Bill of Materials
π Smart Swimming Pool: Complete shopping list with part numbers, prices, and sourcing tips.
This BOM covers all components needed to build the pool controller including the electronics, electrical installation, sensors, and enclosure. Prices are estimates as of 2026.
1. Controller Electronics
These parts make up the core pool controller. All items are standard maker/hobbyist components.
| # | Component | Qty | Est. Price | Details | Example Source |
|---|---|---|---|---|---|
| 1 | ESP32 DevKit V1 (CP2102) | 1 | 10β15 β¬ | 4MB flash, CP2102 USB-serial | Amazon, AZ-Delivery |
| 2 | 2-Channel 5V Relay Module | 1 | 5β8 β¬ | Active-low, optocoupler isolated, HW-279/HW-316 | Amazon, eBay |
| 3 | DS18B20 temperature sensor (waterproof) | 2 | 4β6 β¬/ea | Stainless steel probe, 1m cable, 3-wire | Amazon, Reichelt |
| 4 | 4.7kΞ© resistor (ΒΌW, Β±5%) | 2 | 0.10 β¬/ea | Metal film or carbon film | Reichelt, Pollin |
| 5 | Breadboard (830 tie points) | 1 | 3β5 β¬ | For prototyping | Amazon, Reichelt |
| 6 | Jumper wires (M-M, M-F) | 20+ | 3β5 β¬ | Assorted colors/lengths | Amazon |
| 7 | USB power supply (5V, 1A+) | 1 | 5β10 β¬ | Quality brand (Anker, Samsung, Apple) | Local electronics store |
| 8 | USB-A to Micro-USB cable | 1 | 3β5 β¬ | Data cable (not charge-only) | Amazon |
| | Subtotal (controller only) | | ~35β55 β¬ | | | | (Existing BOM = 45β75 β¬ incl. enclosure) | | | |
2. Enclosure & Mechanics
Protect the electronics from moisture and physical damage.
| # | Component | Qty | Est. Price | Details | Example Source |
|---|---|---|---|---|---|
| 9 | DIN rail enclosure (ABS, IP54+) | 1 | 8β15 β¬ | e.g. Fibox 4-module, 100Γ75Γ105mm | Reichelt, Conrad |
| 10 | DIN rail (35mm, 15cm) | 1 | 2β4 β¬ | Slotted steel rail for mounting | Reichelt |
| 11 | PG7 cable gland (5β7mm cable) | 4β6 | 1β2 β¬/ea | For sensor cables and USB entry | Amazon, Reichelt |
| 12 | PG11 cable gland (8β10mm cable) | 1β2 | 1β2 β¬/ea | For mains cable entry (if 230V in enclosure) | Amazon, Reichelt |
| 13 | DIN rail mount adapter for ESP32 | 1 | 3β5 β¬ | 3D-printed optional; zip ties also work | Thingiverse |
| 14 | Zip ties (100mm, assortment) | 10+ | 2β3 β¬ | Cable management inside enclosure | Any hardware store |
| 15 | Adhesive cable tie mounts | 5+ | 3β4 β¬ | Stick to enclosure interior | Amazon |
| | Subtotal (enclosure) | | ~25β45 β¬ | | | | Not required if breadboard is used indoors | | | |
3. Electrical Installation (230V)
For connecting the relay module to the pumps safely.
| # | Component | Qty | Est. Price | Details | Notes |
|---|---|---|---|---|---|
| 16 | RCD / FI circuit breaker (30mA) | 1 | 20β35 β¬ | 2-pole, 25A, 30mA rated residual current | Mandatory for 230V |
| 17 | MCB / circuit breaker (B10A or B16A) | 1β2 | 5β10 β¬/ea | For pump circuit overcurrent protection | Per pump circuit |
| 18 | Three-core mains cable (NYM-J 3Γ1.5mmΒ²) | 5β10m | 2β3 β¬/m | For 230V wiring between relay and pumps | Hardware store |
| 19 | Flexible control cable (LiYY 3Γ0.75mmΒ²) | 2β3m | 1β2 β¬/m | For relay β pump connection inside enclosure | Reichelt |
| 20 | Wire ferrules (0.75mmΒ² and 1.5mmΒ²) | 20+ | 3β5 β¬ | For stranded wire termination in screw terminals | Reichelt, Amazon |
| 21 | Ferrule crimping tool | 1 | 8β15 β¬ | For crimping ferrules | Reichelt, Amazon |
| 22 | DIN rail terminal blocks (2.5mmΒ², grey) | 4β6 | 1β2 β¬/ea | For wiring distribution inside enclosure | Reichelt, Wago |
| 23 | DIN rail grounding terminal (green-yellow) | 2 | 2β3 β¬/ea | For PE / ground connection | Reichelt |
| 24 | End brackets for terminal blocks | 2 | 1 β¬/ea | Fix terminal blocks on DIN rail | Reichelt |
| 25 | Cable markers (numbered rings) | 1 set | 3β5 β¬ | For identifying wires during maintenance | Reichelt |
| 26 | Strain relief for mains cable | 2 | 2β4 β¬/ea | Prevent cable pull from reaching terminals | Hardware store |
| | Subtotal (electrical) | | ~60β110 β¬ | | | | Many items may already be in your distribution panel | | | |
4. Temperature Sensor Installation
Additional materials for mounting DS18B20 sensors on pipes.
