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Table of Contents
NFC-enabled Tool Lockers
See also https://roundup.ehlab.uk/issues/issue76
We have portable tools that require training before use, or which are valuable and at risk of being borrowed or stolen. The proposed solution is to create individual lockable compartments operated by our existing NFC tokens.
Compartments
We will purchase a KALLAX shelf from IKEA. This will provide 8 spaces of 33x33x38cm. The back of the cabinet will be closed with a sheet of wood.
Doors will be laser-cut from 5-6mm clear acrylic. They will be mounted to the KALLAX with cabinet hinges designed for glass doors (a few varieties are available).
The unit will be placed in the workshop, under the workbench where the small bench grinder/sander is mounted.
Mechanical
Electric cabinet locks [DSCK7267] will be used to secure the doors. These locks are 12V operated, fail-secure, and with a closure detection switch. A TTP223 touch sensor module will be used to trigger the release of an individual lock after authentication via NFC.
Electronics
A single controller will operate a group of 8 lockers. The electronics will be based on the tool/door controllers, using an ESP8266 microcontroller and PN532 NFC module. I2C expanders will be used:
- to interface to an 8-way relay board to control the locks
- to interface to the touch sensors
- to interface to the lock closure sensors
Addressable RGB LED strip will be installed in each compartment to provide status feedback (tool checked in/out, compartments authorized after an NFC swipe).
User Interface
There will be one NFC reader for the group of 8 lockers.
- Present token to the reader
- Lockers that are authorized for the user will light up while others remain dark
- User touches the handle (touch plate) of the locker they wish to open
- Selected locker pops open. Other lockers deactivate (present token again to open another locker).
Use Cases
Some of the tools or equipment that might be stored securely (some of these are only likely to be purchased if secure storage is available):
- Makita cordless tools (to avoid borrowing or theft)
- Angle grinders (to ensure that users are trained)
- Good quality measurement tools (calipers, micrometers)
- Hand tool kits with easily lost parts
Tasks
- Cabinet installation
Buy KALLAX cabinet (Tim will do this)Build KALLAX cabinetInstall a sheet of wood to close-off the backRemove existing support leg from workbenchInstall cabinet under bench- Brace the workbench (transfer the load of the workbench onto the KALLAX)
- Doors
- Buy material from Hobarts (4x 800x450x6mm clear acrylic)
- Design the door for laser cutting:
- 330x330mm
- Rounded corners (say 5mm radius?)
- Holes for selected hinges
- Holes for mounting lock and touch sensor plate
- Test cut in MDF
- Fit to cabinet
- Lock assembly
- Create a jig to mount the lock in the correct (repeatable) position relative to the catch on the door
- Decide how to screw the lock into the KALLAX
- Install wiring
- for lock release, lock sensor, touch sensor and LED strip
- use alarm cable and leave a tail at the back of the cabinet for connection to the electronics
- Electronics
- Based on tool access controller
- Blue box with clear lid
- 20×4 LCD
- NFC module
- Tool controller PCB
- Cable to back of KALLAX (ground, 5V, SDA, SCL, LED bus)
- Additional electronics behind the KALLAX (or at the back of one unit with a cover)
- 12V PSU for relays
- 5V PSU for electronics and LEDs
- 8-way relay module
- I2C expander for relays
- I2C expander for touch sensors
- I2C expander for lock closure switches
- Screw terminals to terminate power/relays/touch/closure/LED-in/LED-out for each locker
- It will make wiring/testing easier to have a clear termination point for each locker's cable
- Software
- Will be based on the door/tool controller software
- (plenty of changes required)
- Tim is stuck with this task
Parts
KALLAX | |
Clear acrylic sheets 4 of 800x450x6mm | |
Cabinet hinges | 4 pairs in stock for testing, 4 more needed for complete set |
Touch plates | |
Pop-rivets (for touch plates/lock) | in stock |
Locks (DSCK7267) | in stock |
Touch sensors (TTP223) | in stock |
8-way 12V relay module | in stock |
I2C expanders (PCF8574) | in stock |
Wemos D1 Mini ESP8266 | in stock |
12V 3A power supply | |
12V→5V DC-DC converter | |
WS2812 LED strip |