I have a project which the information from the microcontroller (drop rate changes of dextrose like sending notification "nearly empty" or "Sudden change of drop rate. Drop rate of 15 automatically return to 14") would display in an application in a computer. I am thinking of using ZigBee and it would be responsible for transferring the information but I am new with the technology.
Does anyone could help me how to program the ZigBee module? I have seen some articles saying that it could be programmed in eclipse CDT. I am bit confused how to get start.
Any help would be appreciated. Thanks!
Use USB Explorer device (or similar) to enter a serial terminal session on the receiving XBee.
Type ATMY to get the receiving XBee's address. Write it down.
Put the sender in the USB Explorer and type ATDL plus the receiver's address, like "ATDL798A728"
Type ATWR to save this setting.
Attach sender XBee's UART (TX and RX pins) to microcontroller.
Plug receiving XBee into USB Explorer attached to computer.
Run Processing sketch or similar to read from the serial port.
The two XBees will run by default in 'transparent mode,' which pipes data coming into one UART out of the other UART, exactly like a wire. So when your microcontroller writes data into the sender XBee, it will come out of the receiving XBee and be read (and displayed or whatever you need) by your software.
It really depends on how much configuration your installation can handle. Is this a one off installation, or a "system" of products you want to make that have to be able to work together in whatever configuration they're bought?
As already explained, xbee modules that have the whole radio + stack already setup and working for serial data are simple to use for the trivial case of you sending out a few pre-paired setups form the lab, or even site installation by an expert.
If your embedded devices have to find each other automatically, then you'd need a way to get the embedded microcontroller to get the modules discover each other, make a connection, and then have the application code in the embedded microcontrollers talk to each other and identify what they need to do with each other.
In this case, you probably would be better off with the (upfront much more complex and likely expensive) design where the zigbee stack is inside the embedded controller, so your application code can use it properly to control connectivity.
The TI zigbee pro evaluation kit is very comprehensive, and seems great to me so far. It sounds like you're at the point where you need to spend some money and get some experience with real modules, just to get a feel for the technology. Though be warned, you may need IAR embedded workbench to work with these long term, and that's pretty expensive software!
Alternatively, Atmel have a pretty interesting looking zigbee implementation with their "bitcloud" software platform (free zigbee pro stack!! woo! and they have a free ARM toolchain!) but I've found the getting started info around the bitcloud stuff is really lacking, and while I can get the code setup and compiling, I'm not confident to buy enough of their evaluation gear for a zigbee pro mesh network to test it in real life yet.
PS: if you're getting started with short range wireless, i can't recommend this book highly enough. http://www.amazon.com/Essentials-Short-Range-Wireless-Cambridge-Series/dp/0521760690/ref=sr_1_2?ie=UTF8&qid=1336091059&sr=8-2
It contains very good introduction to the different technologies available, and the strengths and weaknesses of all of them (and wireless in general) Plus it will leave you in a good position to start understanding the features you really need for the system you're designing.
some of the zigbee/xbee modules simply behave as wireless serial, no programming required just turn them on. Others require programming. It depends on what your needs really are. the ones that behave like wireless serial have an AT command set if I remember right so you can adjust some things, like for example if you want more than two (more than one wireless point to point connection) you can specify which two talk to each other...
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I am involved in a project where we have some kind of IoT device. An nxp processor with an LTE modem on a PCB. The software running on it connects to the modem over a single uart interface. It will initialize the modem through AT commands, and finally made a data call to the provider (PPP).
Then, it uses lwIP (light weight IP) to open some mqtt subscriptions, and allow user code to make http get/post requests to our servers.
Every 15 minutes we want to retrieve signal strength from the modem and report this back to the server. What I do now, is put the modem back in command mode, retrieve the signal strength info, go back to data mode, and resume normal operation.
The round trip from data mode, to commando mode, and back to data mode takes several seconds (4-5 ish). This is annoying, because during that time we are not receptive for commands.
I've read about gsm mux 07.10. By following some defined protocol it allows to create virtual serial ports, over one physical uart. That sounds nice, although I realize this will go at the cost of performance (bytes will be added to each frame we send to either command mode / data mode).
The gsm mux 07.10 spec dates from 1999. I am far from an expert in mobile solutions. I was wondering: is muxing still the way to go? How does a typical smart phone deals with this for example? Do they include modems with more than one uart to have parallel access to AT commands and a live internet connection? Or do they in fact still rely on gsm mux?
If somebody would be so kind to give some insights. Also on potential C libraries that are available that implement gsm mux 07.10? It seems that TinyGSM implements it (although I can't seem to find where), and I also can find the linux kernel driver that implements gsm mux 07.10. But that driver is written on top the tty interfaces in linux, so that would mean I would have to reverse engineer the kernel driver and strip out the tty stuff and replace it with my own uart implementation.
