Qwiic motor driver idle current draw

Robotics
1

I’m trying out the Qwiic motor driver I just bought. It controls my motors OK,

but I’m concern that it seems to draw a lot of current from the motor

power port even when motors are inactive?

After the SCMD_DRIVER_ENABLE command, the board seems to draw roughly 250mA.

That’s with my two motors stopped (SCMD_MA_DRIVE level 0).

I’m unclear what’s going on with that power, other than generating heat.

Is this expected?

Otherwise, both my motors appeared to work as expected (both directions,

different levels/speed).

If this idle draw is normal, I can work with it, just I’m worried it might not be?

After a disable command (SCMD_DRIVER_ENABLE 0) the current draw drops to about 1mA.

But some current draw seems to persist even after I powered down the Qwiic logic section.

Can I leave batteries connected on the motor power port while off, or will it drain them?

Thanks for any hints

2

250mA seems a bit excessive to me too.

If you disconnect the motors, does the current drop to next to nothing?

3

With motors disconnected, it draws about 4mA (after the ENABLE command).

So yeah.

Ah with just one motor connected instead of two (still idle), it draws around roughly half what it did yesterday: about 120mA.

There’s 0.09V on the motor terminals.

My power supply is at 8.8V.

Ah and if I increase the voltage on the power supply to 10V, voltage on the motor terminals goes to 0.102V.

Is the duty cycle perhaps actually not quite 0?

I have issued no DRIVE command since powering on.

If I do a DRIVE with some non-zero value then 0, it comes back to this same state with the current draw.

4

That’s odd, nobody has reported this before.

There could be something wrong with your board.

If you purchased the board directly off our website, just [fill in the form on this page with your order number and the URL to this forum post and we can replace it for you.

If you purchased from a distributor or Amazon you will need to let them know you have a defective product and arrange with them for an exchange.](Return Policy - SparkFun Electronics)