RAMPS -PWM/TTL pins?

[FlailAway]

Hi, I must be dense as I have spent most of today searching for pin assignment.

I want to use a Mega+RAMPS-1.4 or one of these, shield as I have them. I have a laser that takes a 5KHz PWM/TTL signal to drive intensity from 1% to 98% duty cycle.

I cannot find instructions on which pin to use on the Mega (or that shield) as the PWM/TTL output to drive the laser. Is there a "pins.h" I am not seeing?

Could someone please help here as I'd like to use grbl+Mega and LaserWeb.

[FlailAway]

Anyone here? The grbl wiki shows "1KHz" as "common" and says to change the cpu_map.h. That file shows 1.9KHz which is closer to 2KHz but no idea how or what to set for 5KHz.

[thawkins]

Im also looking for this information, i need to know which pins the spindle pwm, and spindle direction data is output from.

A diagram of where each function is located would be cool.

[thawkins]

This is an example of a wiring diagram for the grbl-Mega-5X project which is another AtMega/Ramps grbl project, but with 5 Axis support, this level of information is very useful for grtting it up and running. If we could have a simular diagram for the grbl-mega project (it may be very simular)

https://github.com/fra589/grbl-Mega-5X/blob/edge/doc/images/grbl-Mega-5X_Wiring.svg

[bdurbrow]

It's defined in cpu_map.h. Also helpful for figuring out the pinout is the RAMPS connector mapping: https://reprap.org/mediawiki/images/c/ca/Arduinomega1-4connectors.png

The relevant section of cpu_map.h:

  // Define spindle enable and spindle direction output pins.
  #define SPINDLE_ENABLE_DDR      DDRG
  #define SPINDLE_ENABLE_PORT     PORTG
  #define SPINDLE_ENABLE_BIT      5 // MEGA2560 Digital Pin 4 - Ramps 1.4 Servo 4 Signal pin
  #define SPINDLE_DIRECTION_DDR   DDRE
  #define SPINDLE_DIRECTION_PORT  PORTE
  #define SPINDLE_DIRECTION_BIT   3 // MEGA2560 Digital Pin 5 - Ramps 1.4 Servo 3 Signal pin

slightly further down:

  // Define spindle output pins.
  #define SPINDLE_PWM_DDR   DDRH
  #define SPINDLE_PWM_PORT  PORTH
  #define SPINDLE_PWM_BIT   5 // MEGA2560 Digital Pin 8 

[sanalejo171]

Hello, I've been 2 days, testing 1 by 1 ALL the ramp pines, I can turn on and off the SPINDLER (DRILL) but none has pwm control, because they only mark 0 or 5v ........ IT ALSO WORKS ME PROBE or analog 15 or none, and probe one by one ....... someone found the solution? Or will I have to go back to Arduino one?

[fra589]

Hi, The default spindle PWM pin defined in cpu_map.h for RAMP board is the D8 pin defined with this :
(only D8 can output PWM more than 5v on RAMP board)

  // Define spindle output pins.
  #define SPINDLE_PWM_DDR   DDRH
  #define SPINDLE_PWM_PORT  PORTH
  #define SPINDLE_PWM_BIT   5 // MEGA2560 Digital Pin 8

Then, the PWM output range is defined by this (still in cpu_map.h) :

  // Advanced Configuration Below You should not need to touch these variables
  // Set Timer up to use TIMER4B which is attached to Digital Pin 8 - Ramps 1.4 12v output with heat sink
  #define SPINDLE_PWM_MAX_VALUE     1024.0 // Translates to about 1.9 kHz PWM frequency at 1/8 prescaler
  #ifndef SPINDLE_PWM_MIN_VALUE
    #define SPINDLE_PWM_MIN_VALUE   1   // Must be greater than zero.
  #endif
  #define SPINDLE_PWM_OFF_VALUE     0
  #define SPINDLE_PWM_RANGE         (SPINDLE_PWM_MAX_VALUE-SPINDLE_PWM_MIN_VALUE)

Then, you need to define MIN and MAX speed in the DEFAULTS_RAMPS_BOARD section of default.h file :

#ifdef DEFAULTS_RAMPS_BOARD
  #define DEFAULT_SPINDLE_RPM_MAX 1000.0 // rpm
  #define DEFAULT_SPINDLE_RPM_MIN 0.0 // rpm

(those default values can be adjusted after flashing by the $30 and $30 Grbl parameters).

If your RAMP is 12v powered, the SPINDLE_PWM_MAX_VALUE is 1024 and the SPINDLE_RPM_MAX is 1000, then the max output of PWM will be 12v when using :
M3 S1000 It will be about 6v using :
M3 S500

You can adjust max power lower than the RAMP input voltage by adjusting the SPINDLE_PWM_MAX_VALUE lower than 1024.

I hope this help you,

@++;

Gauthier.

