[FR] Raspberry Pi Pico

[Doyle4]

Hello,

Will the Raspberry Pi Pico be supported in the future?

Thanks :)

[thawkins]

This beast has 16 pwm and pulse train generators built in, it should be capible of very high step rates.

[ellensp]

A nice fairly unbiased comparison to other commonly available chips
https://www.youtube.com/watch?v=cVHCllbN3bQ

[panchalnikunj]

https://www.youtube.com/channel/UCA4j-J-TFW_9Dt4iTwIjtYQ

Once visit this channel for raspberry pi pico projects.

[KillerBug]

I built one. It's a Delta with a 3-in-1-out effector...so 6 stepper drivers. Running the thermistors into the stock ADC to see if it's good enough. If not, there is an i2c header that could be used for a different ADC (and maybe a pendant).

It's on a custom board...it has a few issues but I don't want to spin a new one before I know if the stock ADC will work (if not, I'll include something onboard in the next revision).

At the moment my problem is getting marlin to compile for it. The people over at the marlin forum say I need a new HAL, but I have no idea how to even start with that.

Happy to alpha/beta test.

Here's the post from the Marlin forum with my config files: https://reprap.org/forum/read.php?415,882792

https://ibb.co/tKhKm8V

[Hedda]

This is more interesting now that Raspberry Pi Foundation started selling RP2040 MCU to other board manufacturers for $1 US:

https://www.raspberrypi.org/blog/raspberry-pi-rp2040-on-sale/

https://www.cnx-software.com/2021/06/01/buy-raspberry-pi-rp2040-one-dollar/

https://www.tomshardware.com/best-picks/best-rp2040-boards

https://blog.arduino.cc/2021/01/20/welcome-raspberry-pi-to-the-world-of-microcontrollers

https://docs.arduino.cc/hardware/nano-rp2040-connect

https://learn.adafruit.com/adafruit-feather-rp2040-pico

Marlin Firmware core developers would first need to add a HAL for this new "RASPBERRYPI" platform which could support RP2040, (and later also future MCUs in that series that based on a similar architecture), then you can add support for each board based on that MCU.

https://github.com/MarlinFirmware/Marlin/tree/2.0.x/Marlin/src/HAL

One of the prerequisite is normally that there is already support for that platform by PlatformIO, and PlatformIO at least now look have platformio platform-raspberrypi platform suppport for RP2040 on Raspberry Pi Pico and Arduino Nano RP2040 Connect boards:

https://github.com/platformio/platform-raspberrypi

https://github.com/platformio/platform-raspberrypi/blob/develop/boards/pico.json

https://github.com/platformio/platform-raspberrypi/blob/develop/boards/nanorp2040connect.json

https://docs.platformio.org/en/latest/platforms/raspberrypi.html

https://docs.platformio.org/en/latest/boards/raspberrypi/nanorp2040connect.html

https://docs.platformio.org/en/latest/boards/raspberrypi/nanorp2040connect.html

https://docs.platformio.org/en/latest/boards/#raspberry-pi-rp2040

https://docs.platformio.org/en/latest/boards/raspberrypi/pico.html

https://docs.platformio.org/en/latest/boards/raspberrypi/nanorp2040connect.html

PS: Suggest maybe raise this as a feature request/suggestion to the Raspberry Pi Foundation (as well as well as to their Raspberry Pi Community) as would think that it would also be in their interest to have support for RP2040 and Pico boards in Marlin Firmware. Should be very cool to start seeing different RepRap 3D-printer custom boards built based on RP2040 MCU natively or breakout boards using Raspberry Pi Pico and Arduino Nano RP2040 Connect running Marlin Firmware.

https://www.raspberrypi.org/

[CaptainNico54]

I am looking at developing a new board using the RP2040 (Pi Pico) and I am looking for Marlin support.

Now that the MCU is fully supported by Arduino and Platform.io, what would we need to do to get the Marlin team to add support for this?

[thinkyhead]

Here is a basic starting-point that I "quickly" cobbled together… https://github.com/thinkyhead/Marlin/tree/bf2_RP2040_target_PR

The HAL code is simply a copy of HAL/STM32 with slight modifications. I picked HAL/STM32 because Malyan M200 has an ARM Cortex-M0 and uses HAL/STM32 so it ought to be pretty close. Pretty much all the functions. methods, and macros in HAL/RP2040 will need to be modified with code appropriate to the RP2040.

[pkElectronics]

Based on the previous work from @thinkyhead and @p3p I started implementing the required macros and functions on my own fork.

If someone want´s to have a testdrive have a look at https://github.com/pkElectronics/Marlin/tree/pr_RP2040
But beware, it´s absolutely work in progress and probably will not yet work as expected.

[pkElectronics]

Alright, I wanted to give a short update on this.

I finished the implementation of the most basic Marlin subsystems (Analog, Timers, Watchdog) and some more advanced (TMC Uart, SoftSerial). It compiles and is able to move steppers on a rp2040 based control board. If someone wants to have a look please check the branch I provided above.

I´m not yet sure if the way I implemented the timer subsystem is the best approach to this topic but by now it´s the best one I came up with. The timing of the stepper pulses definetly needs some verification if this is as accurate as necessary.

[terjeio]

The timing of the stepper pulses definetly needs some verification if this is as accurate as necessary.

You may use PIO code for pretty accurate timing.

[thinkyhead]

… If someone [wants] to have a testdrive …

I got pretty far in compiling the code, rebased with the current bugfix-2.0.x but it stalls because I need to install LVGL someplace. I assume it'll build for a Linux-like target.

You may use PIO code for pretty accurate timing.

We will seldom need to send pulses in the way that this facilitates. The pulses out of Marlin are tied to the Bresenham algorithm, so they are interleaved in an irregular manner, and also spend a majority of the time in acceleration / deceleration.

[AlexFroio]

Adding onto this thread so I don't make a new one, but a pico based board has been released by BIQU:
BTT SKR Pico v1.0

It's aimed at Klipper but can still benefit from a Marlin port.

This may make it easier to test on actual hardware without making custom boards.

Edit:
Updating to add the SKR Pico Github link