Project · draft
Weigh-and-Price Helper Scale for Home Micro-Businesses
- intermediate
- 6-8 hours
A repairable, low-cost scale helps home food and craft sellers portion, cost and price goods consistently, protecting thin margins.
Safety notes
Read first. Not legal-for-trade. In India, scales used to sell goods must be verified and stamped under the Legal Metrology Act. Use this one for portioning, recipes and costing only.
- Not legal-for-trade: in India, weighing instruments used to sell goods must be verified and stamped under the Legal Metrology Act. Use this for portioning, recipes and costing only.
- Do not overload the cell past its rating; add a mechanical stop under the platform.
Draft and unofficial, not affiliated with Fab Academy or the United Nations. Check prices, GST and parts before you buy.
Summary
A kitchen-sized scale with a laser-cut body: weigh an ingredient or finished pack, enter a price per kg with buttons, and read the price and batch cost on screen. Aimed at home bakers, pickle makers and craft sellers who need consistent portions and costing.
What it teaches
Read a strain-gauge load cell through an HX711 24-bit ADC, calibrate with known weights, filter noisy readings, and build a tare / unit-price / batch-cost interface on an OLED. Design a laser-cut cantilever mount that keeps the load cell in bending only.
Topics it touches, in Fab Academy-style terms:
- Input devices
- Computer-controlled cutting
- Embedded programming
- Mechanical design
Parts list
Parts cost
Some parts are not priced yet, so there's no total.
3 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 RP2040 Development Boardxiao-rp2040 | 1 | pcs | ₹513 | ₹513 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| Bar-type strain-gauge load cell, 5 kgload-cell-5kg-barNeeds M4/M5 mounting screws, often supplied with the cell | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| HX711 24-bit load-cell amplifier modulehx711-module | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| 0.96 Inch OLED Display Module SPI/I2C 4pin Blue Coloroled-096-i2cI2C 0x3C | 1 | pcs | ₹167 | ₹167 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| 4-Pins DIP Momentary Square Tactile Push Button Switch 10 Pieces - 6x6x5mmbutton-tactile-6x6-x10Uses 4: tare, unit, price up/downPack: pack of 10 | 1 | set | ₹16 | ₹16 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| 40x1 Pin 2.54mm Pitch Male Berg Stripheader-male-40x1 | 1 | pcs | ₹8 | ₹8 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| Male to Female Jumper Wires (20cm) (20pcs)jumpers-f2m-20cm-20Pack: pack of 20 male-female 20cm | 1 | set | ₹28 | ₹28 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| MDF or plywood sheet, 3 mm (laser-cut parts)mdf-3mm-sheetLaser-cut body, platform and overload stop; Fab Lab stock | 1 | sheet | not priced yet | not priced yet | GST unverified | no seller yet |
| 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 |
| Optional extras total, GST-inclusive as listed by the seller | ₹65 | |||||
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
- Laser cutter (3 mm MDF)
- Soldering iron
- Known reference weights for calibration (e.g. sealed 500 g / 1 kg packs)
- Laptop with Arduino IDE or MicroPython
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.