Hi.
Not sure if this is the right section to post this, please correct me if it's not.
I have a laser engraver with a 2 watt laser the uses 0 to 5 volt PWM to control the power of the laser.
I use GRBL 1.1h which sends the 0 to 5 volt PWM out to pin 11 of my Genuine Arduino UNO.
I want to upgrade the laser to a more powerful one, the one I have been looking at uses PWM at 0 to 3.3 volts instead of 5.
Is it possible to convert the signal to 3.3v before it goes to the laser.
I was looking at logic level converters but not sure if they are ok with PWM signal.
Also, would it need to be bi-directional, I'm assuming it would only have to be 1 way.
Something like 5 volt PWM signal in to a 1 k resistor connected in series with a 2 k resistor with the other end of the 2 k to gnd. The junction of the 2 resistors and gnd as the output = 3.3 volts.
Do I need to be concerned about the value's of the resistors, cos I get 3.3 volts using 1 ohm and 2 ohm or 100 and 200 or 10k and 20k, or any values where 1 is double the value of the other.
1k/2k2 is a good compromise value, reasonably fast without demanding high currents.
100/220 would overload most logic families (not an Arduino Uno pin though) and be properly fast.
100k/220k would be very slow due to stray capacitance, perhaps working for serial, but not for
fast logic signals or high PWM frequencies. It would also require the input not have any pullup or pull-down resistors
