Haven't tried one yet but you can get a "Y" cable off eBay that lets you hook up the tablet charger to power the tablet and the attached device. -----Original Message----- >From: Chris Roper >Sent: Apr 15, 2013 5:13 PM >To: "Microcontroller discussion list - Public." >Subject: Re: [PIC] Use of Tablet for microcontroller GUI > >@Mohit > >Sorry for the delay, I have not been reading the list over the weekend. >Here is the info that I posted in another thread about USB-OTG and the >Nexus 7, it shuold work with any modern Android device. > >OTG is On the GO, I have no idea why it is called OTG. Basically it is a >USB port that can automatically toggle between being a Host or Client. I >first found out about it with the PIC32's and haven't done much >research, perhaps others on the list can educate us both. > >In a nut shell any MicroUSB connector can be used with USB-OTG. They diffe= r >from the normal A and B style connectors in that they have 5 pins rather >than 4. >This image shows the connections (also attached as *USBOTG.jpg* for those >who have text only email) >[image: The difference - circuit] >I striped the Shroud off a MicroUSB and used a USB A Female salvaged from >a dead 4 port switch. I mounted the USB A on a small piece of Strip board >and attached the bare Micro USB plug directly to it. The whole Assembly is >then covered in Heat Shrink. > >You need a recent version of Android, so update your device to the latest. >It should detect the adapter and automatically accept any USB device you >connect to it. > >in a nut shell, an OTG capable device can be a Client or a Host, in this >case the Android Device becomes a Host. Their is a down side, there always >is, in that a Host has to supply power to the Slaves and the Host can't >draw Power from the USB connector. In other words, your Tablets Battery is >going to get hammered. To get around that I use a small 8 Port Powered HUB >from Manhattan. It can't charge the Tablet, but at least the Slaves are >not drawing Power from the Battery. > >As for devices, it should take any device that conforms to the USB >Standard. I mainly use it with a Mouse and Keyboard, both are >just recognized and used by Android, you even get a mouse pointer on the >screen so its a visual indication that OTG is working. It should also >accept any game Controller from M$ or Sony but the game must also be able >to recognize it, not all do. > >It recognizes and reads USB Flash Drives and External USB hard drives, but >on an unrooted Android device they are read only. That is sufficient for >my needs so I have not bothered to Root mine. I may do it when it is out >of warranty but that is another story. > >It also works fine with FTDI serial cables or adapter boards and I have >happily powered a PIC Prototype Directly from the Tablet whilst talking to >the Chips USART via an FTDI Chip, no drivers needed, it just worked. > >There are probably many other things you can do with it such as USB Audio, >but I have not experimented with that so far. > >Apart from the battery Life issue it, really does make my Tablet a viable >alternative to a NetBook computer and I would go so far as to say it beats >my wife's Laptop when we are traveling. > >Hope that helps, >Cheers > > > >On 15 April 2013 16:43, Harold Hallikainen wrote: > >> I've found that both Ethernet and Wi-Fi modules with a built-in stack ar= e >> a pain to work with. They lack the flexibility to do what you really wan= t. >> So, I've always ended up back with the Microchip ECN chips for Ethernet.= I >> have a back-burner project that will use the Microchip Wi-Fi module, whi= ch >> uses the Microchip TCP/IP stack running on the PIC. >> >> I think it should be possible to also do this with a BlueTooth module, b= ut >> I have never tried. I sometimes run my wife's Mac laptop through the >> BlueTooth on my cellphone to get Internet connectivity when away from >> home. But, again, I've never tried to implement this on my own. >> >> As for what Microchip chips to use, I don't think you can run the stack = on >> a PIC16. I've run it on a PIC18F6722, a PIC24HJ256GP610, and on a couple >> PIC32 chips. >> >> My Wi-Fi project is "back burner" right now, so I am not devoting much >> time to it. But one thought to ease the user interface is to have the >> Wi-Fi show up as an ad hoc network with an appropriate SSID to make it >> easy to identify from a tablet or laptop. I'd also run a DNS server on t= he >> PIC to create the "Starbucks effect" where any domain lookup returns the >> IP address of this device. So, a user connects to the device over Wi-Fi >> using an easily recognized name, then opens a web browser. As long as >> their home page has a domain name lookup (like http://www.google.com) an= d >> not an IP address or a local file (like bookmarks), they'll see the >> device. This avoids having the user key in IP addresses. Just open the >> browser, and you're there. >> >> Good luck! >> >> Harold >> >> >> -- >> FCC Rules Updated Daily at http://www.hallikainen.com - Advertising >> opportunities available! >> Not sent from an iPhone. >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .