@angelatlarge yeah, I mean, you need to always define them that way.

@Kortuk Oh? Is there a reference for that? I don't understand why a normal SRAM variable should be treated differently than register variable for the purposes of access/update.

@angelatlarge I am sorry, I dont have a reference, at some point in a 3 year span i think I remember reading that

Really, though, being a register should make the same thing happen.

@Kortuk OK, cool, thanks.

Glad I was not the only one that saw that.

@Kortuk Cute. I don't think Tony reads Mr. T. reads meta

@angelatlarge haha

@angelatlarge Registers should be volatile because their value can change outside of normal program execution. Internal SRAM is only accessed via code, so it can be non-volatile.... the exception that comes to mind is variables accessed in an interrupt - those need to be volatile as well.

@W5VO But if you declare a variable as register, I don't see why you should have to do that.

@W5VO as in register uint8_t myVar;

@angelatlarge Is register standard C? I can't remember

@W5VO I think so. It's suggestion, like inline

register != volatile

@W5VO Exactly.

@W5VO But in any case, I found some other problems with my code (stray leftover break from when I had a switch(), so I might be wrong on this volatile thing.

The point of register is to suggest to the compiler that it should optimize the use of that variable. The volatile keyword makes sure that reads and writes to a variable are not optimized out

@W5VO Yeah, I just don't see why a register variable should behave differently from a regular SRAM var for the purposes of volatile.

I think you guys are talking about two kinds of registers. The register keyword means to keep a variable in quickly-accessible location rather than in main memory. There's no reason this kind of variable needs to also be volatile. When @Kortuk said all register variables should be volatile, I think he's talking about peripheral control registers and things like that, which might be changed by the hardware outside of the control of your code.

@ThePhoton Agreed. I think ports are declared volatile in header files for instance

This chat has really drifted off-topic...do any of you guys get Gordon Biersch beers where you are?

@ThePhoton :) Don't know. I mainly stick either with a) my own beers or b) the cheapest stuff you can buy at TraderJoes :)

@ThePhoton no, I don't think so.

@angelatlarge Where I am, TJ's house-brand beers are brewed by Gordon Biersch...but I think that's a local thing.

@ThePhoton Here some TJ's beers are Unibrowe (which is fantastic) - they are based out of Montreal. But this is for higher-end beers. I but the $4/sixpack kind :)

I but -> I buy

This style bottle uses a "TJ" logo that's a variant of GB's usual logo.

@ThePhoton You're making me want a beer

Anyway GB beers are usually good but nothing special, but I had a seasonal this afternoon that was really good.

@ThePhoton What was it?

"Prost" --- a heavier-than-usual lager.

Has anyone done any SPI on AVRs? Why would while (! SPSR & (1<SPIF))); never return? My SS line is set to output, I am pretty sure: DDRB=0xFF;...

@angelatlarge You got the volatile thing sorted out? Because this is one of those cases where you for sure need volatile.

@ThePhoton Yeah, that's a different issue (he says... confidently...)

And you know why you are using "&" instead of "&&"?

(I'm asking general questions where bugs are likely, because I don't know the specifics of AVR's SPI controller)

@ThePhoton Because bitmask

@ThePhoton I've never used the "because NOUN" construction in all seriosnes before, but that was fun :)

OK, and you really mean "<" instead of "<<"? Because for a bitmask I'd more expect << there.

@ThePhoton Ah, you are right! Let's see if I made the same mistake in code...

@ThePhoton Crap. I did not.

In that case it looks like your SPIF bit is never going high.

@ThePhoton Apparently.

Also your parentheses don't balance... but I doubt it is that way in your real code cause you'd get a compiler error.

@ThePhoton true 'dat.

@ThePhoton yes, sorry, for a moment I knew my brain was failing me.

@ThePhoton no, are they good?

@Kortuk Usually good but not great. But the "Prost" seasonal is a step up for them.

@ThePhoton What's the season?

