Why Can’t I Format TF Card with My Phone?¶
RecDual Dongle cannot recognize TF cards that have been formatted using a smartphone. This article explains why and how to properly format your card.
The Problem¶
When you format a TF card using a smartphone:
The phone creates non-standard partitions
Special file systems may be used for Android/iOS optimization
Hidden system folders may be created
The partition structure differs from standard computer formatting
Result: RecDual Dongle cannot read the card, and the REC LED stays off.
Why Smartphones Format Differently¶
Smartphones optimize storage for their specific needs:
Android may use ext4 or custom partitioning
iOS uses APFS-related structures
Both may create hidden system areas
Storage is formatted for app usage, not video recording
These optimizations make the card incompatible with RecDual Dongle’s firmware, which expects standard exFAT or NTFS formatting.
The Solution¶
Always format TF cards using a computer.
On Windows:
Insert card into card reader
Connect to computer
Right-click on drive → Format
Select exFAT file system
Click Start
On Mac:
Insert card into card reader
Open Disk Utility
Select the card
Click Erase
Choose ExFAT format
See How to Format TF Card for RecDual Dongle? for detailed steps.
What If I Already Formatted on Phone?¶
If your card was formatted by a smartphone:
Insert into computer using card reader
Reformat as exFAT following steps above
Safely eject from computer
Insert into RecDual Dongle
Verify REC LED turns solid green
Note
Reformatting will erase all data on the card. This is expected and necessary.
Prevention¶
To avoid this issue:
Format new cards on computer before first use
Never use phone’s format option for RecDual Dongle cards
Keep a dedicated card for RecDual Dongle use
Label your cards to avoid confusion
Summary¶
Do |
Don’t |
|---|---|
Format on computer |
Format on smartphone |
Use exFAT file system |
Use phone’s default format |
Insert card before connecting phone |
Format when phone prompts |