Subject:
|
Re: Interesting BrickOS Timing Results
|
Newsgroups:
|
lugnet.robotics.rcx.legos
|
Date:
|
Wed, 15 Jan 2003 15:20:46 GMT
|
Viewed:
|
3026 times
|
| |
|
|
In lugnet.robotics.rcx.legos, Mark Riley writes:
> Looking at the code in sys_time.c, it seems possible
> that the OCRB interrupt could be consolidated with the
> OCRA interrupt, freeing the OCRB interrupt to be
> used for sample rates > 1 KHz.
Timer B is usually unused but has a lower priority than Timer A. If you do a
lot of stuff in the timer A routine, this will block timer B interrupts
(especially if timer B generates more interrupts than timer A).
The mean thing is that those ROM routines seem to be hardcoded on timer A. So
you can't just put the whole system on timer B and speed up timer A. Maybe
there's someone who knows exactly how timer A is connected to the routines in
ROM and if speeding up timer A just influences on the sound output.
Gunther
|
|
Message has 1 Reply:
 | | Re: Interesting BrickOS Timing Results
|
| OCRA and OCRB are output interrupts for the 16 bit timer. They can be programmed to fire at specific points along the timers run. So, technically, they cannot be used independently of each other. If OCRA resets the timer value back to zero, then (...) (21 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
|
Message is in Reply To:
| | Re: Interesting BrickOS Timing Results
|
| Joe, That's definitely an improvement! So, that would be a 250 Hz sample rate for any given sensor. I just tried a modification similar to yours that did all 4 conversions every OCRA/B interrupt (or 1 KHz sample rate) and got: IDLE: 82 2ROT: 77 (...) (21 years ago, 15-Jan-03, to lugnet.robotics.rcx.legos)
|
19 Messages in This Thread:
 
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
This Message and its Replies on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
