DBH-12V Motor Driver

Has anyone tried using this driver board with a stepper? I’m curious if the current sensing will work with the library. Looks like you have to read a voltage on one of the pins to get the current…

CT Output Voltage(V)=Current(A) x 0.155

Just looking at getting some hardware to experiment with SimpleFOC and this board seems to tick all the boxes (affordable, high current, current sensing).

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Looks nice! I wish they would post schematic. Depending on the parts it could also be a nice board for BLDC, if the 4 PWM inputs are really 4 half bridges.

FYI there is no current sensing for steppers (yet). There are a handful of people working on this at the moment, though.

Ah, so even if the current sensing was compatible with SimpleFOC, it wouldn’t work with a stepper? Was looking at steppers rather than BLDC motors as you get a lot more torque/$.

No, in theory you can do it, it’s just currently not implemented yet in simpleFOC.

As long as you can read something that linearly correlates with the current it could be used. I agree about the torque, I have recently been working on stepper projects as well!

I only see In1 + IN2 on the header as input and the german translation says “Dual H bridge”
I’m sure its only suitable for one stepper or two brushed DC motors.

It looked like there was IN1 and IN2 for both A and B (on each row of header) to me, maybe not.

That’s also possible :+1:
The user would need complementary PWM with dead-time then.

But I don’t see how to use only three of them for a BLDC? IMHO there are two highside FETs and two lowside FETs. Can sFOC deal with it?

The description of this board says that the PWM fill should be no higher than 98%. Can this be customized?

I think by adjusting driver voltage limit relative to power supply, you could set a hard limit which is less than 98%.

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Yes, it really is. For stepper motor, you can use 4 pwm mode and for bldc motor, 3 pwm mode. A voltage divider is apparently needed to measure the current

I found a schematic for this driver. Apparently, the current meaning works for the channel. A shunt resistor is used on two half-bridges. That’s why I always get success: 2 when calibrating the current meaning. It is necessary to cut the track from the shunt resistor to one of the half-bridges.

Yes - if you set driver.voltage_limit = 0.98 * driver.voltage_power_supply then is it guaranteed that the duty cycle will not exceed 98%. :slight_smile:

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