So, we bit our lip * On Mon, Jul 4, 2016 at 4:16 PM, William Hermans <[email protected]> wrote:
> @Gerald > > Actually, my buddy and I would have bought the white, if that's all that > was available. So, much to our surprise when the beaglebone black was > announced . . . we immediately jumped on the pre-order list for two boards > . . . > > Would we have prefered you did one thing, or another slightly differently > ? Sure ! But as it is, you saved us 50% right away, by doing what you did > with the BBB versus the BBW. So . . . we nite our lip. Then implement what > we have to on the side to make the BBB work for our own application. Too > bad many youngsters would prefer to complain about what the board *ISNT* > versus what the board *IS*. > > On Mon, Jul 4, 2016 at 4:09 PM, William Hermans <[email protected]> wrote: > >> When you design low cost hardware, you have to make certain decisions to >>> get the cost down. >>> >>> 1) As few components as possible. >>> 2) Limit the application. Only one application, >>> 3) Push as much cost outside, for example the power supply. >>> 4) Lowest cost components. >>> 5) Limit the features. >>> 6) Cut the profit. >>> >>> Yes, there are several things I could have done different. Many of these >>> no one has even identified. But if I had, you would not have bought it >>> because it cost too much. After all hardware is supposed to be cheap. That >>> is where the value is, in the price. Not the value.. >>> >>> Nobody asked how I took it from $89 to $49. They just bought them up and >>> complained that it didn't do all the things they wanted it to do for $49. >>> >>> If anyone of you want to change the design, add more features, make it >>> more robust, add more cost, increase the price, manufacture it and sell it, >>> by all means, go ahead. I am sure there will b a few folks that value the >>> hardware and recognize that value, and will pay for it. >>> >>> But, I suspect the majority will complain that it is too expensive and >>> will stay with the BBB and instead ask how to flash the latest image in the >>> BBB and why does my my GPIO does not work.. >>> >> >> Exactly, or close enough to what I was getting at. So Instead of me >> saying: "Pay no attention to John, as he tends to pontificate on others >> comments, and has no idea what the hell he is talking about." Let me just >> say that I figured Gerald had the sole purpose of designing this board to >> work "good enough" while remaining within a specified price range. e.g. it >> works, and it's cheap. >> >> On Mon, Jul 4, 2016 at 4:02 PM, Gerald Coley <[email protected]> >> wrote: >> >>> When you design low cost hardware, you have to make certain decisions to >>> get the cost down. >>> >>> 1) As few components as possible. >>> 2) Limit the application. Only one application, >>> 3) Push as much cost outside, for example the power supply. >>> 4) Lowest cost components. >>> 5) Limit the features. >>> 6) Cut the profit. >>> >>> Yes, there are several things I could have done different. Many of these >>> no one has even identified. But if I had, you would not have bought it >>> because it cost too much. After all hardware is supposed to be cheap. That >>> is where the value is, in the price. Not the value.. >>> >>> Nobody asked how I took it from $89 to $49. They just bought them up and >>> complained that it didn't do all the things they wanted it to do for $49. >>> >>> If anyone of you want to change the design, add more features, make it >>> more robust, add more cost, increase the price, manufacture it and sell it, >>> by all means, go ahead. I am sure there will b a few folks that value the >>> hardware and recognize that value, and will pay for it. >>> >>> But, I suspect the majority will complain that it is too expensive and >>> will stay with the BBB and instead ask how to flash the latest image in the >>> BBB and why does my my GPIO does not work.. >>> >>> >>> On Mon, Jul 4, 2016 at 5:46 PM, John Syne <[email protected]> wrote: >>> >>>> Harvey, you raised several very good points. I cannot say I disagree >>>> with anything you said. >>>> >>>> Regards, >>>> John >>>> >>>> >>>> >>>> >>>> > On Jul 4, 2016, at 3:36 PM, Harvey White <[email protected]> >>>> wrote: >>>> > >>>> > On Mon, 4 Jul 2016 15:13:00 -0700, you wrote: >>>> > >>>> >> Pay no attention to William. You comments are welcome and Gerald has >>>> accepted your comments as valuable input by thanking your for your >>>> feedback. Now, let me address your concerns: >>>> > >>>> > From my own engineering standpoint (and opinions will, of course, >>>> > vary): >>>> >> >>>> >> 1) The power supply used to power the BBB should be selected so that >>>> it does not damage the BBB, so a 2A power supply was specified. If you wish >>>> to change that specification, then the onus is on you to verify that a 4A >>>> power supply will not damage the BBB. Your conclusion that is may damage >>>> the BBB means that you should not use a 4A power supply. In addition, a >>>> power supply