Slave Out (MISO) pin. Physical Loopback (Hardware): Connect a jumper wire directly between the MOSI and MISO pins on your connector.
- Connect MOSI <-> MISO on SPI header for automatic test: We will cut one of the rj12 connectors and then we short pins 6 and 2, check below image
- The final step is to connect the SPI connector and run the test using the [C] command in the command window.
- [D] RS-232 loopback
- Use a short wire to connect pins 2–3 on RS232.
- Use a short wire to connect pins 7–8 on RS232.
-
[E] ElegantOTA
- Once factory test is complete copy ip address given during factory test into browser, ElegantOTA server will start. Browse to http://IP/update:
If the wifi needs to be setup: then you will go through: step [8] Wi-Fi STA (manual SSID/PASS)
- After Wi-Fi STA connected successfully. ElegantOTA server will start. Browse to http://IP/update: Example: OTA endpoint: http://192.168.10.234/update
- Verify that you see the ElegantOTA upload page:
-
[F] Mute Button + LED
- Button: GPIO 35 | LED: GPIO 13 (LED_Status))
- Press the mute button twice. (q to quit)
- Short tap = ignored (accidental push).
- Hold too long = warning, try again.
After completing electrical and audio tests, each unit is loaded with the intended final firmware (e.g., GPAD_API) for field or system testing.
For each serial number:
-
Load the final firmware: - Upload .bin files "Krake_fw_vx.x.x.bin" & "Krake_littlefs_X.XX.bin" (X.XX references the version number of the files, please use the most recent version which can be found at /releases (Root Level).
-
Record:
- Firmware version string.
- MCU MAC address.
- Date of final test and tester initials.
-
Perform a brief smoke test of:
- Power-up behavior and LCD initialization.
- Encoder and mute button operation.
- At least one network interaction (e.g., connection to test Wi-Fi and MQTT broker if available).
Units that pass all steps above are considered ready for integration into larger Krake deployments or experimental setups.
- To begin the enclosure assembly navigate to "krake\enclosure\parts_toPrint", The following files within this folder are to be printed to assemble the enclosure. PLA or PETG at 0.2mm is recommended.
- "knob_Dshaft_15mmx6mmv1.3.stl"
- "U_Box_V105_Krake_RevB_TSHELL_V3.stl"
- "U_Box_V105_Krake_RevB_FPanL_V3.3mf.stl"
- "U_Box_V105_Krake_RevB_BSHELL_V3.stl"
- "U_Box_V105_Krake_RevB_BPanL_V3.3mf.stl"
- "U_Box_V104_General_Alarm_Device_button"
- "Recess_bottom.stl"
- "SD_door.stl"
- Once all parts have been printed, the following tools and parts are required to add the threaded insert into the VESA and Speaker Mount.
- insert information about tools etc for threaded inserts
- To assemble the enclosure the following is required:
- "knob_Dshaft_15mmx6mmv1.3.stl"
- "U_Box_V105_Krake_RevB_TSHELL_V3.stl"
- "U_Box_V105_Krake_RevB_FPanL_V3.3mf.stl"
- "U_Box_V105_Krake_RevB_BSHELL_V3.stl"
- "U_Box_V105_Krake_RevB_BPanL_V3.3mf.stl"
- "U_Box_V104_General_Alarm_Device_button"
- "Recess_bottom.stl"
- "SD_door.stl
- Diagram to show how parts correlate to eachother and what bolts, and screws are required
Ethics statements
To be completed if human or animal data are involved (likely not applicable for this purely hardware manufacturing article).
CRediT author statement
To be completed (e.g., Conceptualization, Methodology, Software, Validation, Writing, Supervision, etc.).
Acknowledgements
To be completed with collaborators, institutions, and funding information.
References
To be completed with references to related open hardware, alarm standards, and the Krake/GPAD repositories or previous publications.