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Last active February 29, 2024 08:51
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BTT H723 Octopus Pro Errata
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BTTH723.md

BTT H723 Octopus Pro

image (2)

Update

The 1.1 version of this board fixed the DFU issue and the SPI issue has been resolved as well I've been told.

Old Information

I recently purchased this board due to the processor that's on it as well as the ability for native 48v support. For me, I run 4 motors in x/y that are 0.9 degree with 128 microsteps. At my speeds (25k+ acceleration, 550mm/s+ for my quality settings), I can overrun other boards. This board seemed like a good fit.

However, despite the good, it has a couple of issues that make it so that I cannot recommend this board to anyone.

Issue 1: Still turns on HE0 in DFU

BTT has had this issue before on their EBB 1.1 board. In that scenario they turn the hotend heater via the HE0 pin. This is an issue because it does not also turn on the hotend fan. Klipper isn't active at this point. If left unchecked, your heater can easily melt the mount that your hotend is mounted on.

This is a photo from the EBB36 1.1. image

While it's a big issue, I could understand if this happened only once. However, this is a completely separate board where it is happening months later and is simply inexcusable. BTT acknowledges this on their listing for the board. I didn't notice HE2 turn on, but I didn't have anything plugged into it when I was flashing my board. image

It's worth stressing that this is not something that can be addressed with a firmware update as the bootloader is read only on STM chips.

Issue 2: Many boards don't have the motors hooked up to the SPI bus.

This is more of a strange issue. It doesn't appear to happen to all boards, but I've talked to 3-4 other people who all had this issue and some also had it on versions other than H723 version. The SPI lines of the motor drivers aren't hooked up to the actual SPI bus of their board. UART works fine, but this means that this board would be useless for 48v with 5160s.

Luckily this can be remedied. With the help of IKirin from the Annex team, we were able to just reconnect the entire SPI bus by soldering this pad and jumping into PA6 on the EXP2 header of the board.

PXL_20230221_221221023

After this fix, it will work like normal.

Wrap up

Because of this issue, I cannot recommend this board at this time and it makes it difficult to recommend BTT boards as a category. We at Annex Engineering have decided to no longer recommend BTT boards for our users. There is too much variability and too much risk. If you decide to use their boards, please be aware. Feel free to reach out to us in our discord.

Thanks, kmobs

@tutankino
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I have h723 1.01, i tried your jumper suggestion but not working for me, 5160 SPI not working on this board

@pasha4ur
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pasha4ur commented Feb 29, 2024 •
edited

Hello

BTT Octopus pro STM32F429 started losing SPI TMC2240 after few prints. Looks like Only disconnecting display helps

Unable to write tmc spi ‘stepper_x’ register GLOBALSCALER

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