| # | Component | Qty | Est. Price | Details | Notes |
|---|---|---|---|---|---|
| 27 | DS18B20 stainless steel probe (9mm Γ 30mm) | 2 | 4β6 β¬/ea | Better quality than generic β look for “Sanitary” variant | Reichelt, Amazon |
| 28 | Sensor cable (4-conductor, shielded, 2Γ0.25mmΒ²) | 5β15m | 2β3 β¬/m | For extending sensor reach; twisted-pair shielded preferred | Reichelt |
| 29 | Heat shrink tubing (assorted, 3:1 ratio) | 1 set | 3β5 β¬ | For sealing cable connections against moisture | Amazon |
| 30 | Cable clips (for pipe mounting) | 10+ | 2β3 β¬ | Fix sensor cable along pipe runs | Hardware store |
| 31 | Thermal conductive paste (heat sink compound) | 1 tube | 3β5 β¬ | Improves thermal contact between probe and pipe | Reichelt |
| 32 | Cable junction box (IP44+) | 1 | 3β5 β¬ | For connecting sensor extension cables | Hardware store |
| | Subtotal (sensor installation) | | ~25β45 β¬ | | | | Depends strongly on cable lengths needed | | | |
5. Tools & Consumables
Essential tools for assembly β not included in the controller cost.
| # | Tool | Est. Price | Required? | Notes |
|---|---|---|---|---|
| 33 | Digital multimeter | 15β30 β¬ | β Yes | Must measure DC voltage, continuity, resistance |
| 34 | Wire stripper (automatic) | 8β15 β¬ | β Yes | For stripping 0.75β2.5mmΒ² wires |
| 35 | Screwdriver set (slotted + Phillips) | 5β10 β¬ | β Yes | For terminal blocks and DIN rail components |
| 36 | Soldering iron (30W+) | 15β25 β¬ | β¬ Optional | Only if you solder sensor extensions |
| 37 | Heat gun | 15β30 β¬ | β¬ Optional | For heat shrink tubing |
| 38 | Cable tester (continuity tester) | 5β10 β¬ | β¬ Optional | For verifying wired connections |
| | Subtotal (tools) | | ~60β100 β¬ | | | | May be partially available in your workshop | | | |
Order of Purchase
If you are ordering everything at once, here is the priority:
- Must-have (ESP32, relay, sensors, resistors, breadboard, PSU) β ~35 β¬ β Enough to flash firmware and test sensors
- Enclosure + glands + DIN rail β ~25 β¬ β For permanent installation
- Electrical (RCD, MCB, cable, terminals) β ~60 β¬ β Only if you need to extend your distribution panel
- Sensor installation (cable, heat shrink) β ~25 β¬ β Only if running sensors to distant pipe locations
You can start with just the must-have items (category 1) and expand later.
Sourcing Tips
| Item | Tip |
|---|---|
| ESP32 | Buy from AZ-Delivery (Germany) β known quality, fast shipping. Avoid “ESP32 WROOM” from no-name sellers. |
| DS18B20 | Search for “DS18B20 sanitary sensor” β these have better sealing. Cheap ones (<2β¬) often fail after 1β2 seasons. |
| Relay module | Ensure it says optocoupler isolated and active-low. HW-279 is the most reliable model. |
| RCD / FI | Buy from Hager, ABB, Schneider, or Siemens. Avoid no-name safety switches. |
| Cable | NYM-J is standard for fixed installation. LiYY is for flexible internal wiring. |
| Resistors | 4.7kΞ©, ΒΌW, Β±5% β literally 10 cents. Buy 10, keep spares. |
Price Summary
| Category | Main Components | Price Range |
|---|---|---|
| Controller Electronics | ESP32, relay, sensors, breadboard, PSU | 35β55 β¬ |
| Enclosure & Mechanics | Enclosure, glands, DIN rail, fittings | 25β45 β¬ |
| Electrical (230V) | RCD, MCB, cable, terminals, ferrules | 60β110 β¬ |
| Sensor Installation | Extra cable, heat shrink, junction box | 25β45 β¬ |
| Tools | Multimeter, stripper, screwdrivers | 60β100 β¬ |
| Total (controller only) | Categories 1β2 | 60β100 β¬ |
| Total (full installation) | Categories 1β4 | 145β255 β¬ |
| Including tools | Categories 1β5 | 205β355 β¬ |
π‘ The existing “Getting Started” BOM estimates 45β75 β¬ for the controller electronics + enclosure (categories 1+2). The expanded BOM above adds the electrical installation (230V) and sensor mounting materials which are necessary for a real pool installation.