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Laser 5.5watt Connecting issue

Posted by sauntson 
Laser 5.5watt Connecting issue
December 14, 2018 12:43PM
I recently purchased one of these

[www.ebay.co.uk]

I adjusted the Marlin on my MKS Gen Ramps1.4 board to use pin 44 for the TTL+5v Trigger and AUX GND for the -5v

Before attaching the laser, I used a multimeter to test my adjustments
When M106 S255 and multimeter, I get an expected (4.97v) S127 (2.48v)
using M106 S0 or M107 I get 0v

Now the bit thats confused me,

After connecting the Laser driverboard to a 12v supply and attaching the TTL + and - wires. I get a very faint light when sending commands
M106 S50 or M106 S255 or anything else.

If i disconnect the TTL wires I get a full power laser instantly

any ideas???????

Edited 2 time(s). Last edit at 12/14/2018 01:42PM by sauntson.
Re: Laser 5.5watt Connecting issue
December 14, 2018 05:34PM
The TTL trigger is not a voltage dependent control.
The trigger pins normally are pulse width modulated (PWM) to control laser output
More time ON ( at 5V) the greater the laser ON - more power.

So you have to set up your control pin to PWM
or select a pin that can set PWM frequency

Read
[reprap.org]

confused smiley
Re: Laser 5.5watt Connecting issue
December 14, 2018 05:46PM
Quote
cozmicray
The TTL trigger is not a voltage dependent control.
The trigger pins normally are pulse width modulated (PWM) to control laser output
More time ON ( at 5V) the greater the laser ON - more power.

So you have to set up your control pin to PWM
or select a pin that can set PWM frequency

Read
[reprap.org]

confused smiley

THANKYOU SIR

I thought I had dont this by routing D9 too D44, im new to all this and quickly getting beyond my skill set

Edited 1 time(s). Last edit at 12/14/2018 06:01PM by sauntson.
Re: Laser 5.5watt Connecting issue
December 15, 2018 08:18AM
If the multimeter shows different voltages on Pin 44 when using M106, then he is already correctly using PWM ...

Is Pin 44 a good choice? The marlin doc says that it might be already in use by the LCD?
[marlinfw.org]

And (as I also sent you via PM) you should check that your TTL GND is also connected to GND of your 12V laser power supply!

There is also a slight chance that TTL control of your board is inverted, i.e. you need M106 S0 for full power and M106 S255 for off.
Re: Laser 5.5watt Connecting issue
December 15, 2018 06:12PM
This is my issue

I remapped D9 to Pin44 to get a 5v+ for TTL.

When I had adjusted the Marlin and reflashed. Using a multimeter I got these results between Pin44 and GND

M106 S255 = 4.98v
M106 S127 = 2.54v
M106 S40 = 0.48v
M106 S0 or M107 0v

So I connected the TTL wires from my tested pin44 and Gnd to the Laser driver board and sendng any M106 codes I get a very very very dim light, even on M106 S255.

If i disconnect the TTL wires i get as expected a full power laser.

Anyone habe any serious suggestions or advice

regards
VDX
Re: Laser 5.5watt Connecting issue
December 15, 2018 07:01PM
... "Chinese TTL" can be totally different -- can you measure the drawn current and polarity of the driver?


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Laser 5.5watt Connecting issue
December 15, 2018 07:34PM
If I knew how to most probably

sorry
VDX
Re: Laser 5.5watt Connecting issue
December 15, 2018 07:50PM
... attach an external power source with +5V to see, if it will work as expected ... and a multimeter @current in series to the diode for the drawn current ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
VDX
Re: Laser 5.5watt Connecting issue
December 15, 2018 07:53PM
... "work as expected" could be with inverted polarity -- so it will burn with TTL input at GND (or open) and went OFF with +5V at the input ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Laser 5.5watt Connecting issue
December 16, 2018 05:53AM
Quote
VDX
... attach an external power source with +5V to see, if it will work as expected ... and a multimeter @current in series to the diode for the drawn current ...

