FEDEVEL
Platform forum

Anik , 11-27-2024, 03:31 PM

Hi,
I was trying to make a device which willbe plugged in on a phone always. And there willbe a SD card. There is a card reader IC, USB data line mux and two USB C male and female port. When the device willbe plugged in to a phone the phone will show the storage. After that when I plug in the USB cable then card reader dataline willbe switched to USB cable, so I can access it by PC.
The device is not working. Non of side can detect the sd card. I am using 16GB SD card.
I am open to change the design. If any better idea found.
Thank you.
Anik

Anik , 11-27-2024, 03:32 PM

Datasheet of both used IC

QDrives , 11-27-2024, 04:59 PM

Does the card reading work without mux?

Anik , 11-27-2024, 05:51 PM

The pin is too small so its almost impossible to wire over the mux to the card reader.

Robert Feranec , 11-27-2024, 06:26 PM

I agree with @QDrives , cut the tracks going to the usb card reader chip and connect USB cable directly there. If it works, go one chip up.

QDrives , 11-27-2024, 07:57 PM

No need to cut tracks. Just wire directly from the 'PC' connector to the SD card chip.
If the PC does not see anything then either:
- the PC usb connector was wires incorrectly
- The SD card chip does not work.

Anik , 12-02-2024, 10:49 AM

The main problem is with the mux. I have wired the power pin to the VBUS.
But not working with phone only. Only worked for PC.

Anik , 12-02-2024, 10:54 AM

Or maybe my expected functions are not working on the wiring I made on the schematic with the MUX IC.

QDrives , 12-02-2024, 02:27 PM

Check the pinout of the USB connector to the phone.
Then wire directly from that to the SD card chip.