Machine: Custom Build Machine
Firmware: GRBL-LPC (Self-Compiled, based on https://github.com/cprezzi/grbl-LPC )
Stepper Drivers: 4x (X,Y,Z,A) Stepper-Online DM556T (Official Leadshine Clone/Light-Version)
My Cohesion3D(Mini) Board is connected to +24V and USB(RaspberryPi)
My Stepper drivers expect binary-0 to be 0-0,5V and binary-1 to be 4.5-5V ( http://www.leadshine.com.ua/pdf/dm566.pdf page 3)
I have some trouble connecting my external stepper drivers, while setting up the “enable” pin for my first driver:
I have connected (EN+) to the +5 V Pin at my Cohesion3D(Mini) Board and the “X-enable-signal” of the Cohesion3D with (EN-) based on the directions on the homepage
A high Pegel on the output of the C3D measures 3.3V Resulting in a 1.7V “low-signal” at the stepper driver. 5V-3.3 = 1.7 --> “1.7V > 0.5V” ==> above the expected 0.5V upper limit of “binary-zero” for the stepper driver
A low Pegel on the output of the C3D measures 0.0V Resulting in a 5.0V “high-signal” at the stepper driver. 5V-0V = 5V --> “5V > 4.5V” ==> acceptable.
Based on these measurements, the observation “Motor not moving” can be explained by the invalid pegels based on the stepper drivers expectations.
- Are there true schematics for the C3D Mini (not just external connection diagrams)?
- If there are no schematics, would someone please confirm that the stepper outputs do not have level shifting and are direct 3.3V I/O pins
- what is the current limit for these I/O pins ( it seems i need to design a level-shifter/optocouplers circuit to get my drivers working if my assumptions are correct )
Btw. unrelated to the previous question: Do I need +24V external power connected if I am only using external drivers?