Don't forget to connect both GNDs .... ;-)
Re: Laser 5.5watt Connecting issue
December 16, 2018 09:01AM
Thank you gentlemen,

This is my aim. Ill connect an independant adjustable 5v source to the TTL side and see what happens.
i have already grouped the earths together. i was reading last night about debugging using M43 but have
never done that before so that will be a massive learning curve,

I am thinking by adding an independant 5v to the TTL. It would show if i have power, so long as it works

I may just put the router back on and forget about a laser.............. reading about this upgrade, it seemed so simple.
But it really isnt

regards
Re: Laser 5.5watt Connecting issue
December 16, 2018 10:46AM
Hi

I feel progress is being made
I disconncted the TTL wires and attached them to a 1.5v battery.
My thinking be if the TTL was working then the laser should come on at a lower power.
wrong, powering the system, with the battery attavhed. resulted in no Laser, disconnect the batteryand laser somes on full power

does this suggest anything to you guys, ??? failed TTL side of laser driver???


regards

stuart
VDX
Re: Laser 5.5watt Connecting issue
December 16, 2018 11:57AM
Hi Stuart,

could be, the TTL-input is an optocoupler and the 1.5V from the battery are enough voltage to activate the diode in the coupler.

Your previous attempts with the +5V form the controller pins didn't gie enough current for the diode, so it wasn't activated.

You can measure the voltage of the TTL+ pin when connecting to the +5V of your controller -- if it drops below +1.5V, then it's not enough current and you'll need a driver ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Laser 5.5watt Connecting issue
December 16, 2018 12:09PM
I think I understand what your saying.

I should apply the 5v from the controller and measure the power going to the laser from the driver board???.

Sorry had a problem understanding your reply.

1.5v from the battery are enough voltage.

I already know that I can contolr the output voltage using M106 S0-255 and the output voltage is accordingly set from the control board.

I'll go now and check

Edited 1 time(s). Last edit at 12/16/2018 12:10PM by sauntson.
Re: Laser 5.5watt Connecting issue
December 16, 2018 05:29PM
UPDATE

I have just rechecked my settings and can conform this

using

M106 S255 the TTL wires have 4.95v
The Laser out on the driverboard is measured at 3.52v

M106 S127 the TTL wires have 2.29v
The Laser out on the driverboard is meansured at 2.84v

hope this helps
Re: Laser 5.5watt Connecting issue
December 16, 2018 07:58PM
What is maximum current output of your 12V DC power supply?
Your gonna need > 4 amp

confused smiley
Re: Laser 5.5watt Connecting issue
December 16, 2018 07:59PM
15amps
Re: Laser 5.5watt Connecting issue
December 16, 2018 08:47PM
Maybe I should try this.

To run my Laser I need to find a 5v PWN connection on my MKS 1.4 Gen Ramps Board,

I thought I had already remapped D9 to Pin44 by adjusting pins_ramps.h. When tested with my DMM I get varying readings at the pins depending on
the S setting of my M106 eg M106 S127 = 2.48v

Attaching my Laser and then powering the system, I get no laser on startup, which I understand is correct, however sending
M106 S255 from terminal does not turn the laser on full power, nor does M106 S127 give me 1/2 power...... I get literally the dullest glow.

I am at a loss........ sinking fast

regards
Re: Laser 5.5watt Connecting issue
December 16, 2018 10:14PM
SORTED

in desperation and having read many many forums and threads, One thing that kept coming through was poorly documented driver wiring. So I decided to change the TTL wires around and it suddenely began working as required and is fully adjustable. On startup I get a quick blast of the laser, but think I read somewhere of adding a 10kohms resistor across the + / - to prevent this.

next thing is. can i take these googles off yet.

regards and respect to all,........

Edited 1 time(s). Last edit at 12/16/2018 10:15PM by sauntson.
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