Thank you!

[norru]

Hi @labsud,

I am trying to build my own CNC machine as a semicustom WorkBee design using the Due and g2core.

I was thinking of designing my own from scratch but found your work here instead, which looks like an awesome starting point.

I am planning to use inexpensive TB6600 drivers which require 5v signal levels. Due spits out 3.3v and although the TB6600 I intend to use may be tolerant to 3.3v inputs, I've read around that it's not good practice.

In your design I haven't seen any level shifting components (but you have a driver power config 3.3v-5v?) so I guess you went with the "drivers will be ok" mindset.

Did it work for you? Otherwise I might want to tweak your shield to add level shifting to the motor control pins.

Thanks
Nico

[ewidance]

HI Nico

As you can see in the schematics (https://github.com/labsud/GTwo/blob/master/GTwoShieldSchematics.pdf) there is a bidirectional level translator, used for 6 endstops, interlock and Estop inputs. But it does not work properly for two reasons:

• Choosen translator is bidirectionnal, and use "less impendance" method to autodetermine witch pin is the input for a group of 4 inputs. Depending to what is connected to inputs, level translator can make a bad guess, reverting loginc.
• TinyG2 doens not have a proper debbounce logic. It is necessary to add an R/C circuit for making hardware debbouce.

Becasue that was a one shot project, i did not update the PCB on github, but my prototyê wa updated to remove the level translator and replace it with a R/C filter. I did not implement level shifting logic all my inputs where powered wit 3.3V.

Outputs are directly wrapped to stepper drivers. Yes, outputs could also be improved using for example non inverting buffers or level shifters for improving noise immunity and giving enough energy to opto on drivers.

I stopped to work with G2 when software team started to go to G2Core. This massive update broke almost totally usage. That was especially true for the modifications i've made (and suggested) for COreXY kinematic.

I did not recently used G2, and maybe 3 years after it is back to a working level...

Finally the machine used for G2 have been converted to GRBL STM32 (https://github.com/usbcnc/grbl and https://github.com/dungjk/grbl-stm32).

My final advice, would be first to carfully check status, bugs and fonctionning ov TinyG2 before developping a board...

Sincerely
JP CIVADE

[TheAnsgar]

Hi,

do you know why the shield doesn't work anymore with g2core?
Isn't it just a matter of configuring the pinouts?

Kind regards
Ansgar