@angelatlarge Not really sure, but it says "seasonal" on the bottle.

interesting

Damn. Can't get it to work. Will make a question out of it.

Hiya@RogérioPaludo. Unfortunately, you probably can't talk here: you need 20 rep for this, right?

Oh, I am an idiot.

Never set the master/slave select it correctly

Was that wrong?

I think that was wrong...

@W5VO Thanks, but I feel like a dirty whore now.

@angelatlarge I don't even know what to say about that question

@W5VO I need a shower. I can't believe I got rep for that.

@angelatlarge I'll be honest, I think you handled that well.

so I wouldn't feel too bad

@W5VO I suspect not everyone will agree with you on that. I imagine a few people might prefer -4 votes, closed question in 10 mins, plus a couple of Mr T-style comments.

@angelatlarge Everyone's a beginner at some point. Stupid questions only seem stupid after you know the answer

@W5VO Oh, I agree.

At any rate, as long as duplicates get closed, there's really no issue with having questions like these and non-condescending and clarifying answers.

@W5VO Unless people thing that the quality of the whole board is going down and leave or something.

thing->think

@angelatlarge fyi, you can go back and edit your posts here for a minute or so after you post. Click near the left of your post for the drop-down menu.

@ThePhoton Oh, is that how it is done?

@ThePhoton Thx

Just submitted my federal taxes. Time for a cold drink.

That GB thing?

@ThePhoton Congrats!

@angelatlarge or press the up arrow on your keyboard

@W5VO Oh wow. Even better

@W5VO Oh, yeah, but that always annoys me cause I'm usually pushing the up arrow to try to scroll back in the transcript.

@ThePhoton me too, just click on transcript and it works.

@angelatlarge and you can talk to me here about migration stuff if you want me to clarify.

@Kortuk I thought the proposal was just to add certain sites to the list of cites to suggest migration to for "off topic" flagging, no?

@angelatlarge no, he is asking the close migration button have sites on it. wait, let me check, maybe I misread.

They asked for me to pull the same stats as before again.

@angelatlarge look at the picture he shows of another site, that is the close menu.

I think the flag, this is off topic should migrate to... xxxx is a good idea, you can select anything, then we can compile stats on how often the community suggests it.

@Kortuk Ha!

@Kortuk It is a Flagging option, it says "Closing" for got knows what reason

@Kortuk Like me, he doesn't have the rep for close votes.

@angelatlarge it is the same format if you get it it with a close or with a flag.

@Kortuk If I click Flag -> it doesn't belong here, or it is a duplicate -> off topic that's what I get.

@angelatlarge will bet they populate from the same place, I know that menu wont change without reason.

@Kortuk So yeah, I assume that this goes to the mods, and would be nice to have some useful links in there. Just for lazy bums like me.

@angelatlarge Yeah, I just checked, if I vote to close as off topic or flag as off topic i get the exact same screen, that is annoying.

I am betting if one changes they both do.

@Kortuk More likely.

@angelatlarge I am asking someone that knows better.

so i definitely missed the flagging part, that is an issue with me never seeing the flag menu, sorry about that @angelatlarge and thanks for clarifying.

@Kortuk np

hey all

@Kortuk sorry about bad connection last night

@Kortuk did you go on that arduino hangout?

@Rick_2047 No, I had a friend come over and the work calls started not long after that. I meant to get the time from chat but never got to it with people over and such.

oh

any news about what happened on there?

Sorry, when I came back to chat I missed 244 messages, so probably was some news, but not that I read as it missed so much.

can you link me to the chat @Kortuk

@Rick_2047 I meant I missed 244 rooms in here, or do you mean the arduino chat room?

oh, here

the arduino site did reach 100% commitment

@Rick_2047 awesome.

@Kortuk sarcasm?

@Rick_2047 no.

@Rick_2047 it was only maybe 10 or 15 people away at 11am.

it had enough net members, it just needed 10 or 15 more with at least 200 rep on network.

