Universal driver GRBL Arduino Zero port

[VojislavM]

Hi, everybody.

I am working on new version of Universal Unipolar Stepper Controller, and I want to port GRBL to new ARM platform. These are requirements and conclusions for the new version of the Stepper Controler: Version2. After searching I realized that it is not possible to find a microcontroller with all that features that cost under 3 USD.

After thinking, I decided to port it to Arduino Zero platform, mainly because I think it is the fastest way to do it, and Arduino Zero microcontroller has all the features I need.

If someone have done this before please share your thoughts, suggestions and repositories.

One thing that worries me is will Arduino Zero emulated EEPROM of 16KB be enough for GRBL? I read that GRBL team is working on GRBL port for ARM. Does somebody know when will that be done?

Thanks in advanced, Vojislav

[chamnit]

@VojislavM : Grbl runs very well on a 32KB flash, 1KB EEPROM, and 2KB ram micro controller. So with 256KB flash, 16KB EEPROM, and 32KB ram on the Arduino Zero's ARM, you shouldn't have any problems with capacity. That said, I'm working toward a SAMD21 port of Grbl, but it's a ways away still. Any work toward this goal (as well as the Arduino Due) is most appreciated.

[VojislavM]

Thank you for the answer. It was my mistake, I thought that AVR has more than 16KB of EEPROM, now I see that it is 1KB. Sorry for stupid question :)

Once I start to port firmware, I will put repository link here so everybody can see it.

Cheers.

[langwadt]

STMs nucleo is twice as fast and 1/4 the price of arduino zero http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/LN1847/PF260320

I have a port of GRBL running on a nucleo stm32f411 with three of these drivers: http://www.st.com/web/en/catalog/tools/PF260715

[chamnit]

@langwadt : Oh I don't doubt the STMs are more powerful at all. It's more whether that extra power is needed and if there is a certain level of ubiquity/community acceptance. Even at this point of today's ARMs, it's still not clear which one to pick and why I should pick one over another. In any case, I've been compiling a library of every Grbl ARM port I've run across. This includes your STM port and other Freescale(Teensy) ports.

[langwadt]

I don't think there is a reason to pick one over the other, they all have similar features. I just happen to use STM and a stack of four boards at ~$10 each is all you need for a 3 axis CNC.

Using the opencm3 firmware lib it might even be possible to make it somewhat portable between different manufacturers

[VojislavM]

@langwadt I saw your repository nucleo_grbl, if it is working well as you sad I will go to the STM side because I need to finish this fast. :) I think it would not be a problem to port your code to some smaller STM microcontroller, like NUCLEO-L053R8 that is more suited for this application.

Can you please share what compiler did you use, and other things to get me started. I also saw that NUCLEO-F411RE does not have EEPROM, and functions for reading and writing from and to EEPROM are empty nucleo_grbl/eeprom.c (code is commented). How did you handle that?

[langwadt]

@VojislavM I've just added a first try at simulating an eeprom with a sector of the flash and it seems to work (15min of code and a few hours of git...)

get:

https://github.com/langwadt/nucleo_grbl https://github.com/langwadt/libopencm3

install: msys - http://sourceforge.net/projects/mingw/files/MSYS/Base/msys-core/msys-1.0.11/MSYS-1.0.11.exe and arm-none-eabi/arm-elf toolchain (for example this one https://launchpad.net/gcc-arm-embedded) you might have to add path to the arm tool chain

run "make bin" in the nucleos_grbl dir to build

when you add the ST driver the nucleus board shows up as a uart and a disk drive just copy the stm_main.bin to the ST drive to program

if you can wait a few days I'm porting 1.0c to System workbench for STM32, libopencm3 seems to be much more trouble than it is worth and System workbench is a single install with proper debug based on the eclipse GUI

[VojislavM]

@langwadt Thanks for instructions, I will try this. Also, I will install System workbench, so I can test your new code in few days. Please send me repository link when you upload your now code for System workbench.

[langwadt]

@VojislavM new repository at https://github.com/langwadt/grbl_stm32 install system workbench, import project and you should be good to go

[VojislavM]

@langwadt Great, thanks. I ordered NUCLEO-F411RE and I will try it as soon as it comes. :)

[Andypos]

@langwadt Nucleo411 is very good concept. I port all to Coocox ,and compile .Work ok ,but for 100MHz I must enable HSE and HSE BYPASS. How You use SPI ? PROBE port change to PROBE GPIOC,GPIO_Pin_0 . regards

[jsmithcarlsbad]

Got Grbl 0.9j running on Arduino Zero tonight... this is a step towards porting to new hardware platform that will be available soon. New platform uses SAMD21J18 - is there any interest in "official" support for the SAMD21 platform ?

[chamnit]

@jsmithcarlsbad : Yes. Support for the SAMD21 series is on the table. While porting Grbl directly to ARM will make it faster, it won't make Grbl perform better. Grbl-ARM is a totally new firmware that overhauls just about everything and will improve performance across the board. I will not get into much more detail than that. However, please post your Grbl SAMD21 port. I'd like to see your approach to porting. I always learn a bit from every port I see.

[wrljet]

Will the STM32 port run on a NUCLEO-F401RE, or only the NUCLEO-F411RE?

[langwadt]

@wrljet It should run on the NUCLEO-F401RE when build for 84MHz and the slightly smaller RAM

[wrljet]

@langwadt What is required to use the EEPROM simulation code? I'm getting: error: EEPROM read fail. Using defaults

Bill

[wrljet]

@langwadt Sorry to be bothersome... Does your port for the X-NUCLEO-IHM01A1 work if these are set? // #define STANDARD_GRBL

define VARIABLE_SPINDLE

define PWM_SPINDLE

I don't seem to get a PWM signal coming out on any pin when I issue M3 to start the motor. Debugger shows this gets called in splindle_control.c (line 275):

ifdef VARIABLE_SPINDLE

ifdef PWM_SPINDLE

  TIM_SetCompare1(TIM3,current_pwm);

Thanks, Bill

[langwadt]

@wrljet you'll get EEPROM read fail the very first time you program a board after that it just works I've updated the code, there was an error so PWM_SPINDLE didn't work unless it was grbl pinout

you should probably put issues with my port on https://github.com/langwadt/grbl_stm32 it isn't really GRBL specific

[wrljet]

@langwadt OK, will do. I'm new to this github commenting world. :-) I did find and fix the small bug also. I'll report over on your hub.

Bill

[aqibi2000]

Any news on this port?