Project · draft
Haptic Distance Wristband (ToF Sensor, Vibration Feedback)
- intermediate
- 8-10 hours
A low-cost, repairable feedback aid prototype, co-designed with people with low vision, supports inclusion of persons with disabilities (target 10.2).
Safety notes
- LiPo: use a cell with a protection circuit, check polarity before connecting to the XIAO BAT pads, never puncture, crush or short it, and stop using a swollen cell.
- Prototype only: it does not replace a white cane or orientation and mobility training. ToF sensors can miss glass, very dark surfaces and objects outside the narrow beam (e.g. drop-offs).
Draft and unofficial, not affiliated with Fab Academy or the United Nations. Check prices, GST and parts before you buy.
Summary
A wrist-worn unit that vibrates faster as an object gets closer (up to about 3-4 m indoors). Built on a small milled board with a LiPo, and designed with users rather than for them.
What it teaches
Read a VL53L1X time-of-flight sensor over I2C, map distance to vibration intensity and rhythm with PWM through a MOSFET and flyback diode, design a wearable enclosure, and run user tests to tune the feedback.
Topics it touches, in Fab Academy-style terms:
- Electronics design
- Electronics production
- Input devices
- Output devices
- 3D scanning and printing
- Embedded programming
Parts list
Parts cost
Some parts are not priced yet, so there's no total.
7 required parts are marked not priced yet below. Where a price is known it is shown per part, GST-inclusive as the seller listed it on 24 Oct 2026, with the GST rate unverified. Shipping is not included.
| Part | Qty | Unit | Price, GST-incl. as listed | Line cost | GST | Source |
|---|---|---|---|---|---|---|
| Seeed Studio XIAO ESP32C3 Wi-Fi & BLE Development Boardxiao-esp32c3 | 1 | pcs | ₹734 | ₹734 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| VL53L1X time-of-flight distance sensorvl53l1x-tof | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| Coin vibration motor (ERM), 3 Vvibration-motor-coin | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| N-channel MOSFET, SOT-23mosfet-nch-sot23 | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| 1N5819 Schottky diode (flyback)diode-schottky-1n5819Flyback across motor | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| 10 kOhm resistor, 1206 SMDres-10k-1206Gate pull-down | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| 100 ohm resistor, 1206 SMDres-100ohm-1206Gate resistor | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| LiPo cell 3.7 V ~500 mAh with protection circuit and JST leadlipo-3.7v-500mah-jst | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| 15cm x 10cm Single Side Copper Clad Laminate PCB Boardpcb-copper-clad-15x10 | 1 | sheet | ₹39 | ₹39 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| Part | Qty | Unit | Price, GST-incl. as listed | Line cost | GST | Source |
|---|---|---|---|---|---|---|
| Type C USB Cable (1 metre)cable-usb-c-1mSkip if you already have a data-capable USB-C cable | 1 | pcs | ₹65 | ₹65 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| Premium 1.75MM HS PLA 1 KG 3d Printer Filament - Cement grey Colourfilament-pla-1kgCase; Fab Lab stock | 1 | pcs | ₹741 | ₹741 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| Optional extras total, GST-inclusive as listed by the seller | ₹806 | |||||
The Part column links to the shared catalogue. Units are pcs, m, g, sheet or set, and a "set" is the seller's pack, as noted per part.
Tools you will need
- PCB mill
- Soldering iron
- 3D printer
- Fabric or hook-and-loop strap (unpriced)
Build notes
Step-by-step build notes have not been written yet for this draft. The summary, the topics above and the parts list are what exists so far.
How to buy
There is no online checkout. To buy or import these parts, email info@curiosta.com and say what you need. The button opens your own email app with a draft; nothing is sent until you send it.
Prices on this site are third-party seller listings, not a Curiosta quote. Ask by email for availability, price and GST.