Regardless of my age, I can read and also have a little knowledge about electronics. I know a little knowledge is a dangerous thing, but that pen style multimeter looks indentical to one I had back in the 80s. Probably why it is cheap enough to give away with a packet of cornflakes - they recouped their R&D years ago.
And yes we had stepper motors even then. The only thing which has changed (and even then only slightly) is the driver designs, as engineers try to eak out every last percentage point in extra efficiency. Yes, I hadn’t checked the spec sheet on the TI DRV8824 but the fact remains that using any sort of a meter instead of a scope to measure the current (derived for volts across the sense resistors is doomed to failure.) The specs say that that response times to current requirements are in the nS range. This is much faster than any meter will respond and produce a reliable reading.
I was trying to point out that @mykepredko 's meter reading of 0.8V is probably very much on the low side and thus current is probably higher than his calculated 1.6A.
The reason @mykepredko is finding the chip getting warm is that even if he has “measured” 1.6A, he is running the at its design limit, and he doesn’t need a meter to tell him that. A better purchase would be a fan to blow some air over that diddy heatsink.
There are many helpful methods on the web showing that one way to set the pot on the driver is to set it so that that the motor doesn’t drop steps and then add a touch more to cover unexpected load demands. Especially in the case of the project for his daughter where she just needs it to be continuously rotating. No unexpected accelerations,
From the TI spec:
Number of full bridges 2
Vs (min) (V) 8.2
Vs ABS (max) (V) 47
Full-scale current (A) 1.6
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@Sineos Yes I too stream my music and haven’t taken a CD out of its box since longer than I can remember. Although I hear that vinyl is now the thing. Maybe I need to use this magic thing called the internet to find a new rubber band for the turntable I have in the attic somewhere.