that is spec’d at 4A should not shutdown when it sees a 4A >>>> load, but rather, it should current limit at 4A. If the power supply is >>>> spec’d at 4A, then 4A should not be treated as a short circuit. >>>> > >>>> > I would have designed the power supply circuitry so that with a power >>>> > supply of appropriate minimum rating, the maximum rating would not >>>> > have mattered. Using a power supply with a maximum current rating to >>>> > avoid damaging circuitry is not (again, IMHO) the best solution. If, >>>> > because of economic considerations, that decision is made, then it is >>>> > imperative of the designer to put this information specifically in the >>>> > power supply recommendations. Not doing this leads to damage, doing >>>> > this puts the responsibility on the user. Is this a "before the >>>> > design/after the design"? I don't know, and I don't remember (either >>>> > way) if this warning was ever in the power supply requirements. >>>> > Hindsight is 20/20, of course. If it's that important, then perhaps >>>> > the documentation needs to be changed. Decision not up to me. >>>> > >>>> > >>>> >> 2) The TI spec for the TPS65217C is a general recommendation as they >>>> are unaware of how you are going to use the part. The BBB SYS_5V powers >>>> several subsystems, including HDMI, I/O (VDD_3V3B) and USB. Clearly you >>>> could move the 100uF to the other side of the TPS2051, but then you need an >>>> additional capacitor on the SYS_5V which increases the cost and doesn’t >>>> provide any clear benefit, if you choose the correct power supply. >>>> > >>>> > "correct power supply" bothers me. I'm familiar with minimum current >>>> > capacity, voltage limits, short circuit current limits (infrequently >>>> > applied). Again, "a 4 amp power supply will allow the board to damage >>>> > itself, so we depend on a 2 amp maximum supply to avoid damage." This >>>> > could be discussed a bit.... >>>> > >>>> > >>>> >> 3) As Gerald has pointed out, the BBB is just a reference design. It >>>> was designed as a low cost solution which meant that tradeoffs were >>>> required to keep the price low. Clearly things could have been done >>>> differently, but then the BBB price would have been much higher and the >>>> board larger. Given that most users would probably not need these extra >>>> features, they were not incorporated into the current design. There are >>>> several spinoffs of the BBB, some with wifi, some with more RAM, etc, but >>>> none have been as successful as the BBB. >>>> > >>>> > Hmmm, well, perhaps (although not required) it might be nice to know >>>> > what the engineering limitations are of the design. >>>> > >>>> > I've seen 1) the ones I know about, and 2) the ones I haven't found >>>> > out yet... and 3) the ones people are going to have to tell me >>>> > about... >>>> > >>>> > and I do like paranoid designs..... >>>> > >>>> > Harvey >>>> > >>>> > >>>> >> 4) While I have provided Gerald input into both the BBB and >>>> BeagleBoard-x15 designs, I ultimately defer to his judgement because he has >>>> the track record or having designed several products that are very >>>> successful. >>>> >> >>>> >> From my prospective, the BBB design is good, but your input was none >>>> the less valuable. >>>> >> >>>> >> Regards, >>>> >> John >>>> >> >>>> >> >>>> >> >>>> >> >>>> >>> On Jul 4, 2016, at 2:11 PM, William Hermans <[email protected]> >>>> wrote: >>>> >>> >>>> >>> kzsoltkzsolt, >>>> >>> >>>> >>> I would like to point out to you that you're talking to *the* >>>> person who designed the beaglebones, who also used to work for Texas >>>> Instruments at some point in his career. Someone who has made his designs >>>> free of charge to the public, which he has made perfectly clear to you in >>>> these post that you're free to change and use for your own personal use. >>>> >>> >>>> >>> So, telling him things, he probably already knows, in hopes of >>>> making yourself looks good. Actually make you look like a "know it all". >>>> e.g. it doesn't make you look good. >>>> >>> >>>> >>> SO perhaps you should realize that Gerald is probably well aware of >>>> what you're trying to discuss here, but is unwilling to change for various >>>> reasons. Reason, that you, I, or the next person do not need to understand. >>>> Because we can change to designs to our own liking if we so wish. >>>> >>> >>>> >>> On Mon, Jul 4, 2016 at 1:55 PM, Gerald Coley < >>>> [email protected] <mailto:[email protected]>> wrote: >>>> >>> Thank you for your feedback. >>>> >>> >>>> >>> Gerald >>>> >>> >>>> >>> On Mon, Jul 4, 2016 at 3:18 PM, <[email protected] <mailto: >>>> [email protected]>> wrote: >>>> >>> First of all making changes on design "tomorrow" is irresponsible, >>>> so I never request it. But good to know where is some "leak" in design. For >>>> example it is help to make workaround. >>>> >>> >>>> >>> "TI did not write that specification" >>>> >>> No, but use it in all reference design. See TI TPS20x1 PDS >>>> application