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 On Saturday, 14 November 2015 03:41:59 UTC+10, dickelbeck wrote: > > > I would like to make known a bug we ran into with reading the eQEP > module that resulted in position values not updating after exactly 1020 > reads without closing the file pointer. > > Of course you are using a low level read function, not buffered userspace > IO like fscanf(). > That is, use read() not fscanf(). Then try using seek() back to file > begin, offset 0, in between reads. > > HTH, > > Dick > > > -- 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/fc07fe81-85fd-492d-9921-eafc88f89672%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
