MKS SGEN_L is a powerful 32-bit 3D printer control board with LPC1768. Support Marlin2.0, Smoothieware. Support MKS LCD12864B/MINI12864/LCD2004/12864 and MKS TFT Touch Screens. The motherboard integrates SPI / UART interface and works with MKS TMC2130/TMC2208 V2.0/TMC2209. It can be used after plugged in. No soldering or flying lead is required ...
MKS_SGEN_L board schematic shows, for limit switches (X-, X+, Y-, Y+, Z-, Z+), that they include onboard 10K ohm pullup resistors to VCC (3.3V), decoupling capacitors from signal to ground, and 1K ohm limiting resistors between Signal and Processor pin. The LPC1768 has internal pullup feature which can be enabled. Why were these pullups added to the board?
Since pullups are included on the board, why does the sample Marlin 2.0 Configuration.h file enable the processor pullups feature for those limit switch functions?
The MKS_SGEN_L Datasheet also provides Marlin 2.0 code sample showing them enabled by firmware.
MKS_SGEN_L board schematic shows, for limit switches (X-, X+, Y-, Y+, Z-, Z+), that they include onboard 10K ohm pullup resistors to VCC (3.3V), decoupling capacitors from signal to ground, and 1K ohm limiting resistors between Signal and Processor pin. The LPC1768 has internal pullup feature which can be enabled. Why were these pullups added to the board?
Since pullups are included on the board, why does the sample Marlin 2.0 Configuration.h file enable the processor pullups feature for those limit switch functions?
The MKS_SGEN_L Datasheet also provides Marlin 2.0 code sample showing them enabled by firmware.