Search found 46 matches

by SJHardy
Wed Jul 10, 2024 4:59 pm
Forum: Hardware Interface Issues
Topic: Not getting 3v3 PWM output on JP6 pin 5 (IO26)
Replies: 5
Views: 22

Re: Not getting 3v3 PWM output on JP6 pin 5 (IO26)

I didn't realize the 150 ohms were pull-downs, I assumed they were series termination. That explains the lower voltage. It seems we get about 300mV drop from the rail. Our guys doing the board assembly normally put the jumper for 3v3, but it's possible that mistakes were made in which case it would ...
by SJHardy
Tue Jul 09, 2024 11:05 pm
Forum: Hardware Interface Issues
Topic: Not getting 3v3 PWM output on JP6 pin 5 (IO26)
Replies: 5
Views: 22

Re: Not getting 3v3 PWM output on JP6 pin 5 (IO26)

The J2 jumper sets 2.5/3.3V for "comm". Would that affect the PWM outputs too?
by SJHardy
Tue Jul 09, 2024 7:45 pm
Forum: Hardware Interface Issues
Topic: Not getting 3v3 PWM output on JP6 pin 5 (IO26)
Replies: 5
Views: 22

Re: Not getting 3v3 PWM output on JP6 pin 5 (IO26)

So, not a software fix. Oh dear. Is the actual driving chip TTL, or is it CMOS pretending to be TTL? I assumed when designing our breakout board that it was CMOS and hence high and low levels would be very close to supply if terminated by infinite impedance (regardless of conservative manufacturer s...
by SJHardy
Tue Jul 09, 2024 5:37 pm
Forum: Hardware Interface Issues
Topic: Not getting 3v3 PWM output on JP6 pin 5 (IO26)
Replies: 5
Views: 22

Not getting 3v3 PWM output on JP6 pin 5 (IO26)

Hopefully a quick one: I expected IO26/PWM0 to be a push-pull drive, so should get 3.3V pk-pk, however we are seeing only about 2.3V pk-pk, and about 200mV of noise on top of that, during the high output state. Only noticed recently because mostly we have fairly slow spindles, but the one we are usi...
by SJHardy
Wed Apr 03, 2024 5:29 pm
Forum: C Programs
Topic: Kogna debug suggestions
Replies: 41
Views: 1066

Re: Kogna debug suggestions

While I can't cite chapter and verse of the C standard, I'm pretty sure it should not be making any assumptions about what functions do. If the CL6X compiler is really assuming the value is unchanging through the loop, that's definitely a compiler bug. I seem to recall reading that the compiler must...
by SJHardy
Wed Apr 03, 2024 3:58 am
Forum: C Programs
Topic: Kogna debug suggestions
Replies: 41
Views: 1066

Re: Kogna debug suggestions

Is thd_function defined to be volatile? No, but I don't think the compiler should be optimizing that out since it doesn't really know what Delay_sec() might do. I probably should declare the "supe" pointer as pointer to volatile, which would remove any question in this and other cases, but at prese...
by SJHardy
Tue Apr 02, 2024 8:01 pm
Forum: C Programs
Topic: Kogna debug suggestions
Replies: 41
Views: 1066

Re: Kogna debug suggestions

I've finally had a bit of a breakthrough. As described before, my homing procedure runs in thread 2, while the supervisor continues to run housekeeping in thread 7. But in addition, thread 1 is a stub program that launches the homing procedure (by executing thread 2 via the supe->ref_axes() call lis...
by SJHardy
Tue Apr 02, 2024 7:00 pm
Forum: C Programs
Topic: Kogna debug suggestions
Replies: 41
Views: 1066

Re: Kogna debug suggestions

Hi Tom, What is the resolution of TIMERLL0? I couldn't find doc. for it in the TI literature. Until now, I didn't realize the resolution of Delay_sec() might be in the microsecond or better, but I'm thinking of replacing some ad-hoc delay loops in my code to consistently use the firmware function. I...
by SJHardy
Sat Mar 30, 2024 12:44 am
Forum: C Programs
Topic: Kogna debug suggestions
Replies: 41
Views: 1066

Re: Kogna debug suggestions

Q: how does one coax CCS into allowing breakpoints to be set by C program/line number? At present I can step through, and it highlights the C source line correctly, but breakpoints can only be set on known symbols, which forces me to create dumb little functions all over the place. If I try to set o...
by SJHardy
Fri Mar 29, 2024 7:15 pm
Forum: C Programs
Topic: Kogna debug suggestions
Replies: 41
Views: 1066

Re: Kogna debug suggestions

I already have a user callback that is used to get accurate time stamps for certain input bit changes, such as touch probe measurements. I think it's a good idea to add a sanity check in there. The only problem I can see is if IER[6] was turned off, then it would never get inside the user callback s...