TUSB2046B: Problems with an optical USB-mouse.

What does "it doesn't work" mean? What exactly fails? The mouse, the hub, or the entire system?

Please show a schematic of the circuit, especially of the hub's power supply.

Hello Clemens,

if I insert the mouse connector, the mouse LED is on for a short time and is blinking.

Than it switches off for the rest of the time.

On the TOUCH-display is NO reaction of the mouse movement!

Greetings

Harald

If the USB stick still works with the mouse present, then it's a software problem.

Hi Harald,

Do you get any error messages from the host?  Can you check that the VBUS at the port doesn't dip below 4.5V?  Does the mouse work when the flash drive is not used?  Can you try another mouse or keyboard?

Regards,

JMMN

Hi JMMN,

thank You very much for trying to help me.

At first, I want to tell You from a test I made last week:

I removed R27 and R28 from my board and contacted there directly a USB-type A-socket.

I plugged in the USB-stick. It worked very well. I removed the USB-Stick and plugged in the optical mouse.

It also worked very well.

Now to Your questions:

1. I didn't get any error massege from my host (Raspberry-Pi compute module 3+ with raspbian-OS).

2. I checked the VUSB-voltage at C34 with several mice. There was a break-down appending to each mouse.
    Mouse 1 (Dell silver) 1.6 V for 217 ms
    Mouse 2 (Dell black) 4.1 V for 34 ms
    Mouse 3 (Hama)       2.1 V for 195 ms

3. The mice are never working with or without a flash drive.

4. Neither the  3 mice, nor a keyboard are working.

Another test:

I made a wire bridge from C3 (+5V) to C34 (VBUS at X15 (USB-A-1) and plugged in ther the mice.

Once more, the mice are NOT working.

Regards

Harald

Hi Harald,

The VBUS voltage needs to be over 4.5V for the devices to connect properly.  What is the VBUS voltage when a flash drive is connected?  Can you check the traffic on the DP/DM lines on the downstream port?

Regards,

JMMN

Hi JMMN,

sorry for the late answer. I was out of my office.

Here are my measurements:

- VUSB without any USB-device: 4.84 V

- VUSB with flash drive: 4.81 V

-VUSB with optical mouse (after negative pulse): 4.80 V

I'm sorry, but I haven't any instruments to check the USB-traffic.

Regards

Harald

Hi Harald,

Can you just check the DP / DM linestates?  Why is there a negative pulse on VBUS, you have a lot of bulk capacitance in-rush current should not be an issue.

Thanks,

JMMN

Hi JMMN,

sorry for the late answer. I was out of my office.

I made some oscillograph curves.

The different channels were:

• CH1: VBUS at C34, pin 1

• CH2: DP at R48 pin 1
• CH3: DM at R50 pin 1

1. oscillograph curves when the mouse-plug is inserted

1.1 complete oscillograph curve

1.2 zoomed oscillograph curve part 1

1.3 zoomed oscillograph curve part 2

1.4 zoomed oscillograph curve part 3

1.5 zoomed oscillograph curve part 4

2. oscillograph curves when the USB-flash drive is inserted

2.1 complete oscillograph curve

2.2 zoomed oscillograph curve part 1

2.3 zoomed oscillograph curve part 2

2.4 zoomed oscillograph curve part 3

2.5 zoomed oscillograph curve part 4

2.6 zoomed oscillograph curve part 5

Regards

Harald

Hi Harald,

Very strange.  Can you trigger on the rising edge of DP when the mouse is connected and zoom in?  I would expect the scope plot to look like this (yellow - DM, red - DP)

Thanks,

JMMN

Hi JMMN,

I tried to trigger on DP, but there is NO action at this Signal when I connect the mouse.

Only at DM the signal is changing.

Regards

Harald

Hi Harald,

Could you zoom in on the DM pulses with the mouse?  I'd like to check the timing.  Another possible cause could be all the bulk capacitance on the board.  Typically, lots of bulk capacitance is great for preventing in-rush, but it could be resulting in a incomplete power cycle / reset to the mice. 

Regards,

JMMN

Hi JMMN,

I made some oscillograph curves.

The different channels were:

CH1: DP at R48 pin 1
CH2: DM at R50 pin 1

1. oscillograph curves when the mouse-plug is inserted

1.1 complete oscillograph curve

1.2 zoomed oscillograph curve part 1

1.3 zoomed oscillograph curve part 2

1.4 zoomed oscillograph curve part 3

1.5 zoomed oscillograph curve part 4

1.6 zoomed oscillograph curve part 5

1.7 zoomed oscillograph curve part 6

1.8 zoomed oscillograph curve part 7

1.9 zoomed oscillograph curve part 8

1.10 zoomed oscillograph curve part 9

1.11 zoomed oscillograph curve part 10

1.12 zoomed oscillograph curve part 11

1.13 zoomed oscillograph curve part 12

Bulk-capacitors:

Therefore I used the Capacitor F910J107MAAAJ6 from AVX

datasheets.avx.com/F91.pdf

Regards

Harald

Hi Harald,

How many boards are you seeing this issue on?  What does the PCB look like?

Also, can you accept my friend request so we can discuss directly.

Regards,

JMMN

Hi JMMN,

I've built-on 2 boards. 

Both are showing the same behaviour.

Here are the photographs of my board.

1. complete module

2. Problem board with the USB-hub

3. PCB-Layout: Top layer of the board with GND-plane

4. PCB-Layout: First inner layer of the Board with GND-plane

5. PCB-Layout: Second inner layer of the Board with +3,3_RasPi-plane

6. PCB-Layout: Bottom layer of the board with GND-plane

By the way: I've accepted Your friend request.

Regards

Harald

HI Harald,

Thanks for the photos, I just sent you a direct message.

Regards,

JMMN

Same issue seen with TI EVM, appears to be a rasberry pi support issue.

Regards,

JMMN