I have a hunch that swapping 5V and 3.3V rails is going to upset a lot of people who have already built mating boards for the IOIO-OTG foortprint, so I consider this a rather major change. Whether or not there's enough board space to add additional pins near 45/46 and to route GND and 5V there is a good question. I don't currently have any concrete plans to do another board rev. If I ever do, I will see whether I can add this feature. I agree that it might sometimes be useful and is generally harmless if it is only an additive change.
On Sun, Dec 6, 2015 at 3:45 AM, <[email protected]> wrote: > Thanks for comments, Ytai ! > I understand your point in servo connection, but would it be possible to > make a slight modification, that does not increase the size of the board: > if the 3 pin rows of 3 and 5V are switched, and pin 45 is moved "up" to > second row, it could be possible to connect easily 2 servos to 45,46 pins ! > Of course this assumes that 5V can tolerate 2 servos. > > tiistai 1. joulukuuta 2015 19.49.10 UTC+2 Ytai kirjoitti: >> >> Thanks for the feedback, I agree with most of it, see inline. >> >> On Tue, Dec 1, 2015 at 2:22 AM, <[email protected]> wrote: >> >>> If I manage to desolve one of those components, is the IOIO board still >>> functional, when powered (5V) using 5V pin ? >>> For me, powering the IOIO and servos has been the biggest problem. >>> The main requirements are: >>> - IOIO could be powered using the standard 12V power adapter for "fixed" >>> projects >>> >> >> Yes, this is possible. Up to 15V is supported. Due to a bug you're >> already aware of the recommendation has been not to exceed 10V, but this >> bug is believed to have been fixed and the new units are shipping soon from >> SparkFun and SeeedStudio. >> >> >>> - in "mobile" projects, using either Lipo (7.4V) or LifePo(6.6V) battery >>> >> >> Yes, this is possible. >> >> >>> - it should be possible to SAFELY connect 3-4 servos to 5V connector in >>> IOIO and run these servos concurrently. May be a place for an appropriate >>> fuse should be added to limit the current and not damage the IOIO >>> >> >> The "3-4 servos" requirement is arbitrary. The next person is going to >> require 8 servos, and you see where it goes... The IOIO have a 3A >> regulator, which seemed to be a good trade-off between utility, cost and >> board space. Whatever load fits in this budget, great! Whatever doesn't, >> you can always use an external regulator. It is quite possible that you can >> use 4 standard size servos within 3A. This would depend on the actual >> servos, their gear ratio and the load. In either case, I agree that a >> current overload should not permanently damage the board. This is believed >> to be addressed by the new revision. One thing to ensure is that your >> motors do not badly surge the voltage as result of sudden changes in >> current. In case they do, proper protection is your responsibility (e.g. >> large capacitors and shottky diodes). >> >> >>> - another nice to have feature (even the physical size of IOIO board >>> must be increased): in P-pins where PWM is possible, there could be ground >>> and 5V pins, so that I can solve 3-pin male connector and connect the >>> standard servo 3-pin female connector. This would make it easier to connect >>> servos. >>> >> >> People have done that with "shields" etc. I don't see as servos being >> special in any way and the trade-off would be increasing board size and >> cost, which might have the next person complain about why the board is >> bigger than necessary while they don't actually use it to drive servos. I >> tried to keep the IOIO focused on being generic, with the assumption that >> for application specific requirements, people can always implement shields >> / mother-boards or spin their own version of the board, while using the >> same software stack. >> >> >>> >>> When will the new hardware revision available? >>> >> >> I cannot speak for the manufacturers. They might be waiting to finish >> existing stocks before selling the new revision, etc. At least from my end, >> I have gone through sufficient testing of the new revision from both main >> manufacturers and am pleased with it. I know for certain that both are not >> going to manufacture more of the old boards, so it is only a question of >> when the next batch comes out. >> >> >>> Can you consider these modifications, Ytai ? >>> >> >> I believe the new revision would meet most of your requirements as-is, >> except for the servo-specific features, which I disagree with. Hope you >> understand my reasoning. >> >> >>> >>> >>> >>> >>> perjantai 13. marraskuuta 2015 22.36.54 UTC+2 Ytai kirjoitti: >>>> >>>> The switcher is the small square IC next to the power connector, which >>>> has no legs. The inductor is the large-ish cylindrical component next to >>>> it. >>>> A new hardware revision of the IOIO will roll out very soon, which >>>> addresses this issue. Until then, the advice is to not power the IOIO with >>>> more than 10V. >>>> >>>> On Fri, Nov 13, 2015 at 9:25 AM, <[email protected]> wrote: >>>> >>>>> I have exactly the same problem in 2 of my IOIO boards. If it is >>>>> powered using VIN->not working. If 5-5.5v supply is connected to 5v pin. >>>>> The power led will be on, but not working, and the processor gets hot. The >>>>> resistance between GND and 5V is nearly 0 (compared to functioning board >>>>> 1-2 MOhm). >>>>> So what is the switcher to be eliminated to rescue the board ? The >>>>> micro switch near USB connector ? >>>>> >>>>> perjantai 13. marraskuuta 2015 9.28.17 UTC+2 Ytai kirjoitti: >>>>>> >>>>>> It does sound like a fried switcher, causing a low impedance path >>>>>> between 5V and ground. This is likely causing your 5V rail to sag, so it >>>>>> might explain why your Android won't connect. One way to hack around this >>>>>> problem is to desolder the switcher or the inductor. I would first verify >>>>>> this guess by measuring resistance between 5V and GND when not powered, >>>>>> and >>>>>> expect that you'll see a low value in the few ohm or less range. >>>>>> >>>>>> On Thu, Nov 12, 2015 at 2:57 PM, Zvonimir Udovičić < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> >>>>>>> >>>>>>> Dana četvrtak, 12. studenoga 2015. u 17:50:08 UTC+1, korisnik Tyler >>>>>>> napisao je: >>>>>>>> >>>>>>>> Okay, can you give us more detail? When you power the IOIO, are any >>>>>>>> of the lights coming on? How are you powering the IOIO, specifically, >>>>>>>> where >>>>>>>> are you applying the 5v? Finally, does any part of the IOIO board feel >>>>>>>> very >>>>>>>> hot? >>>>>>>> >>>>>>>> >>>>>>>> power lamp lights normally, i am powering ioio with 5V adapter on >>>>>>> 5V pin, ioio board feels hot and vin pin is not working >>>>>>> >>>>>>> -- >>>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "ioio-users" group. >>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>> send an email to [email protected]. >>>>>>> To post to this group, send email to [email protected]. >>>>>>> Visit this group at http://groups.google.com/group/ioio-users. >>>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>>> >>>>>> >>>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "ioio-users" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>>> To post to this group, send email to [email protected]. >>>>> Visit this group at http://groups.google.com/group/ioio-users. >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> >>>> -- >>> You received this message because you are subscribed to the Google >>> Groups "ioio-users" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at http://groups.google.com/group/ioio-users. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- > You received this message because you are subscribed to the Google Groups > "ioio-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/ioio-users. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "ioio-users" group. 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