UART vs SPI on 3D Printers. What are they?

What is the difference between UART and SPI and does it matter on 3D Printers? Configuring control boards and firmware can be a highly complex and confusing endeavour. knowing the difference between UART and SPI and how to configure each can be a critical step to ensure you can enable the stepper driver features you want.

Thanks to BIQU for providing the BTT GTR V1.0

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[Spartacusse]

UART has some nice features for people who are into tinkering, like dynamically switching from spreadcycle and stealthchop2 modes. But I think what most people will use, if they do, is being able to change the driver Vref in the firmware and not by turning the potentiometer.

[kwaad]

Very good explanation on the two technologies, and explaining the application and advantages. (or total lack thereof) between the two. Thanks for the video!

[RobbieHatley]

Excellent video; thanks for making and posting. I was interested in how SPI works, but the first few videos I looked at that claimed to be about connecting a CPU (Arduino, ESP32, Pi, Teensy, etc) to a TMC5160 stepper driver had "SPI" in their title, but skipped actually describing how to hook it up. Thanks for the detailed description!

[Srabh]

My friend, this is what I wanted to know but did not bother to search for. Subscribed for this video.

[rayams]

Thank you so much for sharing this info - in fact, these were confusing to me as well.

[machinerin]

Fun fact: GTR board, when taken with an expansion board and filled with UART TMC2209 drivers - costs almost as much as a Duet 2 + Duex5 clones from the same Bigtreetech. It has more inputs and outputs, if you plan to use Klipper - it's a pretty good system, could be worth it, maybe for something like a Voron or other printer with lots and lots of motors.
If you do like Reprap firmware, and don't mind its restrictions and lower speeds - you can get a Duet clone.

Either way - Bigtreetech has got you covered. I like what they're doing. Affordable prices, true open-source on github...
I wish Bigtreetech made their own Pi board! You know, to order alongside the other boards, for octoprint and other similar things.

[Sonny]

ramble ramble ramble/ Loves the sound of his own voice.

[gundy]

At 4:28 seconds I found myself asking out loud, what the hell does any of this have to do with SPI or UART.

[garramiro]

remember on my embedded systems class learning about UART, i have now forgotten almost everything lol.

[roeidalm]

Thanks so much! now i understand the different!

[leandrodibuono]

Ótimo vídeo, usei as legendas. Deu pra entender certinho. Obrigado.

[plampix]

Do keep in mind that, if you want to use UART for your stepper drivers, the microcontroller will probably not have that many UARTS supported in hardware, and a software implementation must be used (which will probably be slower/require more resources/be less reliable), whereas with SPI, you only need one SPI bus on your microcontroller (of which there may be more than one)

[lautaro-busto]

this came just in time, im about to upgrade my printer's board and drivers, and i really confused about spi/uart

[datrandomdugggy]

so does uart set microstepping or do i need use step/dir mode to get microstepping?

[alfredanil]

Is there a way to add ethernet to octopus board instead of wi-fi? Probably a ethernet breakout board with UART or SPI interface. Looking to connect my RPi remote server to 3d printer.

[szekerespista]

The UART mode is not supported on SKR 1.2 PRO board?

[MarkusFotofieber]

AFAIK boards like SKR 1.4 use only one pin for RX and TX with TMC drivers in UART mode.

[geraldblindeling]

Hi can you make a video how to setup this board for it to compile propely with no error thx.

[Bajicoy]

Me: I don't understand the difference
Vector3D: this is how to understand the difference
My brain: no, I don't think I will

Really nice video guide, I will rewatch this in a little bit after I figure out the wiring for TMC2130 to RAMPS to fix some cetus printers.

[cameronmalchow]

Almost a good video, but you very much ignored the software difference between the two. Specifically the added features you get with Marlin when you use UART as the communication type on steppers that support it. Added features like being able to specify the current, turn on/off the various modes and set thresholds for modes. This is a lot more than you can currently do with the SPI connection in Marlin.