Arduino + laser

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Arduino + laser

Post by alfi90 » Sun Apr 24, 2016 8:46 am

I decide, that laser would be great upgrade for my so2... So i purchased l-cheapo laser. Now i have laser and quite a alot of problems:)
first of all i dont want to burn my arduino, so i am looking for safe and explicit wiring diagram how to wire all up... Laser have 3 wires: Red wire to power supply +, Black wire to power supply -, White wire to Arduino digital pin 12.
I am a bit confused because ther is just one wire for ttl, so there is no connection on arduino ground...
I would like to control on/of laser option via gcode...

Here is my ideja of how to do wiering...

Thanks for your help!
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Re: Arduino + laser

Post by picengravertoo » Mon Apr 25, 2016 4:22 pm

I can only assume the black wire for the power supply (ground?) should be a common ground that needs to be wired to the ground on the Arduino also. You may want to contact the person you purchased the l-cheapo laser from on how it should be wired to be sure though.
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Re: Arduino + laser

Post by cvoinescu » Tue Apr 26, 2016 6:08 pm

As @picengravertoo said, the black wire is almost certainly supposed to be connected to Arduino GND too.

The problem with cheap wares like that is that the seller themselves may not know the answer (or just take a guess and give you erroneous information).

What you have may appear to work (depending on power supply grounding details), but it's dangerous and there's no guarantee that the laser will stay off when the Arduino tells it to turn off. You may find that accidentally disconnecting the USB turns the laser on, or that touching the machine frame turns it on... The Arduino GND must be connected.
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Re: Arduino + laser

Post by cozmicray » Tue Apr 26, 2016 6:19 pm

There is a whole section on Lasers

get your Mom to read it to you

Since you nicely made your circuit diagram too large to fit on my 60" monitor
I can't comment on wiring

JTech Photonics may help

You bought a cheap laser --- ask the supplier

What firmware / software will you be using

There is the laser diode and the laser driver board
There is a power supply connection to laser driver usually 12V 2A DC
then there is a trigger connection applying a TTL signal to trigger laser
better lasers, the trigger is opto-coupled -- so you are just driving an LED
others are not opto protected --so must comply with TTL specs
applying / removing voltage from the trigger to ignite laser
so you will have to use ground (i don't know if you want to use common ground)
TTL is 5V -- so 12V may release magic smoke

Find out what grbl you are using and see if it is capable of controlling a laser
if not get grbl version that can and connect the designated pin to PWM (pulse)
the trigger

Protect your eyes --- or buy a white cane
even reflected laser can harm --- it doesn't hurt -- it just blinds
best observe it thru usb cam


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