rotary encoder resolution

Projects General Guidance
1

Hi folks,

please advice someone to help me select correct rotary encoder, more likely its number of steps per revolution.

Wanna build tracked robot, each drive own actuator, shaft (with encoder) max. 120RPM
I would like to use Arduino Due due to clock freq. and number of interrupts.

And here is coming my unclear point, cosidering that each encoder will use two interrupts, 2 * 2 = 4

Encoder like this one:

576×576 64.3 KB

Can be selected with resolution from 100~600 pulses per revolution.

Considering 120RPM so 2 revolutions per sec. so:
2 (revolution) * 100 (pulses) * 4 (interrupt pins) = 800 interrupts per second:)
2 (revolution) * 600 (pulses) * 4 (interrupt pins) = 4800 interrupts per second:)

If you still follow my flow, question is simple, will be 70Mhz clock speed able to handle 4800 interrupts per second reliably? Or should I rather go with 100 puls resolution?
Does it gonna work at all?:smiley:

Any feedback appreciated! Cheers Mira

2

the Arduino Due uses a AT91SAM3X8E which has two hardware QEI interfaces

see 36.6.14 of
http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-11057-32-bit-Cortex-M3-Microcontroller-SAM3X-SAM3A_Datasheet.pdf

3

Thanks for reply!

Wow, there is hardware solution in that little chip? awesome!
So I suppose I should use those specificy pins :smiley:

I would never found that my-self! Thank you!

Only question is, are those features supported by Arduino IDE?
Ofcourse it does...
continue here if you like!
https://forum.arduino.cc/index.php?topic=140205.75

Thank you horace! Have a nice day!