I have a device that provides a constant stream of output data through a serial port. I want to use this data and display it usefully in an app. I am open to both Bluetooth or WiFi connections. I'd rather use bluetooth but from what I have read so far bluetooth is a non-starter without the MFI program so my focus is mostly on a wifi connection. I haven't worked with any serial I/O in any apps before.
This product caught my eye as a simple solution for the transmission. Will this product serve the purpose I'm looking to use it for? Is there a better option that I have?
http://www.usconverters.com/index.php?main_page=product_info&products_id=404
I have very limited ios development experience and programming in general, I'm probably a little over my head here but anxious to move forward with the project. I appreciate any helpful information.
Related
I have an external device that we manufacture that basically monitors 4 voltages, converts them to a 16 bit digital number then streams this info back to a PC every 100mS or so, using a serial over USB style chip. Basically a data logging system.
We would now like to collect this information on an iPhone and I am wondering what is the best way to get the data into the iPhone?
I am assuming there is no way we can physically connect directly to the iPhone dock connector as the protocol to do this is not available to iOS developers?
Obviously we could do it over a WiFi network but there will not always be one and we want to keep the external hardware fairly simple, i.e. no need for a computer or Wireless router etc.
If we add Bluetooth connectivity to our hardware would this work? I read that only 'Made for iPod' type Bluetooth devices will connect, in which case how can we achieve 'made for iPod' status? It would be relatively easy to add the necessary Bluetooth chips to get the system up and running.
In an ideal world we would like to do this without having to use a 3rd party interface.
I have been thinking about trying to digitise data as an audio signal – like a modem, and send it into the line input jack, but I don’t think it will be fast enough – this would be new territory for me.
Anyway all suggestions gratefully received!
Thanks!
I'm developing an iPhone/iPad app that requires it communicate with another device. I'm actually more interested in receiving input from another device that the iPhone is connected to through USB. The solution needs to work with any iOS device and cannot require it to be jailbroken.
I've heard of apps that communicate with a piece of hardware that can be plugged to the iOS' serial connection, which is similar to what I'm going to develop except that the other device I'll be connecting to is a standalone music keyboard.
best regards,
fbr
If you are developing accessories that need to connect to iOS devices and want to use your own communication mechanism then you need to join the Apple MFi program.
Several options:
Forget MFi unless you have 1000s of $ backing up your product development. Apple won't even talk to you. I've tried.
Take a look at the Serial Cable from Redpark (http://redpark.com/c2db9.html)
I've got one of those and it's ideal for apps that you can deliver on your own, but you might also be able to get them into the App Store.
Another option is to use Wifi with a Wifi-to-Serial adapter on the other end. I've used the RN-174 and RN-134 from Roving Networks successfully.
However, these solutions only get you Serial connections, but can be quite fast, especially with the RN modules. There are also Serial-to-USB converters you can use on the device's end, but that would require the device to work as a USB host, usually. If you have a USB device that wants to act as a client, these common adapters won't do the trick.
So, unless you can actually afford the MFi program, and if you really need USB connectivity, you'll have to let someone create a small box containing a USB host adapter with a Wifi chip. I don't know of a ready-made solution for this yet, although I've seen quite a few area where people would like to have such a unit.
I'm looking to connect my iPhone to an RS-232 serial device via Bluetooth. Has anyone implemented this successfully and can offer advice on hardware to use? It's kind of tricky because of the need for the Apple Authentication Processor with the device. The best potential device I've found is this guy but it only comes in an embedded package, its serial port interface is just logic-level UART rather than line-level RS-232, and I can't find a supplier with it in stock.
Any thoughts would be appreciated.
I'm considering just using WiFi to serial instead, but please ignore that possibility for the purposes of this question.
most of the question was answered by yourself already.
Basically you have 5 (+2) choices.
Join the MFi program. This might be hard to impossible if you are not part of a at least mid-size company.
Buy the OEM Bluetooth Module. I'm not sure if this is even allowed by the apple policies.
Use WiFi. Keep in mind that you want to use a wifi chipset that can act as at least ad-hoc access point. Those chipsets are quite expensive, and you have to think of a way to join existing networks (customers don't want to leave their home network to use your product). This will add a lot of cost to the BOM of your device.
Jailbreak might be an option. I never tried to use accessories with a jailbreak, so I don't know if it's possible to use bluetooth without authentication.
Work with a company that is member of the MFi program.
(Maybe an option, and depending of the speed you want to have via RS232: Eventually you can convert the audio output of the head-phone jack to RS232 levels and vice versa)
(Not really an option: develop for Android and do whatever you want)
If you jailbreak your device, you can use BTstack.org (disclaimer: I'm the author of BTstack) to connect to a Bluetooth device that supports the Serial Port Profile. You can get Bluetooth Modules that implement SPP and provide UART level output. As David R. above points out, you then need a UART to RS232 converter, e.g. the MAX232.
Ok. Another option. There are one or two companies that sell RS232 cables for iOS, eg. Skywire here: http://www.southernstars.com/products/skywire/index.html
Then, you could uses a Bluetooth RS232 extender, which consists of a RS232-to-SPP and a SPP-to-RS232 pair. Ugly, but within Apple's rules.
Well. It seems like my answer could be something you didnt ask for.
But the guy you referred to is the answer. Buy his product and you are good to go, all you need is a MAX232 chip. Converts logic level UART to RS232.
the diffrence high + voltage low zero voltage is converted to high +~10volts low -~10volts.
I use the MAX232 chip with my microprocessor, that uses logic level USART to communicate over RS232.
There is a lot of tutorials out there explaining how to hook things up.
