Want to run Klipper w/SKR Mini E3 and Old Android Phone

General Discussion
1

Basic Information:

Printer Model:
MCU / Printerboard:
Host / SBC
klippy.log

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Describe your issue:

-I have an old android UMX (U696CL) phone - USB-C connector

-I have an ender 3-pro with BIGTREETECH SKR Mini E3 V3.0 Motherboard
Micro-USB Cable

I would like to migrate from Marlin to Klipper. First I need to make a docking cable so I can have a charger and also transmit/receive data from the BTT SKR mini. Can someone show me the pinout for the cable?

What would be the simplest way to set to get klipper running on my equipment. I can change it up later once I have everything working.

Thank You

2

It has been done…

First hurdle is DC power to the phone. Most phones will NOT charge from the USB port when OTG is in Host mode. Are you willing to mod your phone battery to charge from another source?

3

I have an alternative to the charging problem, a Bluetooth to USB module (anyone know of a good module?)…

4

Wouldn’t it be a lot easier to get a powered USB Hub that can charge the Android phone and provide a link to the SKR Mini E3? No need to make your own cables.

5

Most phones will NOT accept charge when the OTG USB port is in “Host” mode as they DELIVER 5v to power flash drives or card readers.

I don’t think serial over bluetooth has enough bandwidth to connect klippy to a MCU board. Be an interesting experiment if one had spare hardware on hand and didn’t have to take a main printer offline.

Would need to be hardwired to the MCU board and Klipper frimware would need to be built to reconize serial not USB…

6

@AJS indicated that the phone had a USB C port which can be charged while acting as a host - this is an important feature of USB C.

There are lots of USB C “multiport” hubs that allow device charging while acting as the host device:

Here’s a video that shows a hub that plugs into a host device, provides a charging path as well as sockets for multiple peripheral devices: