makerbase-mks / MKS-DLC32

MKS DLC32 motherboard kit, which is an offline engraving master control kit developed for desktop engraving machines. The hardware is equipped with a 32-bit high-speed ESP32 module, integrated WIFI function, and directly drives a 3.5-inch touch color screen; it can realize fast engraving and WEB web pages. Control, mobile phone APP control and other functions.
https://www.aliexpress.com/item/1005003183498253.html?spm=a2g0o.store_pc_home.productList_8356958.pic_0
281 stars 112 forks source link

Insufficient current for external stepper driver enable lines #411

Open pionex opened 1 year ago

pionex commented 1 year ago

This board uses a single pin for the enable on all 3 axes. The 74HC595 outputs around 6-8mA per pin and does not have sufficient drive current to fully turn on 3 optoisolators found in a typical external stepper driver. It likely needs either a buffer chip to have sufficient drive current or otherwise needs an additional shift register in order to provide independent enable outputs for each axis.