topic Re: A simple quadrature encoder interface (qei) project in LPC Microcontrollers

A simple quadrature encoder interface (qei) project

lpcware — Wed, 15 Jun 2016 17:50:11 GMT

Content originally posted in LPCWare by cybersteve on Tue Sep 23 07:00:31 MST 2014
Can anyone supply me (point me to) a basic QEI project (Keil or IAR). I have found lots of references and inclusions in other projects, but not have been able to construct a simple project that can return the encoder position from the LPC1768 QEI interface. I am not looking for a high speed decode, as for BLDC motor control, just the ability to return the position of a rotary encoder.

I have found the lpc17xx_qei.c and lpc17xx_qei.h files, but could not make a project from them because of missing references.

Bit of a novice, sorry.

Thanks

Re: A simple quadrature encoder interface (qei) project

lpcware — Wed, 15 Jun 2016 17:50:11 GMT

Content originally posted in LPCWare by LabRat on Tue Sep 23 17:41:44 MST 2014
There's an old example in lpc17xx.cmsis.driver.library.zip:

http://www.support.code-red-tech.com/CodeRedWiki/NXPDriverLibraries

Re: A simple quadrature encoder interface (qei) project

lpcware — Wed, 15 Jun 2016 17:50:12 GMT

Content originally posted in LPCWare by cybersteve on Fri Oct 03 05:23:36 MST 2014
The CMSIS example is only for velocity - I have found no way of returning position.

Re: A simple quadrature encoder interface (qei) project

lpcware — Wed, 15 Jun 2016 17:50:13 GMT

Content originally posted in LPCWare by mc on Fri Oct 03 10:31:37 MST 2014
Hi cybersteve,
LPC1500 uses same encoder inteface as LPC1700. Please have a look at below code example
http://www.lpcware.com/system/files/LPC1500%20PMSM%20FOC%20Control_v1.1.zip

Re: A simple quadrature encoder interface (qei) project

lpcware — Wed, 15 Jun 2016 17:50:13 GMT

Content originally posted in LPCWare by cybersteve on Sat Oct 04 22:55:03 MST 2014
Thanks for the pointers, guys. I have made the cmsis stuff work eventually. I could get no position return because the maxposition value for the the interface was set at 0. Took some finding. 0:)