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MLM
12:32 AM
Anybody know of a inline usb protection cable from overcurrent/voltage - Already had a previous laptop get destroyed and don't want it to happen again. I saw this topic electronics.stackexchange.com/questions/64321/… but I am wondering if there are already pre made solutions
 
@MLM I wouldn't know.
 
cpf
1:00 AM
hmm
 
@cpf: So which kind of connection are you using?
 
cpf
between the ISP and the target?
 
@cpf Yeah. The one without the crystal, right?
@cpf BTW, I have really crappy internet now, so I might disappear for a few at any point :)
 
cpf
yeah, I'm connecting the NG and Uno boards as shown in that diagram
 
@cpf But you are not programming an uno, just 328p right on the breadboard, or did I misunderstand that?
 
cpf
1:03 AM
well, I tried both ways
 
@cpf So on the barebones setup, you are not connecting a crystal or anything, just the power lines and the ISP lines, right?
 
cpf
first with the 328 in the NG, then - a large number of iterations later - I tried all of the chips on a breadboard, sans crystal/caps/etc, yes
 
And you tried both RST with pullup resistor (as on the right side) and without the pullup resistor (like on the left)?
 
cpf
only the left-hand configuration, didn't spot that resistor
 
Give it a shot. It's a longshot, but try it. You really shouldn't need the external Xtal: the factory chips come with fuses set to internal oscillator, but not holding the reset line high until you program might be a problem. So try it with the res.
However, given the variety of targets you have tried, the more likely problem (IMHO) is with your programmer, the NG.
@cpf BTW, you saw this right " On the Arduino Uno, you'll need to connect a 10 uF capacitor between reset and ground (after uploading the ArduinoISP sketch)"?
@cpf For when you are using the Uno as the programmer.
 
cpf
1:13 AM
Yeah, I've tried both with the NG and Uno as programmers
and: just tried with the resistor, same result
 
@cpf Right. Wait, so you can't program the NG, according to that website, because you can't get to NG's reset pin. So in theory, you should only be able to program the Uno from the NG, or the bare bones chips from either.
 
cpf
well, you can manually hold the digital 10 out onto pin 1 of the IC when it's in the NG
doesn't help
 
@cpf Wait, I think it's the cap issue.
@cpf Right, the cap is necessary (I thin) so that your programmer itself doesn't reset.
@cpf Tell me you didn't put in the cap when you were using the Uno as a programmer, right?
@cpf right?
 
cpf
well, I don't have any 10uF capacitors kicking around, but I tried with 100uF to no avail
 
@cpf OK, so the cap needs to be in place after you've programmed the Uno with the ArduinoISP sketch: you put that in right before you use the Uno as the programmer.
 
cpf
1:24 AM
yeah, that's when I put it in - same error
 
Hmmm.. let me think for a sec...
Actually, this is the link I had in mind:
3
Q: How to burn atmega328 chip via Arduino UNO as ISP?

user3124I've an atmega328 chip (without bootloader), and I want to burn it with my Arduino UNO as ISP, so I can have a spare atmega 328 with UNO bootloader. I'm trying to follow the instruction in http://arduino.cc/en/Tutorial/ArduinoISP, but there is a note that said: Currently, you cannot use an...

 
cpf
though that note is no longer visible on the page
 
These guys suggest a resistor to the reset line of the programmer: this will prevent it from going low at all.
"if you put about a 120 Ohm resistor from reset to 5v on the UNO then it'll work. "
Give that a shot.
 
cpf
I've got a severe deficit of 120 ohm resistors
 
What do you have?
It really doesn't need to be exact
 
cpf
1:35 AM
10k, 1k, and if my eyesight is to be trusted, 330 ohms and 470 ohms
 
Take the two (or three) 330ohm ones, and use them in parallel.
Three is better, but if all you got is two, then that will do.
330 is orange orange brown.
I don't know exactly how the reset line is wired up on the Uno, so I don't know exactly what kind of current we can pull from that, and how stiff it needs to be, so I am shooting for something close to what was specified in the post.
 
cpf
yeah, just tried that, same error :\
 
Really? Crap.
That should have fixed it, I would have thought.
You are trying to program the NG or a barebones chip?
 
cpf
barebones atm
 
You probably triple-checked your wiring, and that the chip is seated correctly, not upside down, all that stuff?
 
cpf
1:42 AM
yep, I've taken it apart and put it together many times by now
 
How did you check the connections?
 
cpf
to the...
 
