https://github.com/dzid26/StepperServoCAN
Limits:
- 3.3A peak stall current per phase for 5sec
- 3.3A RMS combined motor continuous current for >1min (i.e. rotating under load but not stalled)
- 32V supply voltage
Features:
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Intended to drive a stepper motor
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High impedance freewheeling with overvoltage protection
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Magnetic angle sensor (can be turned off during sleep)
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CANbus transceiver with standby mode
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Debug port for flashing and configuration with ESD protection
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Low-side current, V_mot and V_Bat, PCB temperature measurments
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Reverse polarity protection and swapped connectors protection; ESD protections on inputs
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Optional Enable port with Break interrupt capability for additional safety
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Optional expansion port for connecting UART/I2C/PWM device or a sensor
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Optional solder jumper pads, e.g. for motor identification
- single sided PCB for direct mounting on the motor and efficient assembly
- flat bottom allows for heat dissipation and measuring motor temperature
Motor tips:
- an examples of motor that produce a lot of torque without needing much gear ratio are Nema23 104mm and 56mm - they have dense windings and high torque per amp values
- for space limited applications this coupled with single stage 5:1 gearbox can provide enough torque with relatively low friction and noise from the gearbox. Note: above 2Amps, the torque tapers off and torque ripple becomes apparent!
- rated current should not be exceeded by a lot to avoid torque ripple, motor inefficiency and overheating
- motors with high rated-current (less but thicker winding) can be used to avoid torque ripple problem, provided they are geared enough to generate enough output torque - however large gear ratios can be more prone to backlash and low efficiency which adds to backdrivinility friction
- generally big motors will have smoothest torque and don't need that much gearing