Project · draft
Rainwater Tank Level Monitor over LoRa (865 MHz)
- intermediate
- 10-14 hours
SDG 6 · Clean Water and Sanitation
Knowing how much harvested rainwater is in a rooftop or community tank helps households and schools plan use and avoid overflow.
Safety notes
- Work on roofs and tank lids only with someone present and a secure footing; never lean into tanks.
- India: use the licence-exempt 865-867 MHz band (WPC de-licensed it for low-power devices within the power limits in its notification); keep the module's default low power, use the IN865 settings, and buy modules whose seller states WPC ETA compliance. Never use 433 or 915 MHz modules.
- 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.
- Keep electronics outside the tank and drinking water uncontaminated: only the sealed sensor faces the water, nothing enters it.
Draft and unofficial, not affiliated with Fab Academy or the United Nations. Check prices, GST and parts before you buy.
Summary
A node on the tank lid reads the water surface distance every 15 minutes and sends the level to a second XIAO indoors with an OLED showing litres and a 7-day trend. No Wi-Fi needed at the roof.
What it teaches
Measure water level with a sealed ultrasonic sensor from the tank lid, convert distance to litres from tank geometry, send compact LoRa packets to an indoor receiver, and run on a solar-charged cell with deep sleep.
Topics it touches, in Fab Academy-style terms:
- Input devices
- Networking and communications
- Embedded programming
- 3D scanning and printing
- System integration
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-esp32c3Tank node and indoor receiver | 2 | pcs | ₹734 | ₹1,468 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| LoRa transceiver module, 865–867 MHz (India IN865 band)lora-865mhz-inIN865 settings | 2 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| JSN-SR04T waterproof ultrasonic distance sensorjsn-sr04t-waterproof | 1 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| 1k Ohm Resistor - (Pack of 10)resistor-1k-x10Echo divider if your sensor outputs 5 VPack: pack of 10 | 1 | set | ₹12 | ₹12 | 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 |
| PG7 nylon cable glandcable-gland-pg7 | 2 | pcs | not priced yet | not priced yet | GST unverified | no seller yet |
| 0.96 Inch OLED Display Module SPI/I2C 4pin Blue Coloroled-096-i2cReceiver display | 1 | pcs | ₹167 | ₹167 | GST unverified, typically 18% | Robocrazeread 24 Oct 2026 |
| PETG 3D printer filament, 1.75 mm, 1 kgfilament-petg-1kgOutdoor housing | 1 | pcs | 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
- 3D printer (PETG)
- 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.