It's useful (I think) to get your entire set up actually set up, and then touch the connection andpoints continuity probes: this makes sure all the wires and the breadboard connections are good.
So I'd make sure that ATmega pins are connected to ATmega pins (UNO to barebones).
@cpf I have to run off soon. Maybe you want to add the whole capacitor/resistor thing to your question so that everyone knows?
@cpf Take care!
bye all
 
cpf
yeah, will do
thanks for your suggestions
 
2:18 AM
Good morning :-)
 
3:07 AM
I wish comments could be voted down.
 
3:38 AM
@Bitrex They can be flagged for moderator attention. Which comment?
 
3:59 AM
I can't figure this out... what is the difference between TPIC6595 and TPIC6596? Besides the value 1, of course.
@jippie any ideas?
 
@AnindoGhosh Looking at the logic diagram on page 2 of both datasheets, it looks like the CLEAR behavior is different.
 
@ThePhoton I was wondering about precisely that... why one and not the other in a given application?
 
@AnindoGhosh Got me
 
@ThePhoton With two parts so similar, good usability dictates that the datasheet writers specify the application distinctions right up front when they are extolling the virtues of the devices.
 
@AnindoGhosh Given who I work for, I'll make no claims about how to write good datasheets.
 
4:06 AM
@ThePhoton In general, TI does make good datasheets.
 
@AnindoGhosh The first way I tried to answer your question was to go to one of the product web pages and look for a table of "similar products" ... no dice.
 
@ThePhoton I went to TI's page for that purpose - evidently they don't see the two parts as sufficiently similar to justify a distinction.
 
@AnindoGhosh Also, remember this part might be old enough that when the ds was written they assumed most readers would have the two datasheets back to back in a data book.
Also, the clear behavior is described in the 2nd paragraph on page 1 of each ds.
 
@ThePhoton Looking at the two back to back, I still don't see why one and not the other.
 
"When SRCLR* is low, the input shift register is cleared. "
in the other one: "When SRCLR* is low, all registers in the device are cleared"
@AnindoGhosh Just depends what behavior you want in your system.
 
4:10 AM
@ThePhoton hmm. thinking about it.
 
Maybe different designers have different philosophy about how restets should be used --- some just want to put the communication buffers in a known state, others want to reset everything, including the outputs under control.
 
@AnindoGhosh Is there a price difference?
 
According to the ds revision history, the '95 was released in 1992 and the '96 wasn't released until 2000.
Maybe they had a big customer tell them, "I want the CLEAR signal to do this:..."
 
@W5VO nope
@ThePhoton rotfl
I just sent off a mail to the TI engineering support team, let's see what they have to say.
 
@AnindoGhosh I assume to get a positive response from TI on a request like that you've got to really be a BIG customer.
@AnindoGhosh Where I work we've got customers who could tell us to stand on our heads while we build the parts, and we'd do it.
They'd be buying foam head rests for every operator on the line within 24 hours.
 
4:19 AM
@ThePhoton Actually neither of those is a TI original design, from what I can make out. There are equivalent historical parts, 595 and 596, from other manufacturers. This leads me to think there's something critical I'm not getting about the distinction.
@ThePhoton The TI innovation is the TPIC6A595 etc. Look at the current rating on the 6A*** beasties!
The TPIC6A595 can be used pretty much as-is as a motor driver, it even has high shunting clamps at 50 Volts, so no snubber needed. Amazing to have logic+power integrated like that.
@rawbrawb Interestingly, Tourette's Syndrome is commonly abbreviated as TS. An epiphany!
 
Doesn't answer your question, but gives an idea what they designed those guys for.
 
@ThePhoton Ah HAAAA! "parallel 3-state ('595) or open-collector ('596) outputs"
 
In the app note I just linked: "The TPIC6C596 is an enhancement of the TPIC6C595, where the shift
register serial output (SER OUT) is clocked on the falling edge of the serial clock to provide
additional hold time in applications where several devices are cascaded"
 
@ThePhoton Interesting, that isn't the same as what the SN...595 and SN...596 are distinguished as.
@ThePhoton So OK, if I go by TI's appnote, then I now know why do use one as opposed to the other.
Ouch, that's a terribly messy sentence construct: then I now know why
 
@AnindoGhosh Also doesn't seem to be the same difference as TPIC6596 and TPIC6596.
 
