I'm quite new to Objective-C programming and I have a problem with my app.
It connects to a device (an electronic board) through a Bluetooth Low Energy interface. My iPad is acting as a Central Manager, and the device it gets the data from acts as a Peripheral.
I use the CoreBluetooth framework.
It connects perfectly when I run the app on my iPad (iOS 7.02), but on any other device it hardly ever succeeds. I tried it in four other devices, all of them with the same iOS (7.02) and they hardly ever connect successfully to the electronic board (they managed to connect in a couple of chances).
I'm lost and don't know where to open a path to find the solution to that problem.
I don't know which other information could be useful to solve that problem.
Well there is the obvious, but worth mentioning. You bluetooth is on and you've scanned and picked up the Smart Device with your Smart Ready device. Given a yes to all of the above it just won't connect?
Have you ensured that it's not auto connecting to one of your other devices that you've previously connected with? Unless you've made some extraneous adjustments to your smart device's firmware it will only connect to one device at a time.
Related
From macOS, I'd like to detect the presence/proximity of already paired (via iCloud) Bluetooth LE devices such as a user's iPhone or Apple Watch. Is there a way to do this without running a custom-built app on the user's iPhone/Watch?
I can easily get a list of devices using CoreBluetooth, and seemingly also get RSSI signal strength from this device list, but I don't see a way to correlate the random UUID with a known device, as described in this question.
I've looked at some possible solutions including turning an iPhone into an iBeacon and the MultipeerConnectivity framework, but it looks like both of these require an app to be running on all devices (Mac, iPhone, and Watch). An example app that does not appear to require an app running on the iPhone/Watch is here.
Please note that I am working within a sandboxed environment. Thank you in advance for any suggestions.
I work with an embedded device that has a USB host port. I would like to connect an iPhone to it and communicate via USB. I have done development on this and ported the functionality to connect to usbmux on the iPhone and have successful communication, however there is another problem.
All development was done with the iPhone connected to a powered USB hub that was connected to my device, as soon as I connected it directly, after enumeration it starts to drain the battery of my embedded device and causes a tension (voltage) drop that causes my device to turn off.
I know that after enumeration usb devices can draw up to 500 mA from the usb port, but I was wondering if there was a way to limit that to 100 mA (while still having the iPhone registered).
I found various questions regarding controlling voltage on the data pins or vcc from the usb port and I understand that's not possible, I'm looking for a software solution (although hardware solutions are welcome).
tl;dr: Is there a way to supply the iPhone with less than 500 mA after enumeration? Could I do this in software? Or do I need a hardware solution? I don't want to turn the port on/off, just limit the power draw of the iPhone.
NOTE: I am using Windows CE 6.0, if it is something that can only be done by modifying the drivers, or having direct access, there is no problem.
P.S. also, if there is a way to do this in *nix (or some other open source OS) that I could look at the source code and port it to Windows CE please let me know.
When a device shares its available configurations (see USB chapter 9), it specifies how much power it requires for each configuration. The host should look at all the available configurations and choose which one it wants.
In practice, however, these things don't work so smoothly.
The last time I looked at this, Windows always chose the first configuration. MacOS always chose the lowest power configuration (or highest, I can't remember). I never looked at WinCE or Linux.
If you're writing/modifying the driver, you can set your own rules for which configuration to choose, including looking for one that's 'self powered'. The iPhone, however, might only have one descriptor that always requests 500mA, bus powered. If so, then you're pretty much screwed since there's no way to let the iPhone know it's not OK to draw power.
That being said, I believe all the iPhone accessories are actually USB host (as opposed to USB device), and given that they don't always supply power, the iPhone must be capable of enumerating self powered.
I like the answer by Russ Schultz but I want to add another one:
No.
The descriptor of the peripheral device, iPhone in this case contains bMaxPower. If you enumerate this device, you also accept the power demand. It is not possible to only supply less, lets say 300 mA, if you already enumerated the device with the 500 mA desriptor. If this is what you wanted.
If the device provides multiple configurations, you are as mentioned by Russ free to write a driver which selects the configuration with less power. Hopefully, the device will then only consume the granted power.
Many peripheral devices just don't care. Most devices only provide one configuration with 500 mA. And there are a lot of devices which just consume more than they say ...
I need to write a number of drivers for both HID USB devices as well as some old serial devices. The drivers are to pull data off the device and then send the data over to an application that then consumes it. Since the Apple Docs mention that a lot of USB and HID communication can be done from the user space I had assumed that I would not need to write a kernel extension, at least not for the HID devices. Could some one tell me a more solid way to determine this?
Thanks!
If you're writing a single application that must talk to one or more USB HID devices you may well find you can just access the devices straight from the application using the application-level USB APIs.
A kernel driver would be more for something like a networking or mass storage device that needed to integrate with the kernel to be be available to multiple applications.
This Apple document Common QA and Roadmap for USB Software Development on Mac OS X goes into some detail on the matter and links to example code too.
I want to catch commands from bluetooth peripheral in iOS.
Could anyone help me out?
There are a few ways of doing Bluetooth on iOS, and different ones have different methods:
An accessory that's part of the Made for iPhone program (see the answer to this question if you want to know what that entails)
A device that uses Bluetooth 4.0 Low Energy mode
Talking to another iPhone with GameKit
A device using one of the Bluetooth profiles Apple support natively: Hands-free profile, headset profile, A2DP, AVRCP, etc.
To answer those in order:
If you're part of the Made for iPhone program, you'll already know where to find this information, and it's not public: ask your contact at Apple for help.
If your device uses Bluetooth 4.0 Low Energy, look into the Core Bluetooth framework.
If you're trying to get two iPhones talking together, look into GameKit.
If you're working with a device that uses an Apple provided profile, you shouldn't have to do anything, it'll just work. For example, an A2DP device will stream audio played from the phone without needing programmer intervention. You can do a few things to control it: there's a Core Audio function somewhere that lets you choose whether to send audio to a Bluetooth device. If you're trying to support AVRCP, look into handling remote control events.
If your device doesn't fall into any of the above categories, you're probably out of luck and can't use it with iOS.
I'm building a small controller device that I'd like to partner with a computer. I've settled on using OSC out from my custom built hardware and am pretty satisfied with what I can get from WOscLib. Two goals I'd like to achieve are portability and a very nice ratio between battery:computing power, and this has lured me towards using iPhoneOS to accomplish my goals.
I think the iPad would suit my needs perfectly, except that using wifi to broadcast OSC out from my device requires that device to be connected to a third device with a wifi chip, and this would destroy the goal of portability, whilst also introducing potential latency and stability headaches. My question is pretty simple: Can I push OSC commands FROM my controller TO an iPad via USB and the Camera Connection Kit? If I could accomplish this, the two major goals of my project would be fulfilled very nicely.
This seems like it should be a simple little question, but researching this obsessively over the past few weeks has left me more almost more uncertain than if I had done no research at all. I'd really like some more confidence before I go down this route, and it seems like it should be possible. Any insight would be very, very appreciated.
The simple answer is that you can't :-(
In order to interface your custom hw you'll have to
obtain a license from apple.
no third device is required. you can click "create network" on your wifi menu in osx and then you ipad can connect directly to that. many apps now use osc over wifi on the ipad. some are done in java. im not sure about objective c.
You could connect a USB ethernet device to the iPad Camera Connection Kit and send OSC over ethernet from your custom controller.
Somewhere along the line since this question was asked, USB ethernet devices became officially supported over the CCK.