LPC1768（Similar to smoothieboard） ，cannot be connected to the Klipper

[EddyMI3D]

@Sineos

(hell, am I really that old?!?)

You are not alone

[Elect]

@Sineos

我认为这种说法不正确或与我们在这里的情况无关，因为这在很大程度上取决于电路板的电气布局和使用的组件，如电平转换器、逻辑缓冲器等。

您是否尝试使用直接UART连接：

• 编译自 UART P0.3/P0.2
• 连接：

圆周率	功能	板
6	地	接地
8	TX->RX	RX0
10	RX<-TX	TX0

Yes, I tried. Still doesn’t work

Maybe this picture can provide some information

[Elect]

@mykepredko

Reading through this, I think there needs to a reset on what “RS-232” is and why you’re looking in the wrong direction. It is highly unlikely that the board you have is working with what is now called a “UART”, although the more correct term would be “NRZ serial” which works with traditional logic levels.

@mykepredko

I can’t find any references to any 3D printer controllers that have RS-232 on them and, I’m very certain something going back to 2018 would not have an RS-232 interface.

Sorry, My statement is wrong.There is no RS-232 on this board. What I want to say is NRZ serial

@mykepredko

现在，我对你的原始描述感到困惑，因为你说电路板上有一个LPC1768，它有一个内置的USB，但你说有一个USB接口和“将UART转换为USB”。你怎么知道是这种情况？

I mean CP2102 USB to UART Bridge on the board

@mykepredko

听起来您已经将Klipper刻录到2018 LPC1768控制器板中，但无法连接到控制器。您能否确认这是正确的，请描述（最好是带有图片）您如何尝试连接两个系统。您使用什么作为打印机控制器（Raspberry Pi或其他），您是使用USB还是UART连接，接线是什么？

I have tried USB and UART connections. I will provide wiring pictures later

[Elect]

I did make a mistake. When I noticed the information in the picture, I now successfully communicated with LPC1768.
uart [smoothieware.org]

You can now confirm that the LPC1768 board is working properly. I will try to refresh klipper again

[hcet14]

@Sineos

Seems kind of a strange board, since there is virtually no information available in the www.

[BUG] Pins error into BIQU BQ111-A4 board · Issue #18360 · MarlinFirmware/Marlin · GitHub might help with the pinning.
Here are also some useful informations https://www.aliexpress.com/item/32950619979.html

@Elect
Make sure you use a 12V power supply? Did you set J19 to VDD?

@Elect

I did make a mistake. When I noticed the information in the picture, I now successfully communicated with LPC1768.
uart [smoothieware.org]

Are you talking about J14 on your board?

Smoothieboards https://smoothieware.org/smoothieboard are also using the USB controller on chip. Have a look at the schematics The Smoothie Project · GitHub.

The problem seems to be the CP2101. Usually LPC1768 µCs use a direct connection to the USB connector (pins 29 and 30 for LQFP100 packages) using the USB controller on chip. With this board, you are using an UART on LPC1768. That’s a different setup!

Only chance to get that board working: Is there an LPC board which uses UART to communicate with Klipper and is supported by Klipper. Maybe then, you may be able to construct a config to get it running.

This is gonna be tricky!

Good luck, hcet14

Edit: You may check, if there is a connection between pin 29 and 30 on LPC1768 and the USB connector. Maybe the USB connector is hooked up to LPC1768 and CP2101 in parallel. I have seen many funny 3D mainboard schematics!

[bruce]

I had the same problem and found that I had to use the kiauh tool to find the mcu number and copy it and paste to the [mcu] in the configeration file