4:30 AM
@ThePhoton Yes, the A/B/C variants are clearly TI enhancements, and those enhancements may have diverged from the original design brief.
 
@AnindoGhosh I would have assumed the A/B/C are for different load currents...having the logic behavior also change is con-fuse-ing.
 
@ThePhoton I agree, but that's how it is - they've changed more than just triggering condition.
 
I am on a roll with low-vote answers, +9 for my last 7 answers :<
 
They have an entire family of power+logic parts... ti.com/paramsearch/docs/…
@ThePhoton Low-vote has been the norm for the last couple of weeks. Change in the weather perhaps.
 
@AnindoGhosh I already clicked there to see if the parametric table would be elucidating ... unfortunately not
 
4:34 AM
@ThePhoton I'm going to sample a bunch of them to check what works and how.
 
@AnindoGhosh Look like interesting devices for pyrotechnics sequencing...
 
@ThePhoton I'm looking at them for model railroad scenics animation - the several motors needed for a single complex animated object.
@ThePhoton How would I use those to make a H-bridge arrangement, need to think about that. So that I can control motors and reverse them in sequence.
 
@AnindoGhosh Doesn't H-bridge need both a high-side and a low-side switch?
 
@ThePhoton Yes, and that is why I'm having to think about it.
I mean, I could of course just use bunches of H bridge ICs. However, being able to serial-in-parallel-out with 8 bits at power drive current levels is very attractive.
 
5:13 AM
good morning
 
Heya @jippie
 
5:30 AM
Hallo all
 
5:46 AM
did you find the difference @AnindoGhosh?
 
@jippie triggering edge.
@angelatlarge hiya
 
:)
 
 
2 hours later…
7:35 AM
@MLM, it might be a bit over the top for what you need but I bought one of these a while back for debugging a system where the JTAG ground (and hence programmer) was at mains levels au.element14.com/analog-devices/eval-adum4160ebz/…
Hi @all
 
7:46 AM
@PeterJ hello
Goodnight all
 
@angelatlarge, hi and bye at the same time by the sounds
 
 
1 hour later…
8:49 AM
hi
 
9:15 AM
Hi @Peter and @Rick
 
Hi Anindo, back a bit later, time for dinner :-)
 
9:57 AM
@AnindoGhosh what is up these days?
 
10:22 AM
@Rick_2047 Various things. I was out today struggling with the heat and humidity... Gave up on my venture and came back home after a couple of hours.
 
what did you intend to do?
some photography?
 
10:33 AM
I thought he'd be busy sketching up an ASIC bitcoin miner ;-)
 
i have been thinking about it
how hard is it to implement a bitcoin miner on an FPGA?
 
Probably not too hard (relatively) but an ATI GPU graphics card will give lower cost / hassle and faster speeds per $ from all I've seen. That sort of massively parallel integer is well suited to a GPU.
 
11:00 AM
@Rick_2047 No, I was to visit an ultrasonic equipment manufacturer, sourcing some ultrasonic reactors for a client requirement.
Darn, one more vote on one of my answers, and I'll get a new badge. :-)
 
11:19 AM
I guess you could post it here, but what if it gets critical review and lots of downvotes ;-) ?
 
 
1 hour later…
12:19 PM
@PeterJ I'm never too worried about downvotes - there's at least a couple of people who at one time used to downvote everything I wrote, on principle, because of some differences of viewpoint around "real engineering" (theirs) versus "solve the problem" (mine) approaches.
39
A: Heuristic explanation of the usage of a pull-up (or pull-down) resistor needed

Anindo GhoshFirst: Yes, your understanding is essentially correct, other than the issue being voltage and not charge. Here is my analogy: Consider a door to a house, with really smooth hinges, and no bolt or latch. The door is so light and so well-hinged that the slightest breeze would cause it to flap ope...

There we go.
"Real engineers consider it below their dignity to answer silly hobbyist questions, I'll just vote to close instead"... Supercilious ba-*-ds ;-)
Thank you for the upvote!
 
mmm... house analogy? Internets and current are all like tubes.
What was the badge anyway?
 