[sanalejo171]

Hola, el pin PWM de husillo predeterminado definido en cpu_map.h para la placa RAMP es el pin D8 definido con esto: (solo D8 puede emitir PWM más de 5v en la placa RAMP)

  // Define spindle output pins.
  #define SPINDLE_PWM_DDR   DDRH
  #define SPINDLE_PWM_PORT  PORTH
  #define SPINDLE_PWM_BIT   5 // MEGA2560 Digital Pin 8

Entonces, el rango de salida PWM se define por esto (todavía en cpu_map.h):

  // Advanced Configuration Below You should not need to touch these variables
  // Set Timer up to use TIMER4B which is attached to Digital Pin 8 - Ramps 1.4 12v output with heat sink
  #define SPINDLE_PWM_MAX_VALUE     1024.0 // Translates to about 1.9 kHz PWM frequency at 1/8 prescaler
  #ifndef SPINDLE_PWM_MIN_VALUE
    #define SPINDLE_PWM_MIN_VALUE   1   // Must be greater than zero.
  #endif
  #define SPINDLE_PWM_OFF_VALUE     0
  #define SPINDLE_PWM_RANGE         (SPINDLE_PWM_MAX_VALUE-SPINDLE_PWM_MIN_VALUE)

Luego, debe definir la velocidad MIN y MAX en la sección DEFAULTS_RAMPS_BOARD del archivo default.h:

#ifdef DEFAULTS_RAMPS_BOARD
  #define DEFAULT_SPINDLE_RPM_MAX 1000.0 // rpm
  #define DEFAULT_SPINDLE_RPM_MIN 0.0 // rpm

(esos valores predeterminados se pueden ajustar después de parpadear con los parámetros Grbl de $ 30 y $ 30).

Si su RAMP está alimentada por 12v, el SPINDLE_PWM_MAX_VALUE es 1024 y el SPINDLE_RPM_MAX es 1000, entonces la salida máxima de PWM será de 12v cuando se use: M3 S1000 será de aproximadamente 6v usando: M3 S500

Puede ajustar la potencia máxima más baja que el voltaje de entrada RAMP ajustando el SPINDLE_PWM_MAX_VALUE más bajo que 1024.

Espero que esto te ayude,

@ ++;

Gauthier

Hi, first thanks for implementing this necessary firmware for ramps and for responding so quickly:

1. The probe did not work in any way, with version 1.1f of your program, I finally found this site where you host the latest versions https://github.com/fra589/grbl-Mega-5X/releases
2. The pwm worked on d8, it was necessary to connect a source of 12 I just made a bridge of the main and perfect source, I am using a mosfet irf 540n, to control a 42v spindle connect + to the gate - to the voltage in and the third leg to the spindle negative and the spindle positive direct to the source everything finally works, I no longer need a shield v3
3. I would like to learn how to edit the code, because in this expression: #define SPINDLE_PWM_BIT 5 // MEGA2560 Digital Pin 8 ................... says bit 5 but it works with pin 8, where I know which bit corresponds to which pin ???? thank you

[fra589]

Hi, The v1.1f release on my fra589's grbl-Mega-5X github is not fully up to date, I wrote some bugs corrections and new enhancements since 2018 july. I published the hex file coresponding to the latest source release 1.1l.20190605 today.

To modify the cpu_map.h file, you need to know how the port mappingof the microcontroler. if you see the Arduino's doc here : https://www.arduino.cc/en/Hacking/PinMapping2560, you can see that the D8 pin is connected on the microcontroler port H at bit 5. so, you need to define :

  #define SPINDLE_PWM_DDR   DDRH
  #define SPINDLE_PWM_PORT  PORTH

for the port, and :

  #define SPINDLE_PWM_BIT   5

for the bit number on the I/O port.

For more precise niformations on how to programming the microcontroler, you can see ATmega2560 datasheet here :
https://www.microchip.com/wwwproducts/en/ATmega2560

@++;
Gauthier.

[ksdfpr]

Hi, The v1.1f release on my fra589's grbl-Mega-5X github is not fully up to date, I wrote some bugs corrections and new enhancements since 2018 july. I published the hex file coresponding to the latest source release 1.1l.20190605 today.

To modify the cpu_map.h file, you need to know how the port mappingof the microcontroler. if you see the Arduino's doc here : https://www.arduino.cc/en/Hacking/PinMapping2560, you can see that the D8 pin is connected on the microcontroler port H at bit 5. so, you need to define :

  #define SPINDLE_PWM_DDR   DDRH
  #define SPINDLE_PWM_PORT  PORTH

for the port, and :

  #define SPINDLE_PWM_BIT   5

for the bit number on the I/O port.

For more precise niformations on how to programming the microcontroler, you can see ATmega2560 datasheet here : https://www.microchip.com/wwwproducts/en/ATmega2560

@++; Gauthier.

Could you help me with this board? (GT2560) What have I to change to work with PWM3 (physical pin 1) bed pin? Here is the board https://www.geeetech.com/forum/viewtopic.php?t=19092&start=10#p84673 I have made some tests but without pwm success, only on/off. Laser ttl freq 0-20KHz

[jransp]

Ok , PWM TO TTL It's very easy just get a PNP transistor and 2 resistors. PWM signal is the spindle negative signal wire