I've been out of the loop on ZigBee for a while now. Who has the most mature Zigbee stack? Is it Microchip, Chipcon, or Atmel?
Are there RF modules down to less than US$10 yet?
I recall there was some licensing issues with certain stacks a while back...
(This question was originally asked in 2009. As of 2012, I don't think Ember is a leading stack anymore. It seems that Texas Instruments has become the dominant chipset/stack... Although, their stack does seem to be locked to using IAR's terrible IDE which would make me think twice about using it.)
We've been using the Ember Corporation SoC chips for some time now. I'm very impressed with their chip, tools, and utilities. Some companies are using them for plug in modules, Digi's XBee and Telegesis are two that we have worked with.
Ember also has the ZCL and the HA and SA profiles implemented, ready for you to use.
www.ember.com
I've done some work with the TI stack. It's... ok I guess. The IDE limitation makes it pretty awful, and there are some rough edges. Documentation isn't all that great, and when you hit a certain level you run into a closed-source driver module (this might be a common limitation among vendors, haven't done enough with them all to know offhand.) Still, after having built a proof-of-concept demo with the TI stack, I'm still looking for alternatives.
Saw a bunch of them at ESC and CES. For reference, some options (no particular endorsement either way, in alphabetical order)
Anaren - their modules use the TI stack: http://anaren.com/air
Atmel - http://www.atmel.com/products/microcontrollers/Wireless/software.aspx
Ember - http://ember.com/products_zigbee_chips.html
Marvell - eg the 88MZ100 part - http://www.marvell.com/wireless/
NXP - seem to have a "JenNet" stack - http://www.nxp.com/products/rf/wireless_microcontrollers/
TI - http://www.ti.com/z-stack
Any other suggestions/alternatives would be welcome.
Two years later in 2011, Ember's ZigBee stack is the clear winner. Ember has enough of the ZigBee market to be an effective standard, and most plugin modules, including Digi's Xbee and Telegesis are built on top of Ember's SoCs.
Chipcom/Texas Instruments has some different interpretations of the protocol from Ember and in general their stack is less flexible. If you don't want to scan networks and join the way they recommend, you are basically out of luck.
I haven't used any other stacks.
Related
My project is to create an interactive program using the Micro:bit microprocessor I'm building a game which uses a drill motor as a controller of sorts reading the rotation direction and speed as inputs for control
but my mentor also said it would be cool to power the board at the same time as the game is running so now I hit the situation where once I stop turning to change direction or my speed goes below transmitting 3.3 volts to power it then the game restarts and I lose all progress
I had the Idea of using a second micro:bit as a sort of storage place being powered by my computer and the two continuously communicating sending back player position and other objects on the LED's
but i can't figure out how to get the two Micro:bit's to talk to each other
If someone could just point me in the right direction or even set up some sort of communication to nudge me in the right direction as I start moving forward
i'm a high school student who doesn't know as much as I pretend to so I'll probably need a lot of help (i am more advanced then most in my class at this sort of thing so think of me as a tech gifted teenager thrown in with college students losing my undeserved ego day by day LOL) please help me somehow I'm currently completely lost
You won't be able to use Bluetooth for the reasons indicated in the documentation (not enough memory): http://microbit-micropython.readthedocs.io/en/latest/ble.html
However, there is an incoming implementation of the lighter radio module, which would allow you to send simple data: https://github.com/bbcmicrobit/micropython/pull/283
The proposed documentation can be found in: https://github.com/bbcmicrobit/micropython/pull/305
As you can see in GitHub, at the time of writing it has not yet been merged into micropython. So if you'd like to try it you would have to clone the repository, apply the patch and build it from source. Keep in mind there is risk for the API to change, as there are still discussions about it.
Alternatively, as Sean has mentioned, you can use the C++ DAL implementation of the radio module to get something running on the meantime. Or if you prefer, the blocks and touch develop languages also offer radio functionality.
I don't think there is a way to do this in micropython (or at least simply), but the microbit runtime docs describe that, as well as supporting bluetooth, the 2.4 GHz radio:
However, it can also be placed into a much simpler mode of operation based that allows simple, direct micro:bit to micro:bit communication
In order to use this, you might need to write in c++ using the mbed environment (or offline) - but I hope this at least gives you a pointer to start from.