Yay! Just got the "Guru" badge.
I still don't have any gold badge... Something to work towards :-)
 
Ahh just saw it, congratulations!
 
Thank you thank you. :-)
 
1:27 PM
@angelatlarge No, the accounts dont last long.
 
1:44 PM
@AnindoGhosh morning morning
 
@Kortuk Day day
@Kortuk :-)
 
@AnindoGhosh this is confusing. I feel like I missed something. That question did not have any close votes.
 
@Kortuk No, that was in reference to a long-ago discussion... Not in context of the message just previous.
 
@AnindoGhosh ooh, then I am not as lost now
I was looking at that question trying to figure out WTF am I missing!
 
@Kortuk Oh don't worry about it.
 
1:47 PM
@AnindoGhosh That is something you should report. Revenge downvoting/upvoting is not acceptable. if it seems to be happening tell us!
 
@Kortuk Speaking of which... there was a recent question (not sure which one) where our bearded friend commented about "just using shields and stuff, not real engineering". I was planning to flag it, then I got distracted and lost the question.
 
@AnindoGhosh uhh ohh. This might be a challenge to find, he is very active on the site.
 
@Kortuk Maybe a query string by "Comment by olin" in last 24 hours?
 
@AnindoGhosh I verified, it might have seemed like this happened, but I know for sure no one followed you around and downvoted you.
 
@Kortuk For 3-4 days, every post of mine was downvoted, regardless of content or quality.
Was in the early days too, when I didn't know about the grouch principle.
 
1:50 PM
@AnindoGhosh I can say for sure it was chance, on each post it had to have been different people. If you knew the days I could do a more detailed look for voting rings and such.
 
You're just jealous for only having half a beard Anindo ;)
 
@PeterJ Uhh ohh, the cats out of the bag.
 
@PeterJ This is true. Sometimes the left half, sometimes the right ;-)
 
I'm about to head off, I'll have to post a photo of myself tomorrow and maybe I can get my own nickname
 
@Kortuk You actually believe I'd be bothered any more?
 
1:54 PM
@AnindoGhosh Well, lets be fair here, the thought of a voting ring is a serious concern for me.
 
@Kortuk Why do you think it'd have to be a voting ring?
@Kortuk The Grouch Principle says "If you're not grouchy to people we are grouchy to, we will be grouchy to you".
 
@AnindoGhosh because I know for sure that no single user did it. :) When you mentioned getting every post downvoted I verified no one did that to you. I have some secret tools :)
 
@Kortuk There were some 17-18 single downvotes on posts, this much I remember. A voting ring would have multiple downvotes at least sometimes.
 
@AnindoGhosh nope, many real voting rings found happen to be a well hidden user with many accounts. We can find them, but they are generally not as obvious.
 
@Kortuk Regardless... Back then I used to be bothered because I was also recommending people to the site. Now I'm much more chilled out.
@Kortuk Ahh, ok fair enough. To me that sounds not like a "ring" but like a socket puppet thing.
 
1:58 PM
@AnindoGhosh I just dont like the though of voting rings. If you do ever seem to be revenge downvoted again let me know.
@AnindoGhosh I use ring to be more broad, it could be multiple people or just one. Generally multiple people is harder to find, but we still find them all with time.
@AnindoGhosh I have gone through 2 weeks of comments without finding it, it probably was already nuked.
 
@Kortuk If it ever happens now, I'd (a) be more comfortable passing over it and (b) flag it to you. I'm now aware that real people exist on chat, and also I'm that much less bothered by vindictive grouches ;-)
@Kortuk It was certainly not weeks - it was on one of my open tabs, and I only got back home and started opening tabs on the 2nd April. Then early this morning I did a windows update, so no more tabs.
 
@AnindoGhosh Ha. downvotes should generally be ignored as part of the noise generator on all communication media, but if someone is injecting a DC offset that is targeted at a single person I am going to clean it up to protect the speakers.
@AnindoGhosh Yeah, I did not realize for a moment how long I had made it back, then realized I had gone through two weeks and stopped looking
 
@Kortuk Yep, it's only when there is a DC offset that I even notice.
 
:)
 
@Kortuk Then it's been nuked, which is a good thing - I remember thinking "This is the kind of comment that pisses duinoobs off". I wanted to tell you, but shiny things lured me off.
@Kortuk Wait, did you check closed questions? Because it was a question with 2 or 3 close votes when I opened it. Something definitely containing Arduino and Shield in the question, and shield(s) in the comment.
 
