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gnea / grbl-Mega

An open source, embedded, high performance g-code-parser and CNC milling controller written in optimized C that will run on an Arduino Mega2560
https://github.com/gnea/grbl/wiki
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laser connected to digital pin 10 #47

Closed renebohne closed 6 years ago

renebohne commented 6 years ago

Hi,

first, thanks for this awesome project! I am trying to use it with the Makeblock Laserbot and their MegaPi board. I mapped all the pins, but my last problem is the laser pin. The MegaPi uses digital Pin 10 (PB4/OC2A). This means, that I need to use timer2 for PWM on this pin and this is an 8-bit timer... the current implementation uses 16bit-timers.

Can somebody help me with using PB4 for the laser? This is my current code in cpu_map.h ` // Advanced Configuration Below You should not need to touch these variables // Set Timer up to use TIMER2A which is attached to Digital Pin 10 - PB4 // warning: Timer2 is an 8-bit timer!

define SPINDLE_PWM_MAX_VALUE 255.0 // 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)

//rb MegaPi THIS HAS TO BE CHANGED TO A DIFFERENT PIN! OC2A is for D10 (PB4) //Control Digital Pin 6 which is Servo 2 signal pin on Ramps 1.4 board //#define SPINDLE_TCCRA_REGISTER TCCR4A //#define SPINDLE_TCCRB_REGISTER TCCR4B //#define SPINDLE_OCR_REGISTER OCR4C //#define SPINDLE_COMB_BIT COM4C1

define SPINDLE_TCCRA_REGISTER TCCR2A

define SPINDLE_TCCRB_REGISTER TCCR2B

define SPINDLE_OCR_REGISTER OCR2A

define SPINDLE_COMB_BIT COM2A0

// 1/8 Prescaler, Fast PWM mode

define SPINDLE_TCCRA_INIT_MASK ((1<<WGM20) | (1<<WGM21))

define SPINDLE_TCCRB_INIT_MASK ((1<<WGM22) | (1<<CS21))

define SPINDLE_OCRA_REGISTER OCR2A // Fast PWM mode requires top reset value stored here.

define SPINDLE_OCRA_TOP_VALUE 0xFF // PWM counter reset value. Should be the same as PWM_MAX_VALUE in hex.

// Define spindle output pins.

define SPINDLE_PWM_DDR DDRB

define SPINDLE_PWM_PORT PORTB

define SPINDLE_PWM_BIT 4 // MEGA2560 Digital Pin 10 - 12v output MegaPi

// Define flood and mist coolant enable output pins.

define SPINDLE_ENABLE_DDR DDRF

define SPINDLE_ENABLE_PORT PORTF

define SPINDLE_ENABLE_BIT 0 // MEGA2560 Analog Pin 0 - 12v output

define SPINDLE_DIRECTION_DDR DDRG

define SPINDLE_DIRECTION_PORT PORTG

define SPINDLE_DIRECTION_BIT 2// MEGA2560 Digital Pin 39 - MegaPi P15 5x2 pin1

// Define flood and mist coolant enable output pins.

define COOLANT_FLOOD_DDR DDRA

define COOLANT_FLOOD_PORT PORTA

define COOLANT_FLOOD_BIT 2 // MEGA2560 Digital Pin 24

define COOLANT_MIST_DDR DDRA

define COOLANT_MIST_PORT PORTA

define COOLANT_MIST_BIT 0 // MEGA2560 Digital Pin 22

`

renebohne commented 6 years ago

I fixed it. The MegaPi has a super slow mosfet, so I had to decrease the PWM frequency. If somebody is interested, you can have a look at https://github.com/renebohne/grbl-laserbot I close the issue in this repo, since this was a very special feature request.

Fusseldieb commented 4 years ago

@renebohne Since you've already did things with PORTs and stuff, can you help me real quick on how my definitions should look. I'm setting up a Laser and am absolutely clueless on how to make the pin D11 work on the Mega2560

https://github.com/fra589/grbl-Mega-5X/issues/138

renebohne commented 4 years ago

@renebohne Since you've already did things with PORTs and stuff, can you help me real quick on how my definitions should look. I'm setting up a Laser and am absolutely clueless on how to make the pin D11 work on the Mega2560

fra589#138

You can search for "//rb THIS CHANGED TO A DIFFERENT PIN! OC2A is for D10 (PB4) - using 8-bit timer Timer2" in file https://github.com/renebohne/grbl-laserbot/blob/master/Arduino/cpu_map.h And have a general look into my changes in that fork... but my recommendation is not to waste time on this and use official hardware instead.