On Thu, Apr 20, 2017 at 11:30 AM, <[email protected]> wrote: > Hi all, > > I'm trying to use the eQEP Linux driver. I can get it to load by adding a > device tree overlay, but it doesn't increment much. I can see that its > loaded (called tieqep) with lsmod etc. > > I've never used a quadrature encoder before, so I question if I just havn't > connected it correctly. > > At times it doesn't increment (reading Position file in > /sys/device/ocp/epwmss48...... folder), other times it increments or > decrements 2 or 3 positions. > > If I jiggle the wheel back and forth a small a amount, it counts a lot. The > dual hall effect sensor outputs clean and clear waveforms at 3.3v, 90 > degrees out of phase, switches phase when change wheel direction just as I > expected. > > I'm only using channels A and B, did not touch other connections. > > I've tried using all 3 eQEPs separately (including the 2b overlay for > alternate pins of eQEP2). I've used Derek Molloy's P9 and P8 header files. > > Currently have proto-cape with pins 35 (A input)and 33 (B input)on P8 header > for eQEP1. > > Other eQEPs have same behaviour. I've also swapped the beaglebone black > board with a new one. > > I'm using kernel 4.4.9-ti-rt-r25 but with old llibraries and system from > like 2015 I think as Simulink doesn't officially support anything higher. I > only upgraded the kernel. > > Please let me know if anyone has any advice. > > Thanks, > Fisher
I've been using a rotary encoder successfully with the tieqep driver: https://blog.oshpark.com/2017/04/05/rotary-encoder-breakout-with-pull-up-resistors/ I'm running 4.4.47-ti-r87 on Debian 8.7. I've got it connected to P8.11 and P8.12. I'm using config-pin to set the mode on those pins. Details here: https://github.com/adafruit/adafruit-beaglebone-io-python/blob/eqep/doc/rotary-encoder-eqep-test.md The position does accurately reflect how many increments I turn the encoder knob. However, this is at a relatively low rate of speed as I can not turn the knob as fast a motor with an encoder. You could try using the Strawson library as an alternative to the kernel driver. I believe it has support for the encoders: http://www.strawsondesign.com/#!manual-encoders regards, drew -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAEf4M_Bg2WY-6VpyL-91V0C61J7zZe3k8RHL-zqVdyxzwACJEg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
