Connecting a flash drive to the smartphone Xiaomi Redmi Note 9 Pro seems to be a simple task, but in practice users are faced with nuances: the lack of a connector USB-C before-reading errors MIUI. In this article, we will analyze all the current methods - from the classical OTG-cable to wireless solutions, and explain why a smartphone may not see the drive and how to fix it.
Redmi Note 9 Pro (codenamed Joyeuse) USB OTG "It's out of the box, but it requires the right adapter and system setup to work properly. MIUI 12–14 (Android 10–13) and identified key points: from file system formats (FAT32, exFAT, NTFS) If you want to move movies, backups or documents, read on.
1. Compatibility check: which flash drives are suitable for the Redmi Note 9 Pro
Not every flash drive will work with a smartphone.
- 🔌 Connection interface: only USB Type-A (through OTG) or USB-C (If the flash drive with a Type-C connector, Micro-USB or Lightning ports are incompatible without adapters.
- 💾 Redmi Note 9 Pro officially supports FAT32 (up to 32 GB and exFAT (up to 2 TB). NTFS Works only with root rights or third-party applications.
- ⚡ Read/write speed: for 4K-video recommended USB 3.0/3.1 (blue-jack). USB 2.0 (Black is suitable for documents and music.
- 🔋 Food: Some flash drives from LED-High energy consumption or indicators may not be required OTG-feed-in.
Critical note: flash drives with a capacity of more than 128 GB are often formatted by the manufacturer in the NTFS, which MIUI It does not recognize without additional software. Before buying, check the specifications of the drive or reformat it to exFAT via a PC.
| Type of flash drive | Compatible with Redmi Note 9 Pro | Notes |
|---|---|---|
| USB 2.0 (FAT32) | ✅ Yes. | Max. capacity 32 GB, speed up to 480 Mbit / s |
| USB 3.0 (exFAT) | ✅ Yes. | Recommended option for files >4 GB Up to 5 Gbps speed |
| USB-C (FF) | ✅ Yes. | Adapter required USB-C → USB-A (female) |
| MicroSD in the adapter | ❌ No. | Only through the card reader with OTG-support |
| NTFS (rootless) | ❌ No. | Paragon App Required NTFS analogue |
If you use a flash drive from other devices (such as a camera or set-top box), pre-check it on a PC. ext4 or other systems that are not readable by Android.
2. Method 1: Connecting through OTG-cable (most reliable)
The classical method using OTG-The adapter (On-The-Go) runs on all firmware Redmi Note 9 Pro:
- 🔗 OTG-plug-in USB-C (male) → USB-A (female).
- 💽 Flash drive with supported file system (FAT32/exFAT).
Step-by-step:
- Connect. OTG-port USB-C smartphone.
- Put the flash drive in the connector. USB-A adapter.
- A notification will appear on the screen "USB-The drive is connected.
- Select "Use as a media device" (or "Transfer files" in new versions). MIUI).
- Open "Conductor" (Files) → section "USB-accumulator".
Challenges and solutions:
- ❌ The USB drive is not defined: check the cable (some cheap) OTG Try connecting via an externally powered hub.
- ❌ The “wrong format” error: reformat the flash drive to exFAT on PC.
- ❌ Slow data transfer: use a flash drive with an interface USB 3.0 and high speed cable.
Check the flash drive file system (FAT32/exFAT)
Use the original. OTG-Xiaomi cable or certified cable
Turn off battery savings for the "Conductor"
Update. MIUI last-minute-->
If the smartphone is writing "USB-The device is not supported, try it:
- Reboot the phone.
- Connect the flash drive to another device (PC, laptop) – if it does not work there, the problem is in the drive.
- Enable the developer mode and activate the option "Debugging by" USB" (Sometimes helps with mistakes. OTG).
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If you often connect flash drives, buy OTG-cable with built-in slot for MicroSD – this will eliminate the need to carry a separate adapter.
Method 2: Wireless connection over Wi-Fi (for large files)
If you don't. OTG-You can't detect the cable or the flash drive, you can transfer files over a local Wi-Fi network:
- 📶 Router or Direct Access Point (Wi-Fi Direct).
- 💻 Computer or laptop with access to a flash drive.
- 📱 Mi File Manager (pre-installed) or Solid Explorer.
Instructions:
- Connect the flash drive to the PC and make sure it is identified.
- On PC, open access to the folder with files over the local network: Windows: PCM by folder → Properties → Access. → Sharing. Mac/Linux: Use samba or NFS.
On your smartphone, connect to the same Wi-Fi network.
Conductor
"Network"
Copy files from the flash drive to the phone.
⚠️ Note: Wi-Fi transmission speed is lower than over OTG (max. ~10-15 MB/s vs 40-80 MB/s. For movies in 4K HDR Large archives are better to use cable.
| Method | Speed. | Pluses | Cons |
|---|---|---|---|
| OTG-cable | 40-80 MB/s | Instant connection, no dependency on the network | We need cable, FS restrictions |
| Wi-Fi (SMB) | 5-15 MB/s | Don't need it. OTG, work NTFS | Slower, requires a PC |
| Cloud (Google Drive) | 1-10 MB/s | Access from any device | Traffic restriction, slowly |
Alternatively, a flash drive with built-in Wi-Fi (such as the SanDisk Connect or Kingston Wi-Drive) creates its own access point to which the smartphone connects, which is comparable to normal Wi-Fi, but the price is higher.
