100k resistor on MS1 pin of A4988 Carrier April 29, 2014 08:13AM |
Registered: 10 years ago Posts: 166 |
Re: 100k resistor on MS1 pin of A4988 Carrier April 29, 2014 04:25PM |
Registered: 10 years ago Posts: 869 |
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Microstep Select (MSx). The microstep resolution is set by
the voltage on logic inputs MSx, as shown in table 1. The MS1 and
MS3 pins have a 100 kΩ pull-down resistance, and the MS2 pin
has a 50 kΩ pull-down resistance.
Re: 100k resistor on MS1 pin of A4988 Carrier April 30, 2014 01:27AM |
Registered: 10 years ago Posts: 166 |
Re: 100k resistor on MS1 pin of A4988 Carrier April 30, 2014 08:22AM |
Registered: 13 years ago Posts: 7,616 |
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FBITuco
I'm wondering why every circuit diagram (Of repRap electronics) has 100k resistor to ground on MS1 pin.
Generation 7 Electronics | Teacup Firmware | RepRap DIY |
Re: 100k resistor on MS1 pin of A4988 Carrier April 30, 2014 09:38AM |
Registered: 10 years ago Posts: 166 |
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Traumflug
Early Pololu stepper drivers (A4983 based) didn't have such a pulldown onboard, so the big electronics board had to provide one. A4983 based ones are still in use and the pulldown doesn't conflict with newer ones, so it's still kept.
Gen7 electronics took a slightly different approach, fixing MS1 to high and saving a few parts at the loss of quarter and full step microstepping modes.