RemRam

RemRam

Release status: working

Description	RemRam 32bit Board
License	CERN OHL version 1.2 [1]
Author	User:Nils Hasenbanck
Contributors
Based-on	-
Categories	electronics ;
CAD Models	https://github.com/hasenbanck/remram/tree/master/PCB/packages3d
External Link	https://github.com/hasenbanck/remram

RemRam 32bit Board für Marlin V2.0

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Features

• 32bit STM32F765VI

       216 MHz
       512 KBytes RAM
       2 MBytes flash

• 4x TMC2130 stepper driver

       stealthChop
       spreadCycle
       coolStep
       stallGuard

• 24V main power rail

       heatbed output (15A)
       heater output (5A)
       stepper driver and logic (5A)

• 5V secondary power rail (3A)

       FAN1 and FAN2

• 2x 3.3V tertiary power rail (2x 0.5A)

       MCU power (IO)
       SD card power

• Robust connectors
• Quality, high powered MOSFET
• 4 layer board with single side component placement

PCB design

Software used KiCad 5.0

Alternative Parts

You can substitute the TPS5408 with a TPS5402. In this case you also need to replace R4 with a Zero Ohm resistor.

Compiling the firmware

• Install Arduino
• Install the STM32 Core
• Optional: Update the STM32 Core using the git repository
• Download the current git branch of Marlin 2.0
• Open the Marlin project, select the "RemRam V1" board from the Marlin menue, edit the Marlin configuration file and build the project. You need to find the HEX or BIN file that Arduino creates and flash the firmware onto the board (See: "How to flash the firmware").

Configure Marlin

Following change is needed, until a bug is fixed:

Marlin/src/HAL/HAL_STM32/HAL_timers_STM32.h:

 #elif defined STM32F7xx
 #define HAL_TIMER_RATE (F_CPU/2) // frequency of timer peripherals
 #ifndef STEP_TIMER
   #define STEP_TIMER 2 // <- Was originally "5"
 #endif
 #ifndef TEMP_TIMER
   #define TEMP_TIMER 7
 #endif
 #endif

These are the board specific Configuration.h changes:

#define SERIAL_PORT 1 // 1 = UART connection on EXT3
                      // -1 = Serial over USB (see: Virtual COM Port Support (Serial over USB))
                      // You can also configure SERIAL_PORT_2

#define BAUDRATE 115200
#define MOTHERBOARD BOARD_REMRAM_V1

#define X_DRIVER_TYPE  TMC2130
#define Y_DRIVER_TYPE  TMC2130
#define Z_DRIVER_TYPE  TMC2130
#define E0_DRIVER_TYPE TMC2130

#define ENDSTOP_INTERRUPTS_FEATURE

#define SDSUPPORT

These are the board specific Configuration_adv.h changes:

#define MINIMUM_STEPPER_DIR_DELAY 20
#define MINIMUM_STEPPER_PULSE 0
#define MAXIMUM_STEPPER_RATE 400000

#if HAS_TRINAMIC

  // You can change ever value EXCEPT R_SENSE based on your setup.
  // Example values of my HEVO setup

  #define R_SENSE           0.12  // DO NOT CHANGE! Need to be 0.12 for RemRam V1
  #define HOLD_MULTIPLIER    0.3  // Scales down the holding current from run current
  #define INTERPOLATE       true  // Interpolate X/Y/Z_MICROSTEPS to 256

  #define X_CURRENT          750  // rms current in mA. Multiply by 1.41 for peak current.
  #define X_MICROSTEPS       256  // 0..256

  #define Y_CURRENT          750
  #define Y_MICROSTEPS       256

  #define Z_CURRENT          750
  #define Z_MICROSTEPS       256

  #define E0_CURRENT         400
  #define E0_MICROSTEPS      256


  #define STEALTHCHOP
  #define MONITOR_DRIVER_STATUS

  #if ENABLED(MONITOR_DRIVER_STATUS)
    #define CURRENT_STEP_DOWN     50  // [mA]
    #define REPORT_CURRENT_CHANGE
    #define STOP_ON_ERROR
  #endif

  #define SENSORLESS_HOMING // If you want to use sensorless homing

  #if ENABLED(SENSORLESS_HOMING) || ENABLED(SENSORLESS_PROBING)
    #define X_STALL_SENSITIVITY  2
    #define Y_STALL_SENSITIVITY  2
    #define Z_STALL_SENSITIVITY  2
  #endif

  #define TMC_DEBUG // Helpfull when setting up your system

#endif

src/pins/pins_REMRAM_V1.h

// Use only one or the other
#define SDSS               57   // Onboard SD card reader
//#define SDSS              9   // LCD SD card reader

Of course you need to aditionally change the configuration files based on your particular printer setup.

Virtual COM Port Support (Serial over USB)

Virtual COM Port (also known as VCOM or CDC) support will land in the "official" STM32 arduino core with version 1.5.0. If you want to use VCOM feature earlier, you can use the the "remram-cdc" branch.

Have a look at the "Update the STM32 Core using the git repository" on how to update the STM32 arduino core with a custom git branch.

The CDC support in that branch is not battle proven. So you should expect errors until the CDC support lands in the next stable release of the STM32 arduino core.