Convert GRBL signals step to analog. OPAMP simple DAC doesnt work Started BEE

I believe i need a translator arduino to interface between the components. I know im in over my head but i need to do something to get my project at least moving. Im building a router, printer, laser engraver all the components and structure is done i just can get the damn electronics talking.

I have nothing but BLDC motors which i thought was great since they will be more accurate etc. The challenge is getting them to talk. I found in github a SME that designed a dc closed loop control for arduino mini to interface with a AB encoder 400 lines and then convert the step signals to PID for the driver.

My problem
Ive tried DAC even adding OPAMP but the signal from the steps is still not visible. I got the oscilloscope and the duty cycle is only 2% always the only thing that changes is the pulse width to accommodate what seems like acceleration. Total lost right now and i cannot find any low priced drivers that accept PWM. Frustrating since im going to school and my budget is sunken wreck.

What makes it worse is i dont know much about programming arduino. Tuning on leds and stuff like that doesnt help translate commutation, ttl, or anything else. Id like to have something so i can start manufacturing circuits to practice what im reading and learning.

Think about going to GearBest, or BangGood, or some place like that.
Check out their ‘3D printers and parts’ sections.
Look for a 3D printer control board that uses Arduino NANO and Stepper drivers, like what the Eleks Maker A5 Laser Engravers use.

See if that gives you any ideas.

The thing is i have to use bldc since the structure has the bldc integrated into the ball screws.

OK, at least you've started out with the right attitude. We're all here to learn too.

I can't tell from your original post if you are having trouble with the input from the encoders or the output to the BLDC's.

Can you tell us what is working? Can you tell us what you expected it to do? Can you tell us what it does now, which you want to change.

Low-priced BLDC drivers are likely to be based on radio-control hobbies. They usually act like a servo, which is more like PPM than PWM. Try the Arduino Servo library.