4. Method 3: Connecting through USB-hub (for multiple devices)
If you need to connect not only a flash drive, but also a keyboard, mouse or external hard drive, use USB-hub OTG. This method is relevant for:
- 🖥 Connections HDD/SSD (need an externally powered hub!).
- 🎮 Use of the gamepad or MIDI-keyboard.
- 🖨 Seals on USB-Printer (limited support in the MIUI).
How to connect:
- Buy a hub with a port. USB-C (For example, Baseus 4-in-1 Anker 341).
- Connect the hub to the smartphone, then insert the flash drive into one of the ports.
- If you have a power supply, then connect it to the power supply. HDD!).
- On the phone will appear a notification about the connection of the drive.
⚠️ Note: Redmi Note 9 Pro does not support UASP (Accelerated data transfer protocol, therefore the speed of operation with HDD The hub will be lower than on PC.
If the hub is not defined:
- Check if he's supporting it. OTG (Not all hubs work with smartphones!).
- Connect the hub to charging – some models require additional power.
- Update the firmware MIUI Up to the latest version (old versions had bugs with the USB-hub).
What are the main features of the Redmi Note 9 Pro?
5.The solution to the problems: why the Redmi Note 9 Pro doesn't see the flash drive
Even with the right connection, the flash drive may not be detected. Let's consider typical errors and how to fix them:
| Mistake. | Reason. | Decision |
|---|---|---|
| "USB-device is not supported" | Lack of nutrition, incompatible FS | Use a powered hub or reformat to exFAT |
| The flash drive is determined, but the files are not readable | Damaged FS or broken sectors | Check out the chkdsk /f on a PC, then format |
| Connection is interrupted in 10–30 seconds | Battery savings shuts down USB-port | Add "Conductor" to optimisation exclusions |
| "Incorrect format when connected NTFS | MIUI supportive NTFS rootless | Install Paragon. NTFS & HFS+ Play Market |
If the flash drive worked before, but Suddenly stopped being defined:
- Check the port. USB-C For debris or damage (clean your toothpick carefully).
- Test the flash drive on another device – if it doesn’t work there, the problem is the drive.
- Reset the "Storage and Storage" settings USB" Settings menu → Annexes → Application management → Three points. → Resetting settings.
For port diagnostics USB-C:
- Connect your smartphone to charging – if it doesn’t charge, the port is damaged.
- Try another cable - sometimes the contact issues are.
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If the flash drive is formatted in NTFS It's not readable, so don't rush to reformat it. Install the Paragon app. NTFS — adds support NTFS rootless.
6.Alternative methods: cloud storage and FTP
If a physical connection is not possible (for example, a broken port) USB-C), Use cloud services or FTP-server:
- ☁️ Google Drive / Mi Cloud: Upload files from a flash drive to your PC to the cloud. On your phone, open the Google Drive app and download files.
Limitations
FTP-PC-server
- Install on a FileZilla Server or Python PC FTP-server (pyftpdlib).
- Use Solid Explorer on your phone or FX File Explorer for connecting by FTP.
Pluses
For FTP-connection:
- On the PC, run it. FTP-server (for example, via python) -m pyftpdlib -p 2121).
- Find out locally. IP-PC address (ipconfig) in Windows).
- Add a new one to your phone in Solid Explorer FTP-join IP port.
- Copy files from a flash drive (connected to a PC) to your phone.
⚠️ Attention: when transmitting by FTP Turn off traffic optimization in the settings MIUI (Settings → SIM-maps and mobile networks → Transfer of data → Optimize traffic, otherwise the speed will fall to 1-2 MB / s.
7.Security: How to protect data when connecting a flash drive
Connecting third-party drives to a smartphone carries risks:
- 🦠 Viruses: Flash drives often become malware carriers (for example, Android.Triada or Adware).
- 🔓 Data leak: if the flash drive was in a public place (Internet cafe, library), it may remain access keys.
- 🗃 Loss of files: if improperly extracted, damage to the FS is possible.
Safety recommendations:
- 🛡 Install an antivirus (such as Dr.Web or Malwarebytes) and scan the flash drive before opening files.
- 🔒 Turn off auto-start media files: Settings → Annexes → Auto-start → Disable for "Files".
- 🚫 Do not connect flash drives from unknown sources (especially with executable files.apk,.exe).
- 🔄 Always use Safe Extraction (in notifications) MIUI There's a "Disable" button. USB-accumulator").
If the flash drive had confidential data (for example, from work), before connecting to the phone:
- Copy the necessary files on the PC.
- Format the flash drive in exFAT.
- Transfer only the necessary files (without service folders like System Volume Information).
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Create a folder on your phone. Download/External and set up Explorer so that all files from the flash drive are copied by default to that, which will make it easier to find and protect against accidental deletion.