Grbl tests 2022

Autonomous · September 15, 2022, 4:13pm

It would be nice to have an 8-driver version of the 6 pack. Unlike most other controllers, the 6 pack can be easily upgraded to a newer/faster mcu. The esp32 currently supports marlin, grbl, rrf and klipper firmware could be compiled for the esp32 via platformio.

vicious1 · September 15, 2022, 4:23pm

Still with extremely limited IO, as far as I know there is no way to run 6 TMC drivers with enough IO to also plug in everything to 3D print. I would love for that and I spent a ton of time looking, but I don’t think it can happen. Pretty sure you can not run the 6 pack with Marlin for 3D printing.

Yeah, that is very low on my list. Passing thousands and thousands of boards through my hands each year I have learned that takes a dedicated company to manage that sort of thing.

vicious1 · September 15, 2022, 4:24pm

Well maybe with Klipper but that just adds another board to deal with.

Autonomous · September 15, 2022, 5:09pm

Agreed, the 5 existing expansion modules are for CNC functions only such as spindle control. There are no module designs to support 3D printing such as heaters, thermistors, bltouch and fans. I counted 12 gpio pins dedicated to CNC expansion modules in addition to endstops so it is possible enough gpio pins are available to support 3D printing. Might be worth discussing with Bart Dring.

vicious1 · September 15, 2022, 5:33pm

I did discuss some of this with him and another board manufacturer. The TMC’s are pin hogs so if you add one more driver you might as well add 3 I think, but that kills another 3-4 pins if I remember right.

We just need an esp32 v2 with more IO’s and we would be set!

What I think is a good option here and what I am trying to work out, is finding a great base board that is inexpensive and adding something like the esp32-cam board to enable headless and SD for a few bucks. I am not really seeing any practical differences in boards these days as long as it has enough drivers, and a few extra IO.

The game changer recently is finding out that GRBL runs on these current boards with no compromises. That is my bad for sure, John worked that out 2 years ago…I am just now catching up.
So now my board search has changed a bit. Price/cross “platform”/headless. That headless option is for price mainly but I am hoping that esp32cam makes all board headless capable. Just not sure if we can use the micro SD on it for reading files. My test boards show up Saturday to find out, then figure out how to connect them to the SKR and Rambo…the Octopus would be plug and play.

Autonomous · September 15, 2022, 5:54pm

Ah, I see where you are going with the esp32cam. I have a stack of cheap esp32cam boards to experiment with interfacing with mks boards. I was about ready to start working with these boards for another project anyway…

jeffeb3 · September 15, 2022, 6:55pm

The esp32 doesn’t have many IO. And the bart 6x board uses the shift register to handle a bunch of extra IO. It is easy to say that ESP32s run Marlin, but can Marlin talk to the shift register? If there was a marlin focused ESP32 board, would the chip they use to expand the IO be usable by FluidNC? And then RRF, and Klipper…

They are excellent options, and not by accident. You have been selling the rambo for years now. The Skr Pro was a deliberate choice when you couldn’t find enough rambos (Before the skr, there were archims, and you couldn’t buy them). The Skr Pros are not going to be available forever either. That’s why there was a board search in the first place.

I don’t miss the mini rambo, but I would like to have a board with just 5 drivers in a small package that can run reliable, quick CNC/Laser firmware. Some of these smaller skr boards are very useful looking.

gpagnozzi · September 15, 2022, 7:25pm

The only problem with Klipper will be with a laser module, as it has been described on github Klipper Docs under Limitations

Autonomous · September 15, 2022, 7:28pm

It does, see:

github.com

MarlinFirmware/Marlin/blob/8e71f7add45782f17ce485c6a2bd9004edac156c/Marlin/src/HAL/ESP32/i2s.cpp

/**
 * Marlin 3D Printer Firmware
 * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
 *
 * Based on Sprinter and grbl.
 * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *

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Fluidnc:

github.com

bdring/FluidNC/blob/main/FluidNC/src/Pins/I2SOPinDetail.cpp

// Copyright (c) 2021 -  Stefan de Bruijn
// Use of this source code is governed by a GPLv3 license that can be found in the LICENSE file.

#ifdef ESP32
#    include "I2SOPinDetail.h"

#    include "../I2SOut.h"
#    include "../Assert.h"

namespace Pins {
    std::vector<bool> I2SOPinDetail::_claimed(nI2SOPins, false);

    I2SOPinDetail::I2SOPinDetail(pinnum_t index, const PinOptionsParser& options) :
        PinDetail(index), _capabilities(PinCapabilities::Output | PinCapabilities::I2S), _attributes(Pins::PinAttributes::Undefined),
        _readWriteMask(0) {
        Assert(index < nI2SOPins, "Pin number is greater than max %d", nI2SOPins - 1);
        Assert(!_claimed[index], "Pin is already used.");
        // User defined pin capabilities
        for (auto opt : options) {
            if (opt.is("low")) {

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Klipper would need to be modified to support i2s pins.

vicious1 · September 15, 2022, 7:36pm

The issue is still we can’t get eh 6 pack in quantity and with all the modules we would need it would be very expense. Until there is a specific board set up as needed with a good price I don’t see any reason to pursue the 6 pack, or any other esp32 based board.

