Hi. This has been sort of been discussed before. The most related post is t-1630644
I want to wire closed loop Coolmuscle steppers that have their own drivers.
The driver’s specs for Stp and Dir signal are 3.0 to 24V and 7-15mA
So smoothieboard is Ok regarding voltage (3.3V) but not current, as it can only deliver 4mA, right?
Worst case I could use level shifters as Arthur says they can output 220mA in the related post.
However, I would prefer a more immediate solution if possible. Would open drain as described in the general-appendixes article work with an external supply for more than 4mA as this driver needs? Or does the 4mA limit still apply ?
First I should say my main power supply is 24V and attached here I also have a 5V, 3A supply.
I would wire it as follows:
- +Stp and + Dir from the external drive to an external +5V supply (or do I need to wire it to the limit switch 5V as in the previous article?
- -Stp and -Dir from the external drive to smoothie St and Dir pins respectively
- Ground pin from external drive I will leave disconnected as the coolmuscle will be grounded through the printer frame to the 24Vsupply (-) . Or should I connect this to smoothie GND pin (next to St and Dir pins) ?
- I don't plan on using the enable pin on smoothieboard and will just wire directly:
-
- 24V power from stepper to external +24V on supply
- Power ground from stepper to external (-) on supply
-
Also I will need to enable Open drain for all St and Dir pins like:
alpha_step_pin 2.0o
alpha_dir_pin 0.5o
Does all this seem right?
For anybody interested on doing this setup, in order to make the coolmuscle work with steps/pulse and direction, k36.1 must be set to 1 in the coolmuscle setup
Thank you all 
Imported from wikidot