2:06 PM
@AnindoGhosh I checked all of his comments that are not deleted.
 
... and I felt it was a question I would be keen to answer if I had the time.
 
regardless of location
 
@Kortuk Cool.
In just now: Downvote of a newcomer without an explanation...
-1
Q: How to make an LED flashes twice every second?

electronics_dummyI know I can let an LED flash using a 555 timer, but how can I let it flash twice every second?

@jippie, this one's straight up your alley :-)
0
A: atmega32 programming

SuirnderAsad, No you do not need the external oscillator to reprogram the flash.

Uhm I meant the question, not the answer.
 
@AnindoGhosh you are still taking downvotes far too seriously. They are intentionally there to let people know their questions does not show research. That is clearly an example. Before I started posting on the site I took part for quite a while to watch and then took part when I felt like I understood what was going on.
@AnindoGhosh you have to admit, that is a terrible question.
+1 Because it's Friday, and I wanted to compensate for the unexplained -1. — David Kessner 2 mins ago
really? on that crap question?
 
@Kortuk Put yourself in a newcomer's shoes please. Both from question quality and content point of view.
 
2:14 PM
@AnindoGhosh The point of the site is not to tell everyone, "Post your crap," We do want people to feel welcome, but they should not feel like they can just sling crap at us.
 
I think what David did is nice, way more constructive in embracing new members (and then turning them to the dark side)
 
@AnindoGhosh it got what looks like a nice answer, I would consider that more important. I can see that you would like someone to explain why they downvoted.
 
@Kortuk While I'm all for getting people to improve post quality, I deal with newbies in several fields all the time, so I'm much more inclined to educate than to push one button on a power trip. Sorry, I think we'll always disagree on that.
 
@AnindoGhosh yeah, the best way is to edit and improve for them and inform them to try to do more like what example you have made. However, SE as a whole considers just accepting all crap to be a bad decision.
 
@Kortuk I'm never for accepting crap. There's a clear distinction. I'm all for telling someone why their post is crap and how it could be sorted.
 
2:18 PM
@AnindoGhosh So why not write that comment on the post instead of "downvote because..."?
You have to admit you can tell why that was downvoted.
 
@Kortuk Actually, since I've heard almost identical questions in real life many times, I don't read minds enough to tell why it was downvoted.
 
@AnindoGhosh just because someone has asked it before does not make it a well research questions. I can list hundreds of questions people have asked me to avoid doing any research.
 
Your average electronics newcomer doesn't even know what a datasheet is, let alone having read one, ever.
@Kortuk I'm dropping out of this conversation.
 
Yep, that is separate to this. You can find a 555 timer circuit to get you a 1 hz blink pretty easily. Not saying it is instant. But if you know how to get it to blink you are only a step away. Just sharing the schematic of what he had would allow us to easily say, here is the one last bit you were needing.
@AnindoGhosh :( why such a sudden dropping it? I am just trying to discuss.
 
@AnindoGhosh :)
 
2:25 PM
damn, cant remember the latex for what I need to type for camil.
 
@Kortuk That sounds dirty.
 
@DavidKessner haha. good point
 
If the ATmega's fuses are set for using external oscillator, how would one reprogram it without using an oscillator, without resetting those fuse bits?
 
@AnindoGhosh Feed it a clock from whatever circuit is trying to program the chip? GPIO from another MCU?
 
@DavidKessner That's a substitute oscillator... I'm sure the question is about dealing with a situation where one does not have an oscillator available. All clocks are oscillators, ideally - just not crystal oscillators. :-)
 
2:34 PM
@AnindoGhosh Yea, so you need a substitute osc. There is almost always one available, since one is needed by whatever device is trying to do the programming.
 
@DavidKessner So my point is, the existing answer is incorrect: "No you do not need the external oscillator to reprogram the flash."
 
I think that guy wants to reprogram it using the same universal programmer.
@AnindoGhosh It is ambiguous with the current Q. Basically, if the OP wants to reprogram with the universal programmer then the answer is correct, just badly worded.
 