That is nuts! Thanks for that info. So we still need to just focus on GRBL, RRF, and Marlin. How Is RRF with the Raster laser? I guess I could run that test, I have a new project on my table currently though so no promises to do that right away. Heck if RRF works better than Marlin, that is a pretty easy switch I think just provide the config files right?

vicious1 · September 15, 2022, 7:37pm

P.S. I love this I feel like we are getting somewhere quickly!

kvcummins · September 15, 2022, 8:13pm

Sounds like someone needs to badger Espressif for an ESP64…

Paciente8159 · September 15, 2022, 9:37pm

I’m waiting for my MKS TinyBee board to arrive.
This is a 5x board though.
This board is supported by Bart’s FluidNC and Marlin also.

I actually bought it because recently I’ve added a few more MCU to µCNC (including basic support for the ESP32).
I want to run deeper tests on the ESP32 and try out my module for the 74H595 shift register but need I the board for that.
I’ve recently added SD card support and I am currently doing an additional module for the Reprap Full discount graphic display…but is still being developed.

Just one question. Is there a specific reason to opt for the 6x boards?

jeffeb3 · September 15, 2022, 9:59pm

That Tinybee is neat. Will it talk uart to tmc 2209 drivers?

I’m also worried about the number of endstops for 5x. I see a few extra ports, but they aren’t labeled as endstops.

Paciente8159 · September 15, 2022, 10:11pm

I don’t know if Marlin or FluidNC will talk to the TMC2209 drivers. The TX2 RX2 available pins are there to be used by the TFT (2,4" or the 3,5") I believe.

It is possible though. A single IO pin could be used to address the TMC in multislave mode, but I believe that would mean that it would be an MCU to TMC one way communication only.

tmc

The endstops are designed as X Y Z and probe.

The thing about the ESP32 and the 74HC595 is that the latest can only be used as an output IO expander and not an input IO expander. For that you still need ESP32 free pins.

vicious1 · September 15, 2022, 10:24pm

The MP3DP v4 with hardware leveling. Not really needed for CNC unless you want to be able to still 3D print and having dual squaring…which could be cool for something I am dreaming of making.

As much as I like the esp32 people seem to put in a lot of work to try and make it work. In terms of bare processor costs is it that much better than anything else? I get they are amazing hobby boards but we need more IO for 3D printers, and it can barely do a CNC.

Paciente8159 · September 15, 2022, 10:41pm

Yes they are dirty cheap and they are a dual core MCU running @ 240Mhz with Wi-Fi and Bluetooth.
The other side of the coin is that you are forced (as far as I can tell) to use an RTOS with it. The level of indirection on the ISR level is very trippy… It’s easy to make the one of the processes blow up and get a reset. And Yes very little IO. Some IO drivers are even done via internal libraries software (like the I2C or PWM on the Esp8266 I think)

I’ll be honest. In this aventure I became a big fan of Stm32 chips.
Very cheap and very well designed. All the IO and IO drivers you need… If you want wireless or BT then you can team it up with an ESP.

azab2c · September 16, 2022, 12:29am

I don’t know what’s required to reliably control steppers via TMC2209 drivers using ESP32. But, to shed light on what IO’s possible, I’ve previously supplemented ESP32 to drive 192 individual 9g Servos using a bunch of I2C based IO breakouts like PCA9685. But that was just to mess around for a tech art project. I wasn’t trying to create highly available production quality machine.

MakerJim · September 16, 2022, 2:53am

Is there good documentation of which versions of GRBL fit which systems. For example, I have a bunch of old RAMPS 1.4 and 1.6 from old 3D printers, but when I looked into getting GRBl to run on those the documentation was near impossible to follow.
Similarly, I have an old MKS Smothieware clone board and couldn’t easily figure out what to run on it.
Just reading this thread it still isn’t clear which GRBL versions to even explore.

Paciente8159 · September 16, 2022, 3:46am

You have several ports of Grbl for specific boards and/or applications.

For ramps the ones I know are:

Grbl-Mega (from the maintainer of Grbl)
Grbl-Mega-x5
Grbl-L-Mega (this is aimed at lathe control)
µCNC (not a Grbl port but is based on the same protocol)

For the MKS smoothieboard maybe:

grbl-LPC
grblHAL
µCNC (may support it by creating the respective board map file)

I think only grblHAL and µCNC are “wide spectrum” projects as in multiple MCU/BOARDS cover.