Here's a blog post describing how to do data logging using two microbits in exactly the configuration you describe.
http://www.suppertime.co.uk/blogmywiki/2016/06/microbit-logger
How to get the two micro:bits to talk to each other
As of 2016, you can! First check micropython has the radio module
import radio
If you get the error "No module named 'radio'", use https://codewith.mu/
Then follow the radio tutorial https://microbit-micropython.readthedocs.io/en/latest/tutorials/radio.html
The API is
https://microbit-micropython.readthedocs.io/en/latest/radio.html
I've ripped open an old Pentium desktop. The main board is a Zida 5svx. I got to know from the manual (which i downloaded from the internet) the location of the ROM chip on the board, and took it out. It was mentioned in the manual that the chip was a Flash EEPROM.
Now, what I am interested in is this: Is there a way to erase the ROM and flash it with, say a C program to blink an LED (i know this might put you into a fit of laughter, but read on all the same), or control a motor?
I also want to know if I can construct a mega-sized micro-controller with the left-over Pentium, some MBs of RAM, and this ROM.
Any suggestions?
P.S: I know that such a uC will require appropriate power supply setup and things.
The key is in getting and deeply studying the manufacturer's datasheets for each device you remove and wish to reuse. I am supposing that since you asked the question that you did that you are not a professional electrical engineer - that's OK, but you will need to do hours, days, or weeks of study to truly understand the datasheets well enough to successfully reuse your motherboard chips because they are written for professional engineers with years of experience, and unfortunately they were not written to be understood by hobbyists. If you can succeed in acquiring and thoroughly understanding all of the datasheets (and the related user's guides as well for the more complex chips) then you have made it to the point where you might be able to start a custom design based on your recovered parts, on paper at least. In order to test your design and insure that each part of it is working will require at least an oscilloscope and volt meter - and the knowledge of how to use them. An understanding of basic electronics is essential, you will not succeed without it. Very good soldering/rework/assembly skills will be required as well if you hope to have your design truly work - you can do everything else right and it can still fail if your skills in this area are lacking. There is simply not enough time for me to advise you on everything you will need to know - but if you are motivated, dedicated, and you don't give up when setbacks and roadblocks occur (and trust me, they occur all too frequently for even the best engineers and best designs) - meaning that you are not easily frustrated when things don't work - then you have a chance at success. I wish you all the best, and try to have fun while doing it (important in case fun is all you ever get out of your project). :)
I have used and like the Atmel ATMEGA and ATTINY series microcontrollers, and think them quite good. One thing I am not terribly fond of though is the fact that they (and Microchip PIC uC family also) are all Harvard machines, meaning I can't really put external memory to use or execute out of RAM, only the flash.
While there are obvious advantages to this design, it makes it technically very difficult to do things like FORTH using an AVR or PIC. (I know there is at least one implementation, but it does not work like a normal FORTH and will wear out the flash rather rapidly)
FORTH was originally created for interactive machine control type systems where lots of flexibility was needed, so things like the Z80 or 6809 were used as microcontrollers with the control program executing out or RAM or some other storage device.
Does anyone know of current devices of similar complexity (preferably available in DIP packages) to the AVR/PIC that are von Neumman machines?
In addition to Freescale processors (that starblue has already pointed out), the Texas Instrument MSP430 family uses von Neumann architecture. However only the smallest ones are available in a DIP package.
UPDATE to include PIC32:
In my original post, I had forgotten that PIC32 microcontrollers have always been able to execute out of RAM, as demonstrated by this code example;and now Microchip has come out with the new PIC32MZ line of microcontrollers, with up to 2 MB of Flash and 512K of RAM which makes them feasible for fairly large RAM-based programs. Unfortunately none of them chips are available in DIP packages.
However Olimex, sort of the Bulgarian equivalent of SparkFun and Adafruit, has a PIC32-HMZ144 development board for $21.95 EUR, which is about $24. This is a smoking hot deal since the processor alone costs over $12 at Digi-Key. (There are other boards available from US suppliers from around $50 and up.)
The original PIC32MX line has twenty variants in 28-pin DIP packages, but they are limited to a maximum of 64K of RAM, still useful for some projects.
Farnell has a nice search function that let's you search for microcontrollers in DIP packages. Though you'll have figure out which families are non-Harvard by looking at the data sheets.
Take a look at the 68K ones and the HCS08.
Update: In the meantime some ARM Cortex-M controllers in DIP packages have become available, the LPC810M021FN8 and the LPC1114FN28 from NXP.
You might want to peruse the designs available at the OpenCores project. That is an open source project devoted to CPU core designs implemented in VHDL, Verilog, and similar FPGA design languages. There are complete and respectable implementations of classic 8-bit CPUs such as the 8080, 6502, and 8051. The 6502 I linked to claims to be cycle-accurate compared to the original chip. Others are functionally complete, but often have more modern buses and signals.
They won't (I think) be available in DIP packages, but you can always find breakout boards.
The designs are all open source, under a wide variety of licenses.
You may also have a look at the Zilog eZ80. Since they're binary-compatible with the old Z80, you should be able find a FORTH implementation that runs on them, but you'd probably need to run it on top of good old CP/M :)
Also, these are the only ones that I found that have the memory bus accessible from the outside, i.e. allow code execution from external memory.
The arm based ones, even the cortex-m3 claims to be harvard, but you can load programs into data ram and execute from that ram. it is really not harvard. Other arms are normally not harvard, some have external memory interfaces you can use to expand the internal resources.
This is actually not a question, but more of a related query. Why would you go to von-neumann in a microcontroller if the previous generation was harvard? Isnt it all win-win in terms of performance? other than complexity (which if the original PIC's can handle it, should not be that great) what are the downsides of having Harvard architecture?
The new Kinetis line of microcontrollers from Freescale puts an ARM Cortex-M4 inside a microcontroller package, and program code can be located anywhere in addressable space (RAM or FLASH, or even Flex Memory.)
The Kinetis Solution Advisor is a powerful selector guide that can help you find the micro you want. Memory from 32kB to 1MB, all the peripherals you could want, and pricing from under a dollar to around 10.
Besides Arduino, what other ways are there to learn hardware programming in a hands-on way? Are there any nifty kits available, either a pre-assembled robot, that you can program to move a certain way, or do certain things, or anything similar to that?
Atmel AVR and the PIC both have experiment boards that you can use solder stuff on to, usually they have a couple of buttons and some lights pre-soldered to the area. This let's you program/flash the microprocessor and play with the output pins. You can either write the programs in assembly or C.
Parallax have a number of kits. They have two product lines suited for "playing around", Basic Stamp and something called Propeller. The former is a small microprocessor that runs programs written in Basic (a tad disgusting ;)) and the latter runs something called Spin or assembly (well after compilation obviously.)
I would go with either AVR or the PIC. I've done PIC but I've heard good things about AVR, they seem to ship with better software.
At first look Microsoft's VPL sounds good, but when it comes to actually LEARNING how hardware works it goes a LONG way to hide those details from you. As a matter of fact it is pretty much designed for people who don't program, and is distastful to someone who's actually written embedded software. IF you just want to make stuff happen and not delve into the details it's fine, but if you want to get down to the metal like programming the "Arduino" boards it's not for you.
If you're used to something like the Arduino then something like the PIC will be an easy transistion. SparcFun Electronics has all sorts of DIY type projects and hardware available. If you have a decent bookstore around your area, I would suggest looking for "Circuit Cellar" magazine. It has articles on a monthly basis with project for someone looking to get into hardware projects, everything from homebrew Software Defined Radio to FPGA based 3D graphics. (Raytracing actually) Usually the authors describe the project in an article and "WHY" they made the decisions they did, a description and schematics of the hardware and provide a link to source code.
Cypress Semiconductor has one of the most interesting embedded processors on the market and several high quality dev boards for sale. The PSoC includes the ability to not only configure the software, but also to "drop in" software configured hardware such Analog to digital converters, serial I/O, Digital to Analog and Various amps and filters. It's a REALLY cool concept, and the "touch sensor" capability of the PSoC were actually used in several models of the IPod.
One thing about programming these little micros is they don't have a lot between you and the hardware, you get to see how things really work. It doesn't matter whether you're talking about an 8-bit microcontroller or a quad-core Pentium programming hardware is largely the same concept. You write to a memory mapped register for some piece of hardware like a serial controller, and the hardware responds in someway. If you program a baudrate generator in a PIC or PC it's largely the same idea, you write a value that will be used as a division factor from a given clock to achive a given baudrate. The numbers and names maybe different, but the concepts is the same. On a PC you may have to map to the PCI address of the card, which adds a some complications, but if you looked underneath the OS you would see that that was done just by writing values to registers simalar to programming a PIC to use a different "Page" of memory. Is it worth learning an 8-bitter? Well, there are approximately $5 billion dollars in sales of the little 8-bit micros today with projection only showing growth in that market in the future. I saw one reference that state the average car has 25 Microcontrollers in it. That's not too bad.
I haven't played with it much, but the iRobot looks pretty cool.
The ability to simulate how your robot will work which some of the other answers mentioned is nice, but there's nothing like seeing a real-life robot do what you programmed it to do. That, to me, is what really makes robots fun and cool.
There's the .NET Micro Framework.
It's incredibly simple to use/setup and there's lots of hardware being made to target this framework.
You should take a look at Microsoft Robotics Developer Studio which supports many different kits.
I have always been curious about gumstix. It seems more professional than arduino, and it aims at the Linux programmer. I cannot give you a real suggestion, as I've never played with it, but I would definitely go with one of this toys if I had to do and learn some cool hardware programming.
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I'd like to learn how to program in Assembler. I've done a bit of assembly before (during my A-Level Computing course) but that was very definitely a simplified 'pseudo-assembler'. I've borrowed my Dad's old Z80 Assembler reference manual, and that seems quite interesting so if possible I'd like to have a go with Z80 assembler.
However, I don't have a Z80 processor to hand, and would like to do it on my PC (I have windows or linux so either is good). I've found various assemblers around on the internet, but I'm not particularly interested in assembling down to a hex file, I want to just be able to assemble it to something that some kind of simulator on the PC can run. Preferably this simulator would show me the contents of all the registers, memory locations etc, and let me step through instructions. I've found a few bits of software that suggest they might do this - but they either refuse to compile, or don't seem to work properly. Has anyone got any suggestions? If there are good simulator/IDE things available for another type of assembler then I could try that instead (assuming there is a good online reference manual available).
I've found a few bits of software that suggest they might do this - but they either
refuse to compile, or don't seem to work properly. Has anyone got any suggestions?
Write one. You're best off picking a nice, simple instruction set (Z80 should be perfect). I remember doing this as a first-year undergraduate exercise - I think we wrote the simulator in C++ and simulated 6800 assembly, but really any language/instruction set will do.
The idea of "learning assembly language" these days is to get the idea of how computers work at the lowest level, only a select few (compiler writers, etc.) have any real reason to actually be writing assembly code these days. Modern processors are stuffed full of features designed to be used by compilers to help optimise code for speed/concurrent execution/power consumption/etc., and trying to write assembly by hand for a modern processor would be a nightmare.
Don't fret about getting your application production-ready unless you want to - in all likelihood the bits of software you've found so far were written by people exactly like you who wanted to figure out how assembly works and wrote their own simulator, then realised how much work would be involved in getting it "production ready" so the general public could use it.
You might want to check out the open source 8085 simulator "GnuSim8085", it's specifically meant to be used for educational purposes, and it was in fact written by student while preparing for his exams. It runs on both, Linux and Windows.
WinApe is a good emulator of an Amstrad CPC. The Amstrad CPC was a Home Computer produced in the 80's. It used a Z80 as its CPU. Using the emulator you can display a lot of the internals while programming. It includes a debugger and a disassembler for Z80 code.
If Your are on windows 8085 Simulator is the best choice.
It user interface is excellent than any other simulator. Also this simulator provide live view of memory map very time(also while in the execution).
But this one does not support Windows 98 or lower for that you need to check other simulators like GNUSim8085.
MipSim is FREE
Main Features of MIPSim 2
Built-in code editor with features like syntax highlighting and folding
Display register and memory values in different representations (signed integer, unsigned integer, hexadecimal and ASCII)
Set the block size (full-word, half-word, byte) of the memory cells for easier examination of the memory values
Change values of registers and memory cells with a single click even during simulation and debugging
Realtime user-interface updating allows you to see how values of registers and memory cells change during execution
Built-in debugger with step-by-step instruction execution, instruction skipping and breakpoint features
Tools for inserting ASCII, UNICODE strings and integer values to memory for testing of your code
Tools for checking duplicate or missing labels and instruction parameters
Save computer state (values of all registers and memory cells) so that next time you run the simulator you can continue from where you left!
Set the simulation speed - low speeds are great to trace your code and to see how it behaves
Encode instructions - produce machine code in either binary or hexadecimal representation
Catch assembly time and runtime errors
Easier debugging with descriptive error messages
Multi-threaded design - MIPSim doesn't get stuck (hopefully ;) even if the assembly code executed is erroneous or contains infinite loops
MIPSim API - make your own programs that can read from and write to the registers and memory of MIPSim, great flexibility for powerful testing!
Aim higher! Try and get a simulator for a more powerful assembly language. Remember, Z80 and 808x were low-end processors with low-end and awkward instruction sets.
Something like VAX from DEC was regarded as the Rolls-Royce of instruction sets. And then there are crazy Risc instruction sets that do some really strange things. Maybe you can find definitions of those so that you can have a crack at implementing them.
You may be interested in this for a Z80 simulator, and I've had good experiences with WinAsm.
You might also consider learning x86 assembly language, which you could do using in-line assembler in Visual Studio - although it's a larger instruction set than Z80, you would have the advantage of being able to use much better tools than would be available for the Z80.
I've also just remembered that the Keil 8051 and Arm tools have a simulator in the IDE - there are size-restricted versions of these available for free download from www.keil.com
If you happen to already know .NET, then this may be of use:
http://www.viksoe.dk/code/asmil.htm
It's a little bit limited, and may only work with .NET 1.1, but you could atleast use a "modern" IDE for it, and there are plenty of docs around for it.
<%# page language="Asm80386" %>
<%
Str: DB "Testing...", 0
mov eax, -2
cmp eax, 2
jle Label1
xor eax, eax
Label1:
lea esi, Str
push esi
call "Response.Write(string)"
pop esi
%>
<br>EAX: <%= eax %>
Another option, if you want to go "hard core" is get something like FreeDOS and VMWare, and use that. I'm sure a garage sale (car boot sale? yard sale?) or second hand book shop would have a copy of Peter Norton's old DOS interrupts bible. :)
Personally, I learned x86 asm by using Turbo Pascal (which I think is now free from Borland?), which had the ability to embed assembly instructions inside a function. Made it easier to setup the app, and I could focus on the stuff I wanted to do. I later used MacVAX at Auckland Uni, which was ok, but the VAX is very much dead - you may as well learn x86 :)
SimpSim is definitely worth a look. It's Windows only, but the feature set is pretty decent:
Main memory and register display
Built-in editor with syntax highlighting
Run, step, and break functions
This wouldn't make any meaning to you now but just for people stopping by. This is the best assembly code simulator I have come across with. Truly worth it!
http://www.emu8086.com/
Take a look at Thomas Scherrer Z80 Emulators for a listing of potential emulators you could use.
I write z80 asm for the ZX Spectrum (still, I know :) ) and use SJasmPlus to link to a spectrum emulator file. Lots of of the better Spectrum emulators like Fuse and ZXSpin have built in editors as well for on the fly debugging and patching.
When I was in college we used PIC microprocessors. They are made by a company called Microchip. They also have a great IDE with a chip emulator/simulator that can allow you to do things without actually having the chips.
Why use an emulator?
Download MASM or NASM and write good old 80386 architecture. Plenty of online samples and learning tools.
Plenty of real-world reason to use assembler!
there is a simulator which is Visual6502 for teaching fundemental of microprocessor architecture. It has a editor, assembler, I/O operation and animation of how to work a microprocessor. I is available at the following link.
http://www.pcsistem.net/visual/index.htm