@DavidKessner Here's my concern with that: An AVR MCU typically can be programmed without ext-osc being fed, by many different programmers. However, to my understanding, once one sets the fuses for ext-osc, then the MCU no longer works without such input, for programming or otherwise. Is my understanding wrong?
Basically, the MCU factory settings default to using the internal RC oscillator. Setting fuses for external oscillator disables that. Correct?
 
@AnindoGhosh I do not know about the AVR specifically, but every other MCU that I have used would allow for reprogramming without an external OSC even if the ext. osc bit is set.
 
I'll just google that. I recall reading specifically about not being able to reprogram an EVR once ext-osc fuses are set.
 
2:43 PM
0
Q: Returning Currents for two side boards and returning current questions

user22165I have some questions these are i am not sure exactly: I have designed a board that has classical 2 side PCB design. Frequency is not a big issue for me but with ESD my CPU resets itself. (CPU clock 20 Mhz, and some data transfer lines at 10 Mhz, 2Mhz, 400 Khz ) 1- How is returning current work...

That's a good Q, but for some reason I just don't feel like spending lots of time answering it when the guy uses the default Anonymous username. So much for the "Feeling good, it's a Friday" thing! :)
 
@DavidKessner Yup - once fuse bits are set for external oscillator, one needs a high voltage programmer to program the MCU if external clock is not available.
 
@AnindoGhosh I would assume that a "Universal Programmer" is a "High Voltage Programmer". Would that be wrong?
 
@DavidKessner I think wrong
 
Sounds like the AVR has some sort of internal charge-pump that requires a clock to generate the higher voltages for programming the flash. And that a "High Voltage Programmer" provides the required voltage.
 
@DavidKessner The default programming mechanism used with AVRs uses the same voltages as the MCU's specified Vcc, and does not feed a clock - it basically does a serial programming (SPI essentially), not a clocked JTAG method.
well, it feeds a clock, but a serial clock, not the MCU clock.
 
2:50 PM
The programmer linked to by the OP can generate a high voltage.
 
@DavidKessner The HV programmer allows overriding of fusebits etc. Never having used or owned a HVprogrammer, I don't know details.
 
Does anyone think this last edit goes a bit far and makes too many assumptions:
 
@DavidKessner Oh good. Then the answer is merely ill-worded, rather than incorrect. The correct answer would be to the effect that the OP needs to override fusebits using the HV programming mode, then reprogram. However, since I don't know the HV stuff well (@jippie does I think) I won't jump in there.
 
@PeterJ Pcode is wrong.
 
2:53 PM
@PeterJ No, I don't. The OP actually put that stuff in an answer (which might have gotten deleted by now). For whatever reason the OP didn't know or couldn't edit the Q directly.
@PeterJ Yeah, it doesn't run on a 555. :)
 
@DavidKessner ROTFL
I'm sure OP meant "do something like this" :-)
as opposed to "run this code on the new 555 microcontroller that is yet to be released".
 
And "led_on()" should be something more like "led_blink_once()"
I just edited the Q to be "more 555 compatible".
 
LOL you will invoke the wrath of the 555-haters.
 
@AnindoGhosh Hey, I'm the President of that club!
 
Not sure if 10mS would be too visible either ;-)
 
2:59 PM
@DavidKessner False. Insufficient facial hair to qualify.
@PeterJ 10 ms double flash is visible, and is actually more noticeable than a single 20 ms blink. I use that kind of double-flash for status indication on some designs - saves power while being difficult to ignore.
 
@PeterJ Right. Needs to be more like 200 ms.
@AnindoGhosh But a TV has a 30-ish ms refresh rate and we don't perceive the blink between frames (very much).
 
@DavidKessner Wait, let me check some code I use often.
 
Maybe 100 ms. But not 10 ms.
 
Actually didn't scroll down the bottom and noticed the OP had provided that 'code' himself that Camil had just pasted in.
 
@DavidKessner verified - 10 ms on, 50 ms off, 10 ms on, 1 second off is my standard flash routine. It works. For distinguising the two flashes well, 75 ms gap between is enough.
 
3:08 PM
@AnindoGhosh I'm confused. So you have a 50 ms "dark time" between flashes?
 
