# Connection lost using 2 webcams on RPI 3B

**URL:** <https://klipper.discourse.group/t/connection-lost-using-2-webcams-on-rpi-3b/15134>\
**Category:** General Discussion\
**Created:** [March 22, 2024, 9:29am UTC](https://klipper.discourse.group/t/connection-lost-using-2-webcams-on-rpi-3b/15134 "2024-03-22T09:29:37Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Ashen](https://avatars.discourse-cdn.com/v4/letter/a/3bc359/32.png) [@Ashen](https://klipper.discourse.group/u/Ashen)\
**Post date:** [March 22, 2024, 9:29am UTC](https://klipper.discourse.group/t/connection-lost-using-2-webcams-on-rpi-3b/15134/1 "2024-03-22T09:29:37Z")

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### Basic Information:

Printer Model: Creality CR-10 V2 with bltouch  
 MCU / Printer  
[klippy (1).log](https://klipper.discourse.group/uploads/short-url/hHrA8pOI8Rh3sHlqlOXYFZNAIu8.log) (3.3 MB)  
board: atmega2560 / Printerboard: Creality 2.5.2  
 `klippy.log`

### Describe your issue:

When running two webcams (Logitech C920 via USB + PiCam 2) on my RPI 3B with a Klipperscreen, the connection gets interrupted during printing. All runs well if I only use the PiCam2. Is the RPI hardware causing this propably?

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**Author:** ![gaolst](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/gaolst/32/10026_2.png) [@gaolst](https://klipper.discourse.group/u/gaolst)\
**Post date:** [March 22, 2024, 10:03am UTC](https://klipper.discourse.group/t/connection-lost-using-2-webcams-on-rpi-3b/15134/2 "2024-03-22T10:03:43Z")

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Most probably you drawing too much current.  
You can try to add external USB Hub with external power and connect cameras there.

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**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\
**Post date:** [March 22, 2024, 10:21am UTC](https://klipper.discourse.group/t/connection-lost-using-2-webcams-on-rpi-3b/15134/3 "2024-03-22T10:21:00Z")

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Sometimes a hub helps.

General experience is that USB webcams can be (in fact, are) problematic in Klipper. Exact reason is unknown:

- Too much current
- Too high data rates
- Other effects that causes timing issues on the USB bus

The effect is often depending on the camera model.

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/klipper/original/1X/64419bf2aac6639e6ef5cef200dcd456b0a01ac3.png) [@system](https://klipper.discourse.group/u/system)\
**Post date:** [May 21, 2024, 10:21am UTC](https://klipper.discourse.group/t/connection-lost-using-2-webcams-on-rpi-3b/15134/4 "2024-05-21T10:21:48Z")

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Closed on May 21, 2024, 10:21am UTC

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