information. See for example TPS2051 docu Fig 33. >>>> >>> >>>> >>> "If you put the CAP after the switch then ..." >>>> >>> Then why CAP placed OUT of PDS in all TI application information? >>>> >>> Because PDS has soft start feature which prevent overload IN (BBB >>>> SYS power rail). See for example TPS2051 docu Fig 4 and 8. >>>> >>> Fig 8 is perfect draw for this. The soft start feature limit charge >>>> of 100uF to 0,5A, therefore current never exceed USB1 and 2 current limit, >>>> therefore no dip on IN. >>>> >>> This is one main function of PDS. >>>> >>> >>>> >>> "I did not design the board for your application" >>>> >>> It is not required. But during research work to specify our problem >>>> I found many topic where users discover mysterious problems with power >>>> supply, and try to found a right one for BBB. This can be originated from >>>> startup current peak. >>>> >>> >>>> >>> >>>> >>> -- >>>> >>> For more options, visit http://beagleboard.org/discuss < >>>> http://beagleboard.org/discuss> >>>> >>> --- >>>> >>> You received this message because you are subscribed to the Google >>>> Groups "BeagleBoard" group. >>>> >>> To unsubscribe from this group and stop receiving emails from it, >>>> send an email to [email protected]<mailto: >>>> [email protected]>. >>>> >>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/beagleboard/b974f98a-0cff-4380-af1f-9ce5db9e199f%40googlegroups.com >>>> < >>>> https://groups.google.com/d/msgid/beagleboard/b974f98a-0cff-4380-af1f-9ce5db9e199f%40googlegroups.com?utm_medium=email&utm_source=footer >>>> >. >>>> >>> >>>> >>> For more options, visit https://groups.google.com/d/optout < >>>> https://groups.google.com/d/optout>. >>>> >>> >>>> >>> >>>> >>> >>>> >>> -- >>>> >>> Gerald >>>> >>> >>>> >>> [email protected] <mailto:[email protected]> >>>> >>> http://beagleboard.org/ <http://beagleboard.org/> >>>> >>> [email protected] <mailto:[email protected]> >>>> >>> >>>> >>> >>>> >>> -- >>>> >>> For more options, visit http://beagleboard.org/discuss < >>>> http://beagleboard.org/discuss> >>>> >>> --- >>>> >>> You received this message because you are subscribed to the Google >>>> Groups "BeagleBoard" group. >>>> >>> To unsubscribe from this group and stop receiving emails from it, >>>> send an email to [email protected]<mailto: >>>> [email protected]>. >>>> >>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/beagleboard/CAHK_S%2BcAH_U%3DVtJmLq62wrVPmRg8%2Bn27YjWM_oeorZezSTKorQ%40mail.gmail.com >>>> < >>>> https://groups.google.com/d/msgid/beagleboard/CAHK_S%2BcAH_U%3DVtJmLq62wrVPmRg8%2Bn27YjWM_oeorZezSTKorQ%40mail.gmail.com?utm_medium=email&utm_source=footer >>>> >. >>>> >>> >>>> >>> For more options, visit https://groups.google.com/d/optout < >>>> https://groups.google.com/d/optout>. >>>> >>> >>>> >>> >>>> >>> -- >>>> >>> For more options, visit http://beagleboard.org/discuss < >>>> http://beagleboard.org/discuss> >>>> >>> --- >>>> >>> You received this message because you are subscribed to the Google >>>> Groups "BeagleBoard" group. >>>> >>> To unsubscribe from this group and stop receiving emails from it, >>>> send an email to [email protected]<mailto: >>>> [email protected]>. >>>> >>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/beagleboard/CALHSORo-TL2x_vUEni%2B-daiSEQXxLUU_N5p%2BEh%2Bt6tzpuuPT0g%40mail.gmail.com >>>> < >>>> https://groups.google.com/d/msgid/beagleboard/CALHSORo-TL2x_vUEni%2B-daiSEQXxLUU_N5p%2BEh%2Bt6tzpuuPT0g%40mail.gmail.com?utm_medium=email&utm_source=footer >>>> >. >>>> >>> For more options, visit https://groups.google.com/d/optout < >>>> https://groups.google.com/d/optout>. >>>> > >>>> > -- >>>> > For more options, visit http://beagleboard.org/discuss >>>> > --- >>>> > You received this message because you are subscribed to the Google >>>> Groups "BeagleBoard" group. >>>> > To unsubscribe from this group and stop receiving emails from it, >>>> send an email to [email protected]. >>>> > To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/beagleboard/cjolnb1s1bddugkd1v6c4jeqm1a0mhmvhh%404ax.com >>>> . >>>> > For more options, visit https://groups.google.com/d/optout. >>>> >>>> -- >>>> For more options, visit http://beagleboard.org/discuss >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "BeagleBoard" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/beagleboard/70E6C922-DEB1-451D-A72C-AC4C2EA2DF06%40gmail.com >>>> . >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> >>> >>> -- >>> Gerald >>> >>> [email protected] >>> http://beagleboard.org/ >>> [email protected] >>> >>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "BeagleBoard" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/beagleboard/CAHK_S%2BcSGF0gqB5yJ4EQdbYHMvS04cNOej%2B1Bw8L5y7W6AnH4A%40mail.gmail.com >>> <https://groups.google.com/d/msgid/beagleboard/CAHK_S%2BcSGF0gqB5yJ4EQdbYHMvS04cNOej%2B1Bw8L5y7W6AnH4A%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CALHSORoMZ3MGFWPsXdhmAXPy-6xFbDT1cGTsY5wTEX4NACF3iA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
