Understanding Master Uploads

When using Nightscout Pro, it’s important to understand the concept of “Master Uploader” and how it works within your diabetes management system. This guide explains what master uploader are, why they’re important, and how to ensure your data flows correctly.

What is a Master Uploader?

A “Master Uploader” refers to the primary source of data being sent to your Nightscout Pro site. This is the device or application that has the authority to upload blood glucose readings, treatment information, and other data to your Nightscout database.

In a properly configured Nightscout system, you should have only one master uploader to avoid data conflicts, duplications, or gaps in your records.

Why Master Uploaders Matter

Having a clear understanding of your master upload source is crucial for several reasons:

1. Data Integrity: Multiple uploaders sending the same data can cause duplications and inconsistencies
2. Troubleshooting: When issues arise, knowing your master upload source helps identify where the problem might be
3. System Performance: A well-organized data flow improves the overall performance of your Nightscout system

Choosing Your Master Uploader

When deciding which device or application should serve as your master uploader, consider the following:

For Closed Loop Systems (AndroidAPS, Loop, etc.)

If you’re using a DIY closed loop system:

• Let your loop system be the master uploader. AndroidAPS, Loop, and Trio/iAPS are designed to handle uploading to Nightscout efficiently.
• Disable direct uploads from your CGM app/Dexcom Share to Nightscout to avoid duplicate data.
• For Loop/Trio users: In your Loop settings, enter your Nightscout URL and API Secret to enable uploads.
• For AndroidAPS users: Configure the NSClient settings in AndroidAPS with your Nightscout URL and API Secret.

For Non-Loop Users

If you’re not using a closed loop system:

• Choose the most reliable and consistently connected device as your master uploader.
• For Dexcom users: Either the Dexcom Bridge/Nightscout Connect plugin or xDrip+/xDrip4iOS can serve as your master uploader.
• For Freestyle Libre users: Apps like xDrip+, Juggluco, or Diabox can be your master uploader. Nightscout Pro also has a direct integration with LibreLinkUp that can be used instead.
• For Medtronic users: Either Guardian Monitor (iOS Phone), xDrip+ (Android Phone) can sync data between Nightscout and CareLink. The 600 Series Uploader app (Android) can also upload data if you have an older (600 Series) Medtronic pump.

Data Flow in Nightscout

Understanding how data flows through your Nightscout system can help you better manage your uploads:

1. CGM/Pump → Uploader App → Nightscout: Your CGM sends data to an uploader app on your phone, which then sends it to Nightscout.
2. Nightscout → Follower Apps: Once data is in Nightscout, follower apps can access and display this information.

This one-way flow helps maintain data integrity and ensures all followers see the same information.

Common Master Upload Issues and Solutions

Duplicate Data

Issue: You see duplicate blood glucose readings in Nightscout.

Solution: Ensure only one app is uploading CGM data. Check settings in both your CGM app and any third-party apps like xDrip+ or Loop.

Missing Data

Issue: Gaps appear in your Nightscout data.

Solution: Check that your master uploader has consistent internet connectivity and background app permissions. Verify battery optimisation settings aren’t preventing the app from running in the background and that the uploader (master) phone isn’t running on low battery.

Delayed Data

Issue: Data appears in Nightscout with a significant delay.

Solution: Check your internet connection speed and stability. Some uploaders may also have settings to adjust upload frequency.

Incorrect Data

Issue: Values in Nightscout don’t match what you see on your CGM.

Solution: Verify calibration settings in your uploader app and check if any data transformation is happening before upload. – Nightscout can only store the data that has been given to it, so it’s highly unlikely that the problem lies within Nightscout itself.

Best Practices for Master Uploads

1. Consistent Internet Connection: Ensure your master upload device has reliable internet access.
2. Battery Management: Keep your master upload device charged or have a backup plan.
3. Regular Verification: Periodically check that data is flowing correctly to Nightscout.
4. Backup Plan: Know how to switch your master uploader if your primary device fails.
5. Documentation: Keep notes on your setup for troubleshooting purposes.

By understanding and properly managing your master uploads, you’ll ensure a more reliable and useful Nightscout experience, giving you and your care team confidence in the data being displayed.