Project · draft
Solar Food Dryer with Fan and Temperature Control
- intermediate
- 10-12 hours
Drying surplus fruit, vegetables and herbs with sunlight cuts post-harvest loss and keeps food longer without grid power.
Safety notes
- Food safety: use food-grade stainless mesh only (no galvanised or painted mesh), keep insects out with fine screens, and follow tested drying guidance for each food.
- Heat: collector surfaces get hot in full sun; acrylic glazing softens if overheated, so vent the box.
- 18650 cells: use protected cells, set any boost/buck output with a multimeter before connecting the board, never short the cell, and do not leave charging unattended.
Draft and unofficial, not affiliated with Fab Academy or the United Nations. Check prices, GST and parts before you buy.
Summary
A tilted collector heats air that rises through food-grade mesh trays. An RP2040 reads tray temperature and humidity and runs a fan to vent moisture and cap temperature, logging a drying curve so you can tell when a batch is done.
What it teaches
Design a laser-cut plywood box dryer with a clear glazing and airflow path, measure air temperature and humidity at the trays, and run a solar-charged fan through a MOSFET with hysteresis to keep drying air within a safe band.
Topics it touches, in Fab Academy-style terms:
- Computer-controlled cutting
- Input devices
- Output devices
- Electronics production
- Embedded programming
Parts list
Parts cost
Some parts are not priced yet, so there's no total.
14 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 |
| DHT22 Humidity and Temperature Sensor Module (AM2302)dht22-moduleAt the tray | 1 | pcs | ₹115 | ₹115 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| DS18B20 waterproof temperature probe (1-Wire), ~1 m leadds18b20-waterproofCollector outlet | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| 4.7 kOhm resistor, through-hole (pack of 10)resistor-4k7-x101-Wire pull-up; uses 1 | 1 | set | not priced yet | not priced yet | GST unverified | no seller yet |
| DC fan, 5 V, 40 mmfan-5v-40mm | 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 fan | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| 10 kOhm resistor, 1206 SMDres-10k-1206 | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| 100 ohm resistor, 1206 SMDres-100ohm-1206 | 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 |
| 18650 2200mAh 3.7v Cylinder Rechargeable Li-Ion Battery (Any Colour)battery-18650-2200mahProtected cell | 1 | pcs | ₹137 | ₹137 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| Single 18650 battery holder with leadsholder-18650-1cell | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| TP4056 Li-ion charger module with DW01 protection (USB-C)tp4056-protected-module | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| Small solar panel, ~6 V 1-2 Wsolar-panel-6v-1w | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| MT3608 DC-DC boost converter moduleboost-mt36085 V for XIAO and fan; set before connecting | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| Plywood sheet, 6 mm (laser/CNC)plywood-6mm-sheet | 2 | sheet | not priced yet | not priced yet | GST unverified | no seller yet |
| Cast/extruded acrylic sheet, 3 mm (laser-cut parts)acrylic-3mm-sheetGlazing | 1 | sheet | not priced yet | not priced yet | GST unverified | no seller yet |
| Food-grade stainless steel mesh (fine)mesh-stainless-food-gradeTrays | 2 | sheet | not priced yet | not priced yet | GST unverified | no seller yet |
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 (6 mm plywood) or CNC router
- Soldering iron
- Multimeter
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.