Onsemi LV8729V microstep sine wave output current waveform captured with a oscilloscope using a current probe.
LV8729V is a 32volt, 1.8amp, up to 128 microstep driver. Individual drivers can be purchased on eBay for about $3.75. This one was manufactured by Lerdge. The driver output current waveform looks much nicer than the DRV8825 and A4988 drivers. It drives the stepper motor smoothly at both 12 and 24volts.
Measured output current
LV8729V 8 microstep 5rpm 12volts. Output current set to 0.5amps rms.
LV8729V 8 microstep 5rpm 24volts. Output current set to 0.5amps rms.
LV8729V 8 microstep 100rpm 12volts, Output current set to 0.5amps rms.
LV8729V 8 microstep 100rpm 24volts. Output current set to 0.5amps rms.