First of all, the spec numbering is the old GSM specification numbering, so those old specs will never be updated, the new specifications with new numbering scheme will. I do not remember when the switch was made, but I do remember someone at work giving a presentation on 07.10 probably around 1998/1999, so probably a few years after that or around that time (and definitely before 2009).
The newer spec numbering scheme uses three digits for the first part.
So for instance the old AT command spec 07.07 is now 27.007, and the current 07.10 multiplex specification is 27.010.
The following is what I remember of 07.10.
The motivations for developing 07.10 was to exactly support the kind of scenario that you describe. Remember back in the mid 90's, if mobile phones had a serial interface then that was RS-232 though each manufacturer's proprietary connector at the bottom of the phone. One single serial interface.
However, in order to use 07.10 mux in serial communication you needed to install some specific serial drivers in Windows with support for 07.10 (and I think maybe there was some reliability issue with them?), and for that reason 07.10 never took of and became anything more than an rarely used solution.
Also by the end of the 90's additional serial interfaces like Bluetooth and IrDA became available on many phones, and later USB as well, which both added additional physical interfaces as well as natively multiplexing within each protocol.
So the need for multiplexing over physical RS-232 became less of an issue, and whatever little popularity 07.10 ever had dwindled down to virtual nothing.
Fast forward a couple of decades and suddenly someone asks about it on stackoverflow. Good on you :) As far as I can tell I cannot see any fundamental problems with using it for the purpose you present.
Modern smart phones that support AT commands will most likely have a code base for the AT command parsing with roots in the 90's, which most likely include the AT+CMUX command. Of course manufacturers today have zero explicit wish for supporting it, but when it is already present it will just come along with the collection of all other legacy AT commands that they support.
So if the modem supports AT+CMUX you should be good to go. I have no experience or recommendation with regards to client protocol libraries.
I am using 2 esp8266 wireless modules to establish bidirectional wireless communication between 2 arduino boards (one mega and one uno) without the use of any earth based technologies (i.e. radio frequencies, wifi which relies on earth sattelites, etc.). My solution was to use the esp8266 to establish a private area network with both esp's acting as a station and an access point (AT+CIPMODE=3). Unfortunately, this solution has proven to be more of a hassle than it was worth.
To start, I have the esp's each wired according to this diagram
When I first started out, the red LED was on and the blue LED was off. During this time, I was able to send AT commands, establish the server, and achieve the communication I required by entering commands directly to the serial monitor. After this, I started writing a library using the SoftwareSerial library to allow me to issue commands directly through the program to set up the esp as needed upon start up of my script. Before doing this, I changed the baudrate to make sure it was running at 9600, and entered the AT commands in the serial monitor to make sure everything was working properly and it still worked.
After I began writing the library, before uploading the code with a test of the library I noticed the blue LED was lit solid now. Noticing this, I reuploaded the barebones script (I haven't uploaded the library code to the arduino yet) and the esp was no longer receiving the AT commands.
Does this indicate an issue with the board which I can fix or does this mean the board is done?
With my deadlines approaching fast in about 3 weeks it is crucial I get this wireless communication working so if this is an issue with the board, I'm going to have to scrap the esp's and use a different way of communicating. So my second question is, if this is the case, what are other viable options for establishing this communication? I have used xbee's before and while that would be ideal, they fall out of the budget I have been alotted so I need to keep it under $50 for this. If bidirectional communication is not possible for that price I can live with one way because I just need to get this system working. Basically I just need to transmit a single byte of data.
I realize this response is a little belated, and I hope you got it sorted: I've started working with the ESP8266 myself in the last few weeks, and hence why I was looking around for tutorials on direct communication between 2 units, when I found your post.
From what I've been able to ascertain, the AT commands are a part of the 'firmware' which ships with some modules. The Arduino code however starts loading onto the chips at memory address 0x0000, which is the same address that the firmware update tools use.
In other words, I believe that with the Arduino-coded program running on there, you lose the AT command functionality.
If you find a firmware update tool for the ESP8266 (plenty online) you'll get back the AT commands.
I suppose though the real question is why would you want to? It seems that the AT commands are just a way to treat the ESP as a dumb WiFi antenna. With the Arduino code, you're actually treating it as a micro-controller in its own right.
I am currently working on a project for my university course. I am design a device which will be an intermediate interface between the computer and a USB flash drive, i.e. data go from computer->my device->USB drive.
One of the functions I want on this device is to be able to detect if there is any data activity going on, and send this information to the microcontroller. I don't need to know anything about the data itself, just whether there is data being transferred.
