A repository of Arduino-based sensor monitoring scripts tailored for DIY applications.
I created this project because I wanted a water flow sensor to help determine when and how much water is being used on this (100GPD) RO filter I got from amazon. It also assists with knowing around when to replace the filters for the system. Both wired and wireless should work but let me explain:
- The "UNOwatermonitoing" folder contains code for the (wired) ArduinoUNO, using this hall effect sensor
- The "WiFiAdvancedWaterFlowMonitor" folder contains code for the (wireless) [Arduino UNO R4 Wifi]
Key features of the project: Both scripts display water useage measurement in gallons, pretty accurately too! 😎 The wireless version of the code has a simple dashboard displaying water usage (see the example). The wired version has a python script that prints output from the console but, this script still needs work in order to achieve similar functionality to the wireless version.
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Live Demo: Water Usage Monitor App - Track water flow using a YF-S201 sensor and serve live data through a simple web interface.
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Credits:
Here’s the complete README in raw Markdown you can copy-paste directly:
# DWC Water-Temp Guardian for Arduino R4 WiFi
A self-contained temperature-control, monitoring, and alerting solution for Deep-Water Culture (DWC) hydroponic reservoirs.
* **Hardware**: Arduino UNO R4 WiFi, DS18B20 probe, TEC1-12706 Peltier module, IRLZ44N MOSFET (low-side), 12 V / 6 A PSU, on-board 12 × 8 LED matrix
* **Features**
* Samples water temperature every **10 s**
* Maintains water between **17 °C – 20 °C** (MOSFET on D8)
* Streams JSON metrics to **Telegraf** (HTTP listener on port 8125)
* Sends **IFTTT** alerts if temp stays out-of-band ≥ 60 s (15-min cooldown)
* Scrolls live temperature on the LED matrix every 5 s
---
## 1 Bill of Materials
| Qty | Part | Notes |
| --- | ---- | ----- |
| 1 | Arduino UNO R4 WiFi | ESP32-S3 coprocessor, LED matrix |
| 1 | DS18B20 waterproof sensor | + 4.7 kΩ pull-up |
| 1 | TEC1-12706 Peltier + heatsink/fan | good hot-side cooling **required** |
| 1 | IRLZ44N logic-level MOSFET | TO-220 package |
| 1 | 12 V ≥ 6 A DC supply | dedicated for Peltier |
| — | Wiring, 150 Ω gate resistor, 10 kΩ pulldown, Schottky diode | misc |
> ⚠️ The Arduino **only** drives the MOSFET gate. The TEC’s current flows directly from the 12 V supply.
---
## 2 Wiring
12 V(+) ───────► TEC + TEC – ───► MOSFET D MOSFET S ──────► GND ◄── Arduino GND Arduino D8 ─150 Ω─► MOSFET G │ └─10 kΩ─► GND
Common ground is mandatory.
Add a Schottky diode (e.g., 1N5819) across the TEC for surge protection.
---
## 3 Software Setup
### 3.1 Secrets
Create **`arduino_secrets.h`**:
```cpp
#define SECRET_SSID "your-ssid"
#define SECRET_PASS "your-wifi-password"
#define SECRET_IFTTT_KEY "xxxxxxxxxxxxxxxxxxxxxx"
Install via Library Manager:
- WiFiS3
- OneWire
- DallasTemperature
- ArduinoHttpClient
- Open
dwc_water_temp_guardian_hysteresis.inoin the Arduino IDE - Select Arduino UNO R4 WiFi board
- Verify → Upload
[[inputs.http_listener_v2]]
service_address = ":8125"
data_format = "json_v2"Grafana gauge query (last 30 s):
from(bucket: "dwc_temp_monitoring")
|> range(start: -30s)
|> filter(fn: (r) =>
r._measurement == "http_listener_v2" and
r._field == "temperature")
| Condition | Action | State |
|---|---|---|
| Temp > 20 °C | MOSFET HIGH | Cooling ON |
| Temp < 17 °C | MOSFET LOW | Cooling OFF |
LED matrix scrolls the latest reading; serial console logs raw values.
- No Wi-Fi → verify
SECRET_SSID/PASS, 2.4 GHz only - No metrics → check Telegraf listener
http://<host>:8125/dwc-temp-monitor - Peltier always ON/OFF → ensure hot-side heatsink fan is powered and DS18B20 probe is submerged
MIT © 2025 Mo