Society of Robots - Robot Forum

Software => Software => Topic started by: Hasan999 on March 05, 2010, 03:11:58 PM

Title: Need help using 8 bit Timers
Post by: Hasan999 on March 05, 2010, 03:11:58 PM

Axon Microcontroller - using Webbot Library...

When I include an 8 bit Timer for any "bank", it compiles successfully, but the programming doesn't do anything (none of the servos get pulses)

Example:

Code: [Select]

servosInit(&bank1, TIMER1_COMPAREA);
servosInit(&bank4, TIMER1_COMPAREC);
servosInit(&bank5, TIMER5_COMPAREB);
servosInit(&bank2, TIMER3_COMPAREB);
servosInit(&bank3, TIMER1_COMPAREB);
servosInit(&bank6, TIMER3_COMPAREC);
servosInit(&bank7, TIMER5_COMPAREA);
servosInit(&bank8, TIMER3_COMPAREA);
servosInit(&bank9, TIMER4_COMPAREA);
servosInit(&bank10, TIMER4_COMPAREB);
servosInit(&bank11, TIMER4_COMPAREC);
servosInit(&bank12, TIMER5_COMPAREC);
servosInit(&bank13, TIMER2_COMPAREA);  // <-- 8 bit Timer

When I searched for related questions, I got to know that 8 bit Timers have lesser "Steps", please correct me if I'm wrong: the servos can attain 13 specific positions? ..is it like that?

Even if so, I need to use 8 bit Timers (along with all other 16 bit Timers), since I have to have minimum number of servos in each bank* (hence I need more banks, with more Timers).

*otherwise, the servos do not hold tight ! (1 servo per bank = perfect)

Need help to get the 8-bit Timers work..

Thanks a lot..

Title: Re: Need help using 8 bit Timers
Post by: KurtEck on March 05, 2010, 07:07:56 PM

I remember the discussion.  I know the current version that I have does not allow servos to use an 8 bit timer (I verified that by looking at servopwm.c).

I think in the end he said he might consider it.

Kurt

Title: Re: Need help using 8 bit Timers
Post by: richiereynolds on March 06, 2010, 03:38:58 AM

Here's the thread -

webbotlib and 8 bit timers (http://www.societyofrobots.com/robotforum/index.php?topic=10310.msg78889#msg78889)

Title: Re: Need help using 8 bit Timers
Post by: Webbot on March 06, 2010, 01:36:02 PM

@Hasan999

I won't be doing anything in WebbotLib until there are answers to the outstanding questions on your original post @ http://www.societyofrobots.com/robotforum/index.php?topic=10113.msg79612#msg79612 (http://www.societyofrobots.com/robotforum/index.php?topic=10113.msg79612#msg79612)

Notably:-
As Admin has said:- "you're supply will need to be capable of providing 22+ Amps".
Your earlier posts suggest you are using a 6v 3300maH battery and that it causes the processor to reset as soon as there is any load on the servos.

Others have said why this would be the case. ie a fully charged battery showing 7.2v with no load will NOT be 7.2v under a load - and that's your problem.

Things still point to your power supply being THE major problem. If I allow 8 bit timers to be used then this will NOT go away.

Equally you haven't answered Dunks very relevant question on that thread - which is a re-wording of an earlier question from me that you also never answered.

Look forward to your responses on that thread; since this is a kinda duplicate.  :)