Need to settle on hardware

[jeff-voight]

• DRV8825 (TI Stepper Driver)
• ATMEGA328P
• FT230 (UART)
• DHT11 (Temp Sensor) What step size encoder? What ratio gear for the stepper? Is 27:1 the only reasonable choice? Should the encoder be fixed to the PCB or on a cable? Which cable?

Temperature sensor should not be exposed to stepper driver thermal anything.

USB cable can not power anything. Otherwise, we have to handle usb standby.

[jeff-voight]

I am able to etch a board with the DRV8825 and the FT230 footprints (I forget which footprint, but they're stupid small).

But, I worry about VIAs in the board for the home etcher. 1.3mm and .8mm drill seems about right, if not a little larger.

The board will have to be large enough to handle the spacing required for large drill holes (where .8mm is large).

The other issue I run into when etching my initial prototypes is that tiny traces fall off, so while .2mm traces are required for some of the pin pitches, that copper width needs to go up to .4mm with .3mm separation as quickly as possible.

I also want to find a trivial case that one could purchase at home depot or digikey or wherever. I don't mind if somebody wants to develop some fancy ergonomic case for the 3d printer, but the board shape needs to be capable of fitting into an off-the-shelf box with a few holes drilled in it.