This product works: https://serialio.com/product/bluetooth-serial-adapter/bluesnap-smart-bluetooth-40-ble-rs232-adapter
The only downside is that the adapter requires power.
It should be possibly I would think to create something in the middle that accept the bluetooth commands and convert them to serial, similar to what this does with TCP connections: https://www.npmjs.com/package/stellar-socks
My iPhone connects over adhoc wifi to a wifi sensor module.
The challenge is to code an app that uses this sensor module. But I'm not sure what specific API's to use to best architect this implementation.
I've started looking into the CocoaAsyncSocket class as it seems to be an appropriate tool for such use.
Does the user always have to manually connect to the adhoc wifi device? (through the Settings app) or can my own app handle the searching, making, and breaking of the wifi connection?
I doubt iOS lets me programmatically toggle whether Wifi is on/off.
Once the sensor data is being received, what container would best handle the stream?
For example, on other platforms, I coded a rotating queue buffer.
Thanks for your input.
Edit: The protocol in question is straight CSV formatted ASCII. Not HTTP, FTP, etc. Just raw data. The app is to simply open a port on the connected IP, and read/write.
Your application cannot turn wifi on/off, or select a wifi network.
Without more information on what protocols this wifi sensor module speaks, it will be impossible for anyone to give more than vague recommendations. If the module can serve data over an http connection, that would probably be ideal. If it requires your software to open a connection on a specific port and communicate over something other than http or ftp, your job will be a bit more complicated. CFNetwork and projects derived from it's usage, such as CocoaAsyncSocket which you mentioned. You can see another implementation of an HTTP connection over CFNetwork in ASIHTTPRequest, that may help as a reference for handling download streams, queuing operations, etc.
As for storing the data, again it's hard to give any concrete recommendations without more information. If you want to store the data to the filesystem of the iOS device, NSData will probably meet your needs. If you need/prefer to use a queue for buffering data, there is a simple category on NSArray which provides queue semantics. The link to CHCircularBuffer in that SO article is dead, but this github project appears to have it.
edit: Here is the official version of the CHDataStructures. I don't know if it's an improvement over the previous link, but it appears to be updated for the more recent iOS SDK.
Add the SSID of your wifi ad hoc networks in settings. When you see the SSID of the network, click the arrow and choose connect automatically. After this, the phone will automatically connect whenever it comes in range. After this, the two devices can communicate using regular socket APIs.
What is the best way to realize wireless communication between an embedded system (based on an AVR controller) and the iPhone? I think there are only two options: either WiFi or BlueTooth. The range is not really a problem, since both devices should stay in the same room.
I have no idea, if there are any useful WiFi boards that can be connected to an AVR based microcontroller system (or any small microcontroller), any hints would be highly welcome.
I guess the better solution would be BlueTooth, but there is also the problem: which BlueTooth board is best suited for attachment to an AVR system, and is it possible to use the iPhone BlueTooth stack for (serial) communication over BlueTooth with the AVR device.
I hope that somebody already realized such a system and can give some helpful tips...
You can get modules for both WiFi and Bluetooth that will connect to an embedded system through a UART interface, however a WiFi module will have far more processing power than your AVR microcontroller, often with spare capacity and I/O to execute additional user code, so connecting one to an AVR maybe somewhat redundant in many cases.
Bluetooth modules are simpler, less expensive, and the data-rate is better matched to the AVR's capabilities. For example these Parani modules. I have used them between an embedded system and a Laptop PC's Bluetooth, so given appropriate communications software, there is no technical reason why it could not be used with an iPhone I think. However this may be the flaw, on the PC the device was recognised as a virtual serial port, I don't know whether iPhone supports 'legacy' communications in quite the same way.
For comparison, a WiFi solution
From what I know, BlueTooth is very limited on the iPhone: There is only very few BlueTooth-Profiles implemented, and - even if they can be extended with a jailbroken iPhone - I doubt this is easy to use from the application layer.
On the other side, transferring via WiFi requires a lot of processing power and memory since much more things have to be implemented before you can even start transferring data: 802.11, cdma/ca, arp, tcp. That's a big task.
Is it an option to build a hardware extension to the iPhone ? You might be able to get the serial connection and power out of the dock connector. Then even ZigBee could be very helpful.
Here's an article you might find helpful. I would lean toward a WiFi solution just because of the added flexibility available.
http://www.embedded.com/design/networking/215801088
-t
Some of the other people at the office have done AVR <- Bluetooth -> Symbian and AVR <- Bluetooth -> PC solutions without trouble. There is lots of info, reference designs and source available. I have no idea of how hard it would be to use Bluetooth on Iphone.
The exact module is probability also not important as long as it got some type of serial interface (I2C,SPI) to interface to the AVR and some source code show how to use the module.
Is it an 8-bit or 32-bit AVR? For the AVR32 processors there's support
for WiFi in the Atmel 1.5.0 Software Framework using SD-card-mounted
WiFi modules from HD Wireless (http://www.hd-wireless.se), including
an IP stack (lwIP). Be aware that you need Ad-Hoc (IBSS) support to
connect directly to the iPhone.
There is WiSnap kit. It can connect directly to a standard RS232 interface or through the TTL UART interface to embedded processors. We are planning to use it in our project. It also has Ad-Hoc support.
There are some usage examples and an iPhone application for connection setup.
http://serialio.com/products/mobile/wifi/WiSnapKit1.php
What are you trying to communicate between your AVR and the Iphone? The Iphone is made for the web along with everything apple (which AVR's are decidedly not). So what works well is an embedded device that exposes a web-interface. Like the Transmission bittorrent client on Linux. Also nowadays many low-power small form-factor linux platforms exist that will allow you to do this.
For instance Gumstix has an ARM based platform that runs linux and includes WiFi (Overo Fire).