Max Encoder/Interrupt Frequency?

[kaszeta]

Originally Posted by duane

We are going to be using three encoders, two for position control (on the drive wheels) and one for speed control. We expect the motor that we need speed control on to be going a max of about 2500 RPM. We are using the 63K encoders that should handle this speed, but I'm concerned about the interrupt speed on the processor.

Are we going to overwhelm the processor? If the processor is at 10MHz, 2000RPM with a 64 PPR encoder is a little over 2100 interrupts per second. That doesn't seem to bad, but we don't have first handle knowledge like some others.

Add in some positioning encoders, and is this going to work?

Thanks for the advice.
...Duane

This should work fine. I decided to torture-test our current software setup: Camera, Gyro, and six encoders (we won't use all of them), and some reasonably intensive trig functions. Wiring up one encoder to all six encoder channels and spinning it with a high-speed drill, the code could keep up with it until just under 1600 pulses per second. Dropping this to just the first two encoders (which don't share an interrupt line), it can do at least 6000 pulses second (as fast as my drill went). So I don't think you'll have problems.