topic Capture Qei position and send to usb in LPC Microcontrollers https://community.nxp.com/t5/LPC-Microcontrollers/Capture-Qei-position-and-send-to-usb/m-p/519705#M3303 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by AmirHejazi on Thu Jan 31 14:24:37 MST 2013</STRONG><BR /><SPAN>Hi</SPAN><BR /><SPAN>I want to draw graphs of position of 2-phased QEI versus time, using LPC1768. it is important to draw transient state between ON &amp; OFF (to find step response!). An ENCLK_Int interrupt occurs at the every transition of the encoder and the firmware sends the timer value to USB.</SPAN><BR /><SPAN>I have written some codes. but FILE_Open, FILE_Write and FILE_Close are too slow to run in the QEI ISR, so i have send the data to a buffer and send them in batch.</SPAN><BR /><SPAN>but i don't know how to do it! :-|</SPAN><BR /><SPAN>how can i buffer the data? should i use an auxiliary register?</SPAN><BR /><SPAN>how can i detect that number of bytes written in QEITIME(or auxilary Buffer) is 512?</SPAN><BR /><SPAN>should i pend the interrupt to send the data(buffer) to USB? (cause the usb functions are too slow)</SPAN><BR /><BR /><BR /><BR /><SPAN>Best Regards&nbsp; </SPAN><BR /><SPAN>Amir</SPAN></BODY></HTML> Wed, 15 Jun 2016 17:40:14 GMT lpcware 2016-06-15T17:40:14Z Capture Qei position and send to usb https://community.nxp.com/t5/LPC-Microcontrollers/Capture-Qei-position-and-send-to-usb/m-p/519705#M3303 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by AmirHejazi on Thu Jan 31 14:24:37 MST 2013</STRONG><BR /><SPAN>Hi</SPAN><BR /><SPAN>I want to draw graphs of position of 2-phased QEI versus time, using LPC1768. it is important to draw transient state between ON &amp; OFF (to find step response!). An ENCLK_Int interrupt occurs at the every transition of the encoder and the firmware sends the timer value to USB.</SPAN><BR /><SPAN>I have written some codes. but FILE_Open, FILE_Write and FILE_Close are too slow to run in the QEI ISR, so i have send the data to a buffer and send them in batch.</SPAN><BR /><SPAN>but i don't know how to do it! :-|</SPAN><BR /><SPAN>how can i buffer the data? should i use an auxiliary register?</SPAN><BR /><SPAN>how can i detect that number of bytes written in QEITIME(or auxilary Buffer) is 512?</SPAN><BR /><SPAN>should i pend the interrupt to send the data(buffer) to USB? (cause the usb functions are too slow)</SPAN><BR /><BR /><BR /><BR /><SPAN>Best Regards&nbsp; </SPAN><BR /><SPAN>Amir</SPAN></BODY></HTML> Wed, 15 Jun 2016 17:40:14 GMT https://community.nxp.com/t5/LPC-Microcontrollers/Capture-Qei-position-and-send-to-usb/m-p/519705#M3303 lpcware 2016-06-15T17:40:14Z