Optimizing GRBL Hal for Teensy 4.1

Progress

• Tested the setup at a max Feed Rate of 75000 mm/min i.e. 1250 mm/sec. (Can go faster ?)
• In order to acheive, high speeds while printing job, the acceleration needs to me high. Else it won't be able to acheive highest feed rate on execution.
• At high speeds stepper won't change the direction during job execution, solved by tuning the driver.c file
• Need to find ways to validate the results.

Structure

• grblHAL_Teensy4_inMachines is the firmware provided my InMachines.
• original_grbl_hal is the upstream version of grbl-Hal for Teensy 4.X .
• Teensy_Barebone_Test is the Hardware testing script.

Issues

• G-Code Sender can't connect to Teensy 4.1 (Solved)

  • Issue only occurs with inMachines custom firmware.
  • Current grblHal project for Teensy is able to connect.
  • Solution! setting USB_SERIAL_CDC to 1 one in my_machine.h

• Controller won't exit 'Alarm Mode' (Solved)

  • Once connected controller won't exit 'Alarm Mode'
  • Tried disabling, limit switch IOs and "$X" commands.
  • Probable Cause, E-Stop or Limit Switch Pins expect input or the controller tries to achieve "Homing".

      >>> G10 P0 L20 X0
      An error was detected while sending 'G10 P0 L20 X0': (error:9) G-code commands are locked out during alarm or jog state.
      >>> $X
      An error was detected while sending '$X': (error:79) An unknown error has occurred. Streaming has been paused.
      >>> ?
  

  • Solution! grblHAL defaults to normally closed (NC) switches for inputs, if none are connected when testing it is likely that the controller will start in alarm mode. Temporarily short the Reset, E-Stop and Safety Door4 inputs to ground or invert the corresponding inputs by setting $14=73 to avoid that.

  • If the issue persists, enable (by ucommenting) the macro T4.1_BAREBONE in state_machine.c

• Compilation Issue (Solved)-
  

  • Unable to find Teensy 4.16 version in platform IO registry.
    
  • Solution! making the following changes to the platform.ini file.

  [env:teensy41]
  board = teensy41
  platform = https://github.com/platformio/platform-teensy.git#v4.16.0
  upload_protocol = ${common_teensy.upload_protocol}
  build_flags = ${common_teensy.build_flags}
  lib_deps = ${common_teensy.lib_deps}
  

• VisiCut, generates empty gcode files (Solved)

  • Solution! Need to create a custom Laser Cutter inside VisiCut.

Current Setup

• Teensy 4.1
• TB6600 Stepper Driver
• Nema 17 Stepper Motor