@Rick_2047 I think people believe I hate the site or something. I just think it is a duplicate and will be bad for this site and not be that different, but I also dont think I am always right, we all make errors, and luckily I dont have to be the one under the gun on this decision.

lets just see what happens

@Kortuk if the site starts and they see that its just exactly the same info will it even then be deleted as a duplicate?

@Rick_2047 that is what I was already doing.

@Rick_2047 no idea. That would be my guess.

@Rick_2047 but I assume it is more complicated then that. How do you really decide if it is duplicate, and then would removing it really just move the community over. Dunno, I like leaving things like that for the SE team to decide.

As I would say normally, above my pay grade.

@Kortuk yeah, definitely above your paygrade

lol

:) volunteer work makes it super easy to say that

@Kortuk have you ever taken advantage of this mod work? putting it on CV or such

or going to parties and saying "i am a big deal on the internet you know"

@Rick_2047 Hey, if this were the internet I would just delete your comments sir.

@Rick_2047 honestly, almost every interview i have been to they ask my hobbies.

and telling someone, I play video games is not a good hobby.

This would be the hobby I mention and discuss, beyond that, no, I dont use it.

Constantly seeing peoples problems is good for the brain though, imho.

I have just now started to gain confidence to answer questions or edit questions and answers

@Rick_2047 ha, it takes time.

@Rick_2047 and communication skills are often the biggest thing we lack as engineers, this is a good place to practice those.

oh no, I am not at all concerned about my communications skills.

this is parhaps the best skill that I have

@Rick_2047 my written skills always need help. I am a very sociable person, I like talking to new people and generally become friends with people all over, but expressing a technical point clearly can be much harder from my perspective.

@Kortuk strange, you gave me the best advice for technical writing

Wow a rash of questions.

@Rick_2047 making it up?

@Kortuk no, "use numbers"

my reports are more appreciated now

i use lots of tables and real numbers

@Rick_2047 haha. Sorry, that is one of the best pieces of advice I have ever been given, and I get it often.

@Rick_2047 I wish my emplyees took to that advice so easily.

@angelatlarge gotta be careful with those spellings

although, occasionally knowing which numbers are of interest is not the easiest.

@Rick_2047 What do you mean?

@Rick_2047 I think he meant rash :)

rash ~ rush

@Kortuk I think both were appropriate

no, i mean electronics.stackexchange.com/questions/64735/…

@Rick_2047 haha

@Rick_2047 No, I meant that too

I jsut found that one

@Kortuk lol

Why, does it read dislexic or something?

I meant i just found the comment. I am too tired.

I am going to bed, night guys.

@Kortuk Good night!

@Kortuk good night

night guys, chat in the morning.

Can anyone tell me what am I doing that's stoopid? Why are my LED drivers only producing output when I hold the BLANK line in my hand: not when it is LOW (like it is supposed to be to NOT blank), nor when HIGH (that's one's expected). What am I missing?

which driver?

@Rick_2047 TLC5940

@angelatlarge bad connection. needs to be decoupled. It was cold and needs your love.

now I am sleeping

@Kortuk Something's badly connected, one would think.

@angelatlarge, pure speculation but on the block diagram it's close to GSCLK, maybe you have a problem with that, how is it driven?

@Kortuk YOu think the led driver might need a decoupling cap? I don't get why would my body capacitance help

@PeterJ Yeah, the clocking of that thing is a PITA. I set a fuse on my AVR to output it's internal clock on a pin, and that is how GSCLK is driven

@PeterJ Or should be... I am double-checking all the pins one by one, about to check the GSCLK

Yeah it is connected to ATmega328 pin 14, CLKO

Maybe I should mention that this is actually 3 TLC5940s. The BLANK line is shared. In fact all the lines are shared except for SIN, which is daisychained.

And they all turn on when I fondle (@Kortuk) the BLANK line

Hello people. Busy day so far, couldn't come online. What's happening?

@AnindoGhosh Hiya Anindo

@AnindoGhosh Me? Trying to debug the TLC5940 issue you see above.

