Sorry, I can't really understand what you're asking / suggesting. Which pin 40 are you talking about and what exactly do you want to do with it? I don't think the fuse can easily be destroyed. It is resettable.
On Thu, Feb 13, 2014 at 6:15 AM, fabrio pellegrinetti <[email protected]>wrote: > Thanks Ytai. > > The solution you propose is very interesting. > But is there a simpler solution? > Is there a way to intervene by software to change the state of pin 40 of > the PIC24F? > I want to change the state of pin 40 to act on the FET Q2 so as to > dynamically change the VBus. > From java programming or modification to the firmware? > Looking at the diagram IOIO-OTG, I noticed that one pin of switch_spdt is > marked with "U4", but I can not find a match. > Maybe I'll go OT: surely I've burned the fuse of ioio. > Could you tell me what this fuse on the board and its spefifiche to buy > new and replace it? > > Thank you for the wonderful device that you created Ytai > > On Tuesday, February 11, 2014 5:48:38 PM UTC+1, Ytai wrote: > >> OK, I think I understand now. I don't think you need a digital >> potentiometer for that. Look at the IOIO-OTG schematic and identify Q1. It >> is a p-Channel FET responsible for the power supply on the VBUS line. When >> the IOIO is in device mode, its gate is left floating, and thus gets pulled >> up by R3 and the FET is not conducting. >> >> When in host mode, the PIC will pull the gate low through Q2 and R3. >> According to the setting of R3, the gate voltage will vary, which can be >> used to put Q1 in linear mode, so that it acts as a resistor on VBUS and >> limits charging current. >> >> All you're missing, it being able to pull Q1's gate directly to GND in >> order to supply full current when your main supply is up. You can probably >> just extract a single wire from the leg of the chip, and connect it through >> an n-FET to GND, where the n-FET gate will be driven by a signal that tells >> you that your main supply is good. >> >> >> On Tue, Feb 11, 2014 at 2:23 AM, fabrio pellegrinetti >> <[email protected]>wrote: >> >>> Thanks for the answers. >>> >>> let me try to explain better...what I would need on the ioio is to >>> control the vbus with a digital potenziometer ioio embedded (controlled by >>> java) instead of the standard one because I need to mantain the usb >>> connection always active. >>> When the power line is present, I need to put via software the vbus at >>> the maximum value for the android recharge, while when the power line is >>> off the system needs to use the backup battery. In this case the vbus has >>> to go to the minimum in order to continue to use the usb connection. >>> >>> So, I need an hardware change on the ioio. >>> >>> >>> >>> >>> On Friday, February 7, 2014 11:09:30 PM UTC+1, Ytai wrote: >>> >>>> Such a FET already exists in the IOIO-OTG, however, this will also >>>> cause the USB connection to get dropped, which is I assume not what is >>>> desired in this case. >>>> On Feb 7, 2014 9:06 AM, "Nishant Sood" <[email protected]> wrote: >>>> >>>>> Fabrio, >>>>> >>>>> If you want to control charging of the android programmatically (in >>>>> the hardware it cuts off only when full charge automatically) then I would >>>>> suggest controlling the power going to the android controlled using a >>>>> power >>>>> mosfet switched programmatically when you sense the system has gone to >>>>> battery backup >>>>> >>>>> >>>>> On Fri, Feb 7, 2014 at 10:28 PM, Ytai Ben-Tsvi <[email protected]>wrote: >>>>> >>>>>> I don't know if there's a programmatic way to disable charging on the >>>>>> Android. >>>>>> What you *can* do, however, is detect the power fault condition and >>>>>> put the phone to sleep. It should take very little current at this mode, >>>>>> assuming the battery was previously fully charged. >>>>>> >>>>>> >>>>>> On Fri, Feb 7, 2014 at 7:49 AM, fabrio pellegrinetti < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> >>>>>>> hello to all. >>>>>>> during the development of my home automation project, I came across >>>>>>> the problem of the power supply of Android and ioio which must be >>>>>>> separated. >>>>>>> my board provide power supply of 14V 2A with a transformer 220V to >>>>>>> 14V and one backup battery of 1200mAh and 12V recharged from the >>>>>>> transformer. >>>>>>> When the the power line is off, the battery must supply power at the >>>>>>> ioio, but he mustn't to the android. >>>>>>> For now I use Y split cable power supply double USB A and one usb >>>>>>> micro. >>>>>>> >>>>>>> Micro usb connected to the android, first usb to ioio and second usb >>>>>>> to another standard android power supply. the poteziometer Vbus is >>>>>>> set to >>>>>>> minimum in accord to the usb debug survey. >>>>>>> Problem is when the system goes on battery the an amount of mA goes >>>>>>> to the standard android power supply and this reduce backup battery >>>>>>> charge >>>>>>> What I would like is to be able to check the current Vbus, from java >>>>>>> code from a ioio embedded digital potenziometer. >>>>>>> >>>>>>> so when detect power failure, I can dinamically reduce Vbus current. >>>>>>> >>>>>>> thanks >>>>>>> best regards >>>>>>> >>>>>>> fabrio >>>>>>> >>>>>>> -- >>>>>>> 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/groups/opt_out. >>>>>>> >>>>>> >>>>>> -- >>>>>> You received this message because you are subscribed to a topic in >>>>>> the Google Groups "ioio-users" group. >>>>>> To unsubscribe from this topic, visit https://groups.google.com/d/to >>>>>> pic/ioio-users/s_NY9im_SVY/unsubscribe. >>>>>> To unsubscribe from this group and all its topics, 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/groups/opt_out. >>>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> *Thanks & Regards,* >>>>> >>>>> *Nishant Sood* >>>>> *--* >>>>> *CEO and Founder* >>>>> >>>>> *Winacro Innovation's Inc.* >>>>> *----------------------------------------* >>>>> *www.winacro.com <http://www.winacro.com>* >>>>> *----------------------------------------* >>>>> *Contact's:* >>>>> *Mobile: +91-8447476798* >>>>> *Phone: 0129-4176798* >>>>> *Email: [email protected]* >>>>> >>>>> -- >>>>> 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/groups/opt_out. >>>>> >>>> -- >>> 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/groups/opt_out. >>> >> >> -- > 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/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "ioio-users" group. 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