Review – ST820 Stepper Drivers

Published by Roy Berntsen on

ST 820 Review – Short

I did not find a need for the ST820 drivers on a 8 bit board. Reason for this is that we can not utilize more than 1/32 micro-stepping due to restrictions by the ATmega2560 mictochip

The drivers are acting pretty much like the DRV8825 drivers although with less noise

For low noise and high microstepping we need to use interpolation on the Atmega so we need the Trinamic drivers for this. I talk more about the different variations here

NB! These drivers need ACTIVE HIGH stepper enable pin in Marlin firmware

// For Inverting Stepper Enable Pins (Active Low) use 0, Non Inverting (Active High) use 1
// :{ 0:’Low’, 1:’High’ }
#define X_ENABLE_ON 1
#define Y_ENABLE_ON 1
#define Z_ENABLE_ON 1
#define E_ENABLE_ON 1 // For all extruders

Key Features – The originals:

  • Operating voltage from 7 to 45 V
  • Maximum output current 1.5 Arms
  • RDSon HS + LS = 1 Ω typ.
  • Microstepping up to 1/256th of step
  • Current control with programmable OFF time
  • Current sensing based on external shunt resistor
  • Full protection set
  • Non-dissipative overcurrent protection
  • Short-circuit protection
  • Undervoltage lockout
  • Thermal shutdown
  • Standby low consumption



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