@angelatlarge Do you have a scope to see what those clock lines look like? I had a vague idea that the CLKO had something odd about it, although looking at the datasheet it doesn't seem to back it up, maybe I'm thinking of another processor

Hi @AnindoGhosh

@AnindoGhosh But the SPI load seems to work nicely.

@angelatlarge So you're saying it doesn't clock right, or it doesn't latch right? Sounds like the latter.

@PeterJ Oh really? I have an ancient scope, or a Bus pirate hacked to be a logic analyzer.

and... hi @angelatlarge and @PeterJ

@AnindoGhosh Mmm... the LEDs are BLANKed unless I hold the BLANK line in my hand - somehow my body capacitance makes it ... go?

@angelatlarge, I'm thinking of something I did years ago, but I can't remember if now if it was an AVR or something else and possibly I was using one side of the XTAL oscillator not CLKOUT. Looking further for the ATmega328 it looks like it's all buffered just like any other I/O line.

@PeterJ What I can't figure out from the datasheet is how (whether) there is padding necessary.

@angelatlarge Here is some unsolicited advice: Separate the problems. In this context, that means drive the TLC parts slooooowly using some separate code, injected by any means you can, since the TLC can be run at slow clock speeds. See if the issue exists / persists. Then get back to your high speed code.

good morning

@AnindoGhosh Well, it was working before with my ultra-high-speed bitbanging code :)

@jippie jippie!

@jippie Hiya old man!

I think I pulled a string in my shoulder yesterday trying to bit bang my 8 digit LED display

@jippie Like a ham string?

@jippie I can't tell what you mean and if you are trying to joke or not.

@angelatlarge Try separating the problems nevertheless. Divide down all relevant clocks if you must, after the isolated testing. That way a bus pirate can help you diagnose if there still is a problem.

I'm not joking, my shoulder/back/muscle hurts.

@AnindoGhosh Yeah, that's probably true. But body capacitance de-activating the BLANK line: it has to be something electrical, right?

@jippie I think here we say "pulled a muscle" or "pulled a ligament" or something...

@angelatlarge, how many of the devices will you be producing? Just thinking you already have 10 components (or is it 8) that solve the problem.

Then, bring the clock and data speeds back up, see if there's some interference, coupling etc happening due to signal toggle speed. Also, decouple each chip heavily close to its Vcc / Gnd. If you have LEDs hooked up, a turn-on is bound to dip the chip's power noticeably.

@angelatlarge Assumption is the mother of invention - not!

@angelatlarge touch = go implies decoupling as first thing to check. Both Vcc decoupling, and caps on the lines that aren't supposed to switch around. They could perhaps pick up noise.

@angelatlarge but you're spanish

@jippie No, I am from Tlarge

I know, Tlarge in Spain.

@AnindoGhosh Decoupling caps added on the LED drivers (they were already on the ATmega), touch behavior the same.

I need to go to bed.

BUT, timing wise the SPI code seems to work great.

Got it down to 89% of the required time. Yeay for parallel processing!

@jippie Sorry, I cleaned up on all the easy rep today.

@jippie I feel like a whore

@angelatlarge Ah!! I love that feeling, don't you?

@jippie :)

@jippie I am still LOL

Goonight all. Time to go night-night.

?

it is 09:38

In spain?

yes

@jippie It is nearly 04:00 in Tlarge

I love loading AVR programs over bluetooth. Soooo nice.

that is a normal time for @AnindoGhosh to wake up

@jippie Yes if T'Large had slept till then

@angelatlarge sorry mis-tabbed there

@angelatlarge which reminds me I wanted to try if I can connect a bluetooth GPS receiver to my Arduino

@jippie @AnindoGhosh is a robot. Probably run by Induino inside.

OK, my first goal today is to find the bleutooth master module that I should have somewhere ...

good night @angelatlarge

I just need less sleep than most, is all.

Also, I log in from mobile devices, from all over the place, hence am online a lot.