I've done some research online about how USB works, but I can't seem to find a good way of doing this. I have spoken to a tutor at uni. Apparently this is "very easy" to do, but I don't really know how. Can anyone suggest some ideas? Thanks very much.
In this case the simplest way is to use additional soft which can log USB protocol as well as a microcontroller, like USBlyzer (http://www.usblyzer.com/) or USB data capture (http://www.eltima.com/products/usb-capture/)
You need to insert your flash drive to device which is plugged to USB port in your computer. Then run USB data analyzer software and find the USB port. That's all! After that you can monitor and analyze all data between microcontroller and the app. Moreover, you can save and export captured data
Your tutor not quite right.
USB bus always have activity, even if no data transferred.
Carefully read USB specification (http://www.usb.org/developers/docs/), especially 'Protocol layer' section. Some basics you may read in 'USB in a nutshell' article.
Explore bus with oscilloscope.
Also you may use software analyzers like http://desowin.org/usbpcap/ or http://freeusbanalyzer.com/ to explore data on bus.
I think, will be enough to capture all packets on bus with external microcontroller, measure their duration and sort waste SOF packets and valuable data packets.
Sure, your microcontroller must be fast enough, to keep pace of USB 2.0 bus. Detection of activity of low-speed devices, like keyboard, will be much simplier, and may be done even with arduino.
You are trying to make a protocol analyzer like catc http://teledynelecroy.com/protocolanalyzer/protocolstandard.aspx?standardid=4
These is a device which is like man in middle for any network.
You would need your device to act as USB host(master) and USB device(slave) at same time. Also while copying data from one port to another you need to make a data copy for analysis. USB devices have critical timing requirements and operate at high data rate. So you might need good amount of processing power in your device. Also this makes such analyzers expensive.
If there is no requirement for analyzing USB protocol, you can have device that will analyze slower buses like uart,spi I2c etc.You can check hobby manufacturers like sparkfun for such tracing devices.
Best luck with your endeavor
I'm working on code that communicates via serial port between different languages and different platforms, and I'd like a single test mechanism I can use that'll hook up to a serial port and then run a series of scripted conversations (send "this", wait for "that", pause 2s, wait for "that" again etc). Messages are binary. I could write something, but there must already be something out there for this that's had decades to mature, so not only would I be re-inventing the wheel but I'd probably be making it triangular. Does anyone know of such a thing? Can be either Windows or Linux.
I´m not sure to understand your question... If what you are developing is a propietary (your own) serial protocol to execute some tasks from different platforms (with different programming languages), all talking your protocol, and what you want to do is to plug a serial cable from/to PC-device and send from the PC serial commands of your protocol to the device (could be another PC) to test your software, yes, there are plenty of software to send serial data:
With some limitations on the free versión:
http://www.commfront.com/commfront-downloads.htm
A full free software from Extron (you can send a script file):
http://www.extron.com/product/software.aspx?id=dataviewer&s=5
There are many more, specially if want to waste your money, but those are the ones i´ve worked with for some years and works great.
What is the difference between a Relay Controller and a Microcontroller?
I'm looking into Arduino boards and am just getting into electronics, so I wanted to know the difference.
I know this is not a programming question, but I am developing in PHP and would like to know what the difference is before I start to code to make sure I'm going down the right path.
Those two devices are very different. Depending on exactly what you're trying to do, you may be able to use either, however. You'll have to tell more about your goal.
If you're switching high-current or high-voltage loads on and off, you'll need some sort of relay (or perhaps a large FET). If your current and voltage requirements are sufficiently low (5V, 40ma), you may be able to drive your load directly with the Arduino's output pins.
The Arduino is a microcontroller. That means it's an entire computer, just simplified. It has RAM, registers, an ALU, etc. Microcontrollers are generally specialized such that instead of interfacing to peripherals using some kind of bus like in a desktop computer processor, they have I/O capabilities built in, often simply in the form of outputs that can be set high (the input voltage, usually 5V) or low (0V) programmatically. The Arduino probably uses its own programming langauge, although there may be more than one language available for it (I've never used one). I doubt PHP is one of those langauges.
The relay controller is exactly what the name implies -- a simple circuit that controls some relays. Relays are electrically actuated switches. There's no intelligence in the relay controller. It can't be programmed; it must be controlled externally via USB. If you're attempting to interface with it from PHP on a desktop/server computer, this is probably your best choice. You're right that it's expensive. You could probably build your own for a fraction of the cost, especially if you're willing to use the parallel port on your computer (googling for how should give simple instructions). It's worth noting that that relay controller, and presumably most others, likely contain some kind of microcontroller with the I/O pins connected to circuitry that increases the current and/or voltage to the point where it can drive the relay, which in turn switches the load.
Hmm... only very vaguely programming related :) I think we may need another StackOverflow for electronics. Maybe SparkOverflow?