# Arduino MKR

### Overview

The **Arduino MKR Data Logger** is a microcontroller-based platform that can be used to operate a 3D-PAWS weather station. It provides low-power sensor polling, local data storage, and optional cellular data transmission.

The MKR platform runs the **3D-PAWS MKR Full Station firmware**, which reads environmental sensors, timestamps observations, and stores measurements locally on a microSD card. When connectivity is available, data can be transmitted to remote services such as **CHORDS** for visualization and analysis.

The MKR system is designed for **compact, low-power weather stations**, making it suitable for solar-powered deployments and experimental monitoring systems.

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### Supported Hardware

The MKR implementation typically uses one of the following boards:

* **Arduino MKR NB 1500** – LTE cellular connectivity
* **Arduino MKR GSM 1400** – GSM cellular connectivity

Supporting components typically include:

* MicroSD card for local data storage
* Real-Time Clock (RTC) module
* Cellular SIM card
* Cellular antenna
* EEPROM memory

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### Instruction Slides for Assembling the Data Logger

{% embed url="<https://docs.google.com/presentation/d/1hOtuYt_uVrD-8RlnOs4yGO56pUlioobT/view>" %}

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### Sensors Supported

* Light sensor
* Rain Gauge
* Anemometer
* Wind Vane
* Radiation Shield (Temperature, Pressure, & Relative Humidity)
* Globe Temperature
* Air Quality (PM 1.0, 2.5, 10)
* Distance Gauge (Stream, Storm Surge, and Snow Height)
* Soil Moisture and Temperature
* Leaf Wetness

Additional sensors may be integrated depending on the station configuration.

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### Data Flow

In a typical MKR-based station, data flows through the system as follows:

```
Sensors
   ↓
Arduino MKR Data Logger
   ↓
Local Storage (microSD card)
   ↓
Cellular Network
   ↓
CHORDS Data Portal
   ↓
Grafana Visualization
```

Local storage ensures measurements are preserved even if connectivity is temporarily unavailable.

***

### Firmware

The firmware used for MKR-based stations is available from the 3D-PAWS GitHub repository:

**3D-PAWS MKR Full Station**

{% embed url="<https://github.com/3d-paws/3D-PAWS-MKR-FullStation>" %}

The repository contains:

* station firmware
* configuration parameters
* sensor interface libraries
* hardware pin mappings

Users should download the latest version when configuring a station.

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### Notes

* Stations using MKR should be fully tested before deployment to verify sensor readings and connectivity.
* A properly configured **SIM card and cellular signal** are required for remote data transmission.
* Local SD storage provides a backup if cellular connectivity is interrupted.

***

### MKR Wiring Diagram

<figure><img src="https://3872952369-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FOPo6sjPamohjSzU18zL8%2Fuploads%2FXuSfBby3kBK2PwoNJPFU%2FMKR1500-v260324.png?alt=media&#x26;token=c073fd96-5057-4827-9121-a1f81669cf5e" alt=""><figcaption></figcaption></figure>