@Angela Also, what I do primarily is something far removed from technology, and my field of work requires odd hours and long schedules.

@AnindoGhosh do you know from the top of your mind how I can attach a routine to a timer interrupt? I want to execute a routine every 1ms or so

there was something with what timer to use

never mind, I have it working.

@jippie I use Timer1 for high precision counter and Timer2 for all others, I don't use Timer0 ever

@AnindoGhosh, I agree, if zero was meant to be used for timing we'd have 0BC and 0AD

@PeterJ Hehehehehe

@PeterJ ?

@jippie, reason I said it was I remembered this was starrred for a while (not sure how to link it properly) but:

But other than that or needing over 8 bits can't think of a reason not to use (apart from I think the Arduino uses it for other stuff by default)

/me shrugs

otherwise if you have no religous objections I'd use timer0 if other requirements are OK ;)

@PeterJ I guess Arduino is a religion then.

Yes and the dark side at that, shields should be either electomagnetic protection or medieval armor

You can still buy it:

armstreet.com/store/armor/…

@PeterJ My reasoning for avoiding Timer0 is, many third party libraries default to the first timer, so I prefer to leave that for something that comes up later.

@PeterJ It's not arduino-specific, I use the same rationale for any MCU - don't use the first available resource if the second / third / n'th would serve my purpose, thus saving effort later if I want to use someone else's code that hasn't been so considerate :-)

@AnindoGhosh, OK I'll believe you for the moment. Secretly though I think you might avoid going anywhere of Friday 13 and full moons etc.

@PeterJ Friday 13th, I don't even understand why people consider it special. Full moon, different story - it's my favorite night of the lunar cycle for night photography (Google my name, you'll understand the context).

Will do in a sec, I'll also see if I can find one of my moon shots although don't have a lens over 400mm equivalent so not too impressive.

@PeterJ I've posted a couple of moon images shot with 500 mm lenses, but it's not images of the moon that interest me, so much as images in moonlight. I specialize in available-light photography, both for my commercial work, and for my exhibition imagery.

@AnindoGhosh, just was a bit side-tracked but very nice from what I've seen so far.

@PeterJ Thank you :-)

@AnindoGhosh, love some of your artistic work. I catalog my photos about as well as I comment source code but here is about my best attempt at a moon shot I could spot, not as crisp as yours... i46.tinypic.com/6rn2o9.jpg

@PeterJ nice. The moon naturally looks a bit more yellow, I hate what digital camera AWB does to it. One of the few situations where I still prefer film.

I've used film before but at that stage growing up given the cost of developing wasn't really into photography much other than the usual holiday snaps. Agree though even with new DSLRs AWB (and all other auto things) aren't so good so as I learn more try and do everything as much manually as I can.

@PeterJ I'm a heavy consumer of 35mm c41 film.

I've got great respect for film photographers. It's nothing now to fire off a few thousand shots for a handful of 'keepers'. Guess now it costs $10 (shutter actuations etc) not the thousands before it would have taken to try

'random' shots

Anyway about to head off, catch you later

@PeterJ Bye!

@AnindoGhosh now you sound really old ancient

LED's in parallel is a bad idea due to thermal runaway, what happens with zeners (3V3) in parallel?

Hmm ... they apparently both have a negative temp coefficient.

@jippie same problem

I want circuitlab available in chat!

My bluetooth master requires 3V3 @50mA. When I make a 3V3 series resistor, zener shunt the 5V voltage range is so small (4.3V - 5.3V).

and my Arduino Mega can max. supply 50mA @ 3.3V. I don't like the tiny margins.

I think I should get myself some low drop regulators

neh .. same zener voltage. tnx

@CamilStaps they will suffer from thermal runaway because of the negative temp coefficient

@CamilStaps thermal runaway is when two diodes (eg. LED's) are in parallel. One takes a little more current than the other and heats up a little. Due to that the current will increase and it will heat up a bit more. So one diode is 'stealing' current from the other one and the balance gets worse and worse and worse ...