Try this method for tuning the driver, if any step is not as described, do not connect the laser. It is very delicate and can burn instantly:
Maybe make it easier to adjust in this way:
You will need an LED diode to be used instead the laser diode for checking the correct driver operation.
-Adjusts the voltage to 6.5V (with small metal potentiometer).
-Turn the potentiometer counterclockwise current (multi-turn type blue) down to minimum set, you will hear "click, click" when done (may need up to 30 turns, because it is multi-turn type).
-Connect The LED to driver output inserting the ammeter (do not forget the pulldown resistor and note the polarity).
-Using 3dpBurner Sender app set the power laser to 10, (put 10 in the text field and click the PWR button, or send the "S10" command manually), the LED will remain off even and should answer "S10
- Turn LED on (press "Laser ON" or send the M3 command), the LED should light, Ieave it on for about 1min it not sould burns, then turn it off (button "laser OFF" or M5 command).
-Now comes the "destructive" test, sets the laser power to 255 and put your eye on the ammeter, the LED should remain off yet. Now, when you turn on the LED again consumption should be about 200mA, which is the minimum set for the driver, in these circumstances the LED will burn after some seconds, you can turn on and off several times for very short time periods (1s) checking the current (should be 150-250mA). If all goes well now you can destroy the LED by turning on ad checking both the current (should be about 200mA) and the LED endurance (only a few seconds).
-If all is ok, the driver sems to be ok. Now set the power back to 10, press "laser OFF" and remove the power supply (USB and power), remove the LED, short driver output for discharging the capacitor and connect the laser with the ampmeter (note polarity).
-WEAR YOUR SAFETY GLASSES and connect the power angain. Set laser power again to 10 and turn ON checking the ammeter, it should go below 200mA, if more or laser does not light immediately turn OFF something goes wrong (it is possible that such a low power laser can not see with the glasses on, carefully looking over to see if it really is turned on or not).
-Set the power up in steps of 10 or 20 up to 255, as it rises the current should go up to about 200mA.
-Once at 255, increase the current very slowly with the blue potentiometer until you reach the desired current(1.65A in my case for laser use).
-Set different laser powers (0-255) to check that everything is OK.
-All is ok now. You can disconnect the ammeter and test again.
-If after some minutes at full power on (255) the laser heatsink burn to the touch, use a little lower current setting (or do not use max power for long periods).
