MachineKit Stepper Driver
Uses TMC2130
Uses ATSAMD51
Has AS5047 backpack ?
IC Spec'ing
Step Driver
I like the Trinamic TMC2130 and TMC262 - the 2130 has h-bridges built in and is suited to NEMA17 size motors - fairly common. The TMC262 is a very similar chip, but only has pre-driving circuitry for external bridges. This means I can use very similar layouts for two 'sizes' of driver - however, they have different register tables, which is a bit of a bummer. I would be writing twice the software (ish). The other option is to roll a board with the TMC626, using very tiny external mosfets and then later very trivially using much larger mosfets, in the rare case that I want a, say, NEMA 34 or 42. Also, I can roll one off the bat that will be solid for NEMA 23s - normally about 2.5 amps of current. This should be no problem.
OK: so - TMC262 w/ external fets, here we go.
Mosfets
I also need: Mosfets then, as I'm going for external option. 8 per board: 2 full bridges. I'll look for arrays - like two or four in a package, this should help keep things small. I like two, for each h-bridge... There is a nice 4.1A continuious / 14A peak DirectFet in a small package - this might be appropriate for a big driver. As it turns out, there's this appropriate-looking full H-bridge in a small package that will drive 8 Amps at 60v. That's enough for even fairly large steppers... It's got a reasonable RDSon and pretty tiny gate charge... so I feel OK about this as a first shot. Bueno. I am ready to get a schematic going and build library parts.