@DavidKessner Yes, that's actually more noticeable to the eye than a straight 20 ms flash, while taking (approx) the same power.
Something to do with the physiology of vision - the eye notices change of intensity more than light alone, and a double-strobe is noticed more than a single strobe.
My 10-50-10 was based off an academic paper related to vision I had read somewhere... However, I personally notice a double-strobe with 60 to 70 ms dark time better than one with just 50 ms. Over 70, the impact is steady. This is based on some experiments I just did.
 
@AnindoGhosh I can understand a 50 ms dark time (still seems short, but doable), but the OP wants 10 ms where the LED is dark between blinks. I don't think that our vision system can see that as two distinct blinks.
 
@DavidKessner It cannot. Even at 50 ms dark time, it's not as though we can consciously distinguish the two blinks (I asked my wife to count the blinks). But yes, the double flash seems brighter than a single 20 ms blink.
 
@AnindoGhosh Ok, I get what you are saying. Sometime I'll have to experiment with that.
 
Anyway I'd better head off, I look forward tomorrow to reading the 555 / Arduino / Raspberry PI / AVR / PIC / ARM solutions propsed :)
 
3:14 PM
@PeterJ Bye.
 
@DavidKessner Have any MCU board handy? It's a really neat thing to experiment with. When I use 5 flashes in a row with 50 mS dark times, the effect is inexplicably irritating. That's what I've been using for error condition indications.
@PeterJ Bye!
 
@AnindoGhosh I have an MCU board. I just don't have time to play with it. :(
 
@DavidKessner There was this software jippie had mentioned - allows scripting to be run from the computer straight through to some MCU board. I can't remember what software and which board, but I remember downloading and installing it, playing with it and then deleting it. Very useful for quick experiments like this. No flashing of MCU needed on each experiment.
@DavidKessner Or get an Arduino! :-D :-D :-D Speaking of which, why did I not do this test on the duino? would have taken me half the time setting it up.
 
@AnindoGhosh These days it would be quicker for me to write up some VHDL code to blink an LED on an FPGA.
 
@DavidKessner I'm an FPGA challenged person. I'm sure that can be cured the day I get hold of an inexpensive FPGA board to experiment with, but until then, I don't speak FPGAese
@DavidKessner Can you imagine how much mark-up the most basic FPGA experimenter boards sell for in India? 500% and up!
 
3:21 PM
@AnindoGhosh Since I got some for free, that means that for you it would be free, times 5, carry the one... Um, Free! :)
 
@DavidKessner I'm in the wrong country, and perhaps I need to be in a suitably big company as well ;-)
 
@AnindoGhosh You said it, not me!
 
Which doesn't prevent me from happily accepting donated electronics of any description.
 
@AnindoGhosh I dont mind sending electronics, the worry I always have is export restrictions and such, I have no idea how to tell what I can send over.
 
@DavidKessner Math error. 500% mark-up is 6 times free, not 5 times free.
 
3:24 PM
@AnindoGhosh I actually have been donating all of my unused samples to a local "Hackerspace". Which is like a club that builds stuff for fun.
@AnindoGhosh In India, maybe. In the US, it is only 5x. In Canada it is more like 5.342x. :)
 
@Kortuk Anything that isn't munitions by definition can be exported... or anything that can go into surface postal mail.
@DavidKessner The Canada numbers came with some sage advice, eh?
 
@AnindoGhosh I have had accellerometers and such before that I know I could not legally export, but only from reading on sites the notice of the export restriction, the product itself had nothing to warn me.
Certain electronics are a big deal for that.
 
@AnindoGhosh There are some things that are restricted from export from the US. They don't want us exporting things that could be made into weapons-- and that includes some sensors, processors, etc.
 
Yeah, what @DavidKessner is saying there. I dont know how to tell what falls into that.
 
@DavidKessner BTW we have a Mumbai HackerSpace, and it isn't really doing well, due to lack of infrastructure and dedicated space. I am a member, but not very happy with it.
@DavidKessner Yes, those fall into the FTC munitions definition.
Not sure if it is FTC, hold on.
OK, it is the "U. S. Bureau of Industry and Security" that enforces the restrictions, and apparently exporting the graphics accelerator card that is running on my PC, is illegal too. Anything with more than 4 processing cores, anything which can be used in space, and so on.
So my Intel i7 CPU is illegal too. This is amusing.
@Kortuk @DavidKessner Here you go: The official document: U. S. Bureau of Industry and Security
Oh, it doesn't auto-expand PDF? Terrible!
 
