Do you know a SDR (Software Defined Radio) kit with a 2.4GHz ISM band (2400MHz - 2483.5MHz) transceiver?
I need to perform some software defined radio including customised modulation. Also the price for one kit should be at maximum $1000. I know there are some extremely expensive solutions out there, but that is unfortunately not an option.
Also a low delay from reception to transmission is necessary, thus the GNU Radio + USRP solution is not usable.
Update:
I have taken a closer look at the USRP solution. From previous experience with the USRP + GNU Radio software I initially completely dismissed it as a solution in this case. I did that because I need to implement a packet radio protocol, thus I need precise bit synchronisation between input and output, and I need low delay that would allow me to transmit the next symbol following a received symbol, with a rate of 1000 kBaud.
From experience I know that the GNU Radio framework as default uses streaming chains of blocks, with very little synchronisation between TX and RX. Thus I suspect that using the USRP I would probably have to work directly with libusrp, and avoid most of the GNU Radio software. Am I mistaken in this?
I would suggest taking a look at the GNU Radio (gnuradio.org) SDR toolkit. Several projects (such as this one) have successfully used it for Bluetooth research.
There also exists development hardware designed for use with GNU Radio called the Universal Software Radio Peripheral which, with a suitable daughterboard for 2.4GHz development, costs around $1000.
I'd like to second GNU Radio. Specifically you are looking for the USRP not the USRP2. The USRP2 is still in heavy development(and out of stock) while the USRP is a stable platform for GNU Radio. The USRP motherboard cost $700. The daughterboard transceiver you want is the RX2400(2.4-2.9GHz, TX=50mW). You can find both of these boards at Ettus Research
Update six years later: USRPs come in the sub-1000$ range (B200/B210), they have very strict synchronization (ADC-rate accurate timed commands can control sampling) and coherency. GNU Radio supports these features through the gr-uhd interface.
Describing latency is quite a bit more complex, because it depends much more on how you deal with the data coming from any SDR frontend -- really, frontend latency isn't usually the problem when you try to do your processing on a general purpose OS, which makes no hard real-time guarantees. However, many just "hide" the latencies elegantly by employing timed commands and letting the frontend get the data early enough.
I recommend HackRF One wich is a half-duplex tranceiver form 1MHz to 6GHz and also has huge comunity support but is half the price of USRP.
EDIT
You now also have LimeSDR. It has 2 Rx and 2 Tx MIMO full-duplex channels and it's cheaper than tje HackRF. The only drawback may be the shipping time because at this moment there's no stock so you will have to pre-order.
We have successfully been using a professional development platform from Sundance Multiprocessor Technology (www.sundance.com). They do have some very affordable 2.4GHz/5GHz RF front-end solutions with integrated ADC/DAC and multiple DSP/FPGA processors.
University offers: http://www.sundance.com/docs/mimo_lte_booklet.pdf
Related
Background
I'm very new to electronics/IoT dev. I'm trying to create a solution to be able to read my wife's Car's CAN Bus signal (messages) and store it to an SD card. I hope to analyze the data and build a dashboard based on the car's telemetry.
This specific question is in relation to a chip (STM32F1) on an IoT board (MXChip AZ3166) I already own, which I hope to incorporate into my overall solution as the data acquisition layer.
For reference the:
Chips is the: STMicroelectronics STM32F103C8T6, 32bit ARM Cortex M3 Microcontroller
and the IoT board is the: (MXChip AZ3166 IoT DevKit)
Reading the MXChip AZ3166 board's spec and after doing some research, I have found out that the MXChip AZ3166 comprises two main chipsets:
Vendor
Part Number
Ref Link
STMicroelectronics
STM32F103C8T6
https://uk.rs-online.com/web/p/microcontrollers/1023545
MXChip
EMW3166
https://www.mxchip.com/en/products/module/54
Main Question
The product specification mentions the STM32F1 features Comprising of motor control peripherals plus CAN and USB full speed interfaces, it also states it has 1x CAN Channel. Does that mean I can interface the MXChip AZ3166 board featuring this chip via the GPIO pins to the CAB bus in my wife's car and receive the CAN Bus signals (I presume adhering to the
ISO 11898-1 CAN data communication protocol).
How would I find out which pins to connect to the CAN Hi & CAN low connections on the cars CAN Bus?
Concerning power, how would I determine that the CAN signal received doