Example: LPC1343+ FreeRTOS + USB example

deadsherrif wrote on Friday, July 15, 2011:

Does any example of this combination of examples exist ? Seems a more usefull demo of the USB function than just the naked HID example provided…better for RTOS as well ….who wants to manage real time comms for control from scratch ?
If anyone cares to offer advice about pitfalls that may have done this before I start out I will undertake to provide it to the community the combined example - documented when complete …It’ll be the first stage of my next project ……any contributions of advice ? (I assume there isnt one already?)

rtel wrote on Friday, July 15, 2011:

I’m not sure what functionality you are wanting from the USB specifically, but I think you can find lots of bare metal examples around - look in the Examples directories of the IAR, Keil, CodeRed tools, and on the NXP web site.  It would then be an exercise in converting it to be FreeRTOS friendly (which normally means, not doing any processing in the interrupt itself, but using the interrupt to unblock a high priority task to do the processing).


deadsherrif wrote on Saturday, July 16, 2011:

Thks Richard …your suggestion is understood as mandatory ….my questions are more philosophical ….does the buffering provide any fifo operation …saving the say “Task_read”  or  “Task_write” tasks hanging around ? I would like to save as much time as possible on the time demands of the USB interface …this is a control application and feedback phase delay will be critical …. the USB is in the path of the primary (low freq) loop …ie the outer loop…
The SIE engine converting serial to parrallel…does it have any “buffer full” or somesuch …the SIE run any DMA on the memory is implicit in this question and maybe it doesnt …. I must read this stuff ….and float a rough spec with you …whaddya reckon ? You can add some requirements along thiese lines now if you like with suggestions…it must be HID/Interrupt and of course a “device” implementation…