The DRV8825 is a stepper motor driver board that has on a DRV8825_chip that enables control of stepper motors through arduino type programming firmware and software.
The DRV8825 board can supply up to 2.5-A peak or 1.75-A RMS output current (with proper heatsinking at 24 V and 25°C).
A simple step/direction interface allows easy interfacing to controller circuits. Pins allow configuration of the motor in full-step up to 1/32-step modes. Decay mode is programmable. Internal shutdown functions are provided for overcurrent protection, short circuit protection, undervoltage lockout and overtemperature.
It is one of the two most popular add-on stepper motor driver boards, along with the 4988. The increased 1/32 step mode more than makes up for the slight increase in cost compared with the A4988.
- PWM Microstepping Motor Driver
- Built-In Microstepping Indexer
- Five-Bit Winding Current Control Allows
- Up to 32 Current Levels, 32 step modes, meaning a 360 degree turn can be done in upto 32 steps of 11.25 degrees each.
- Low MOSFET On-Resistance
- 2.5-A Maximum Drive Current at 24 V, 25°C
- Built-In 3.3-V Reference Output
- 8.2-V to 45-V Operating Supply Voltage Range
- Thermally Enhanced Surface Mount Package
The following table compares Made in China A4988 Stepper driver boards vs DRV8825 ones, for RepRap use:
|Availability||very widely available||widely available|
|Approx. price||$6.80 / 5 pieces||$10 / 5 pieces|
|Max. theoretical current||2A||2.5A|
|PCB color||Green / Red||Purple|
|Stepper current adjust. trimpot||Yes, near Dir pin||Yes, near En pin|
|Typical Rs value|| 0.05 Ohm or
0.1 Ohm or
|Vref formula (*)||I_TripMax= Vref/(8*Rs)||I_TripMax= Vref/(5*Rs)|
|Thermal Overload Protection (**)||Yes||Yes|
|Small heatsink included (***)||Almost always||Sometimes not|
|Active cooling required?||Recommended||Recommended|
|IC packaging||5x5mm 28-lead QFN||9.7x6.4mm 28HTSSOP|
Note that some important technical characteristics from the respective datasheets of the ICs are not directly comparable. For example, the DRV8825 is fully specified in terms of thermal characteristics, the A4988 is not. Another important characteristic that unfortunately is not directly comparable is RDSon, which is specified at different current levels in the respective IC datasheets.
- Reddit thread showing that it is a problem for printing
- Avoiding missing steps at low speeds
- Reasons for noise and strategies to reduce noise