3:33 PM
@AnindoGhosh The export versions of the i7 are really just 1 GHz 4-core PIC's. Shhh, don't tell anyone.
 
@DavidKessner Shhhhhh! Cat, bag, etc.
 
But really, the i7 and your GPU were probably made in Asia and never came into the US.
 
I am beginning to suspect that... A bunch of the product types mentioned in the document are manufactured in China by the respective companies. So it's fine for the US to import them from China but not for them to then leave the US, though they can just as well get to India direct from China? Ostrich/sand/head.
 
hEElo EEverybody
 
Even better, I suspect there are items which cannot be exported to India from the US, but are available here via eBay direct from Schenzen China.
Heya @rawbrawb! Long time no chat, you're always gone when I'm around. :-)
 
3:37 PM
@AnindoGhosh I wonder why? ;)
been v busy
 
@rawbrawb Must be my taste in fashion, or something. Can't be my obvious linguistic superiority.
@rawbrawb Is that good or bad?
 
@AnindoGhosh hopefully good.
 
WOW! Microprocessors operating above 40 MHz are considered illegal for export.
 
@AnindoGhosh you know there is a difference between typing and speaking right?
 
@rawbrawb Excellent!
 
3:41 PM
;)
 
@rawbrawb Oh yes I do. If I were speaking you would need an interpreter. ;-)
 
You're discussing ITAR and USML stuff. THat is the state dept.
 
U. S. Bureau of Industry and Security
http://www.bis.doc.gov/policiesandregulations/ear/ccl3.pdf
 
@AnindoGhosh On the plus side, I now have a shopping list for when I create a new Government.
 
@DavidKessner Hahahahaha
Hmm, so we cannot own HDTV in this country, since the US disallows export of high speed DSPs.
I think it's a good thing we just buy stuff made in the far east.
No 16-bit ADC or DAC with greater than 20 MSPS. Hmm, so a resistive ladder DAC is illegal. That makes resistors restricted too ;-)
 
3:47 PM
@AnindoGhosh Darn, I can ship you the "Anisotropic plasma dry etching equipment" that I just happen to have lying around, unused.
 
Wait, my oscilloscope does better than 20 MSPS. That's illegal too.
@DavidKessner If I had any clue what that is, I might have been perturbed.
 
@AnindoGhosh I think it is used in the production of American "cheese".
 
@DavidKessner Is that like American beer? I'll pass.
 
@AnindoGhosh pun intended?
 
@AnindoGhosh hahaha
 
3:50 PM
@rawbrawb nasty
 
But I have, on occasion, bought stuff that had a card inside the box warning me that the stuff could not be taken to other countries.
 
haha
 
Ooooh, this is brilliant reading. Any optoelectronics containing "One or more than one internal “laser” diode;"... That nixes the laser mouse I have.
Okay, @DavidKessner You can send me your freebie FPGAs. The restriction reads:
‘Field programmable logic devices’ having
any of the following:
a.7.a. A maximum number of digital
input/outputs greater than 200; or
a.7.b. A system gate count of greater than
230,000;
 
@AnindoGhosh ITAR is far far more silly than those examples. Because we are multi-national, multi-jurisdictional when we deal with certain customers, they can't tell us the spec that they need because to do so would violate ITAR, because that spec may leak back out of the US.
 
@rawbrawb I'm just running a mental inventory of how many commonplace things in my house are not export-permitted. It's educational. Also, a surprising number of those things are patented by non-US companies.
 
3:55 PM
So bringing in a device that is made out side of the US is even hard even though it out performs the existing eqt. because they can't confirm if you do out perform.
 
"You could have invented it, you could be manufacturing it, but we decide who can get it".
@rawbrawb That is awesome. I'm not sure whether it is funny or just sad.
 
And a LOT of devices now do out perform. There is a bill trying to be pushed through that loosens off the restrictions because for the most part, it restricts the US's competitiveness.
 
@rawbrawb I can understand that. At the simplest level, I cannot legally import most Tektronix scopes, but I can get their far east equivalents, or better.
 
@AnindoGhosh how about "You did invent it, you are manufacturing it, but we decide who you can even talk to about it".
 
@rawbrawb If you can talk to it, will it respond?
 
3:58 PM
@AnindoGhosh oops , I said too much.
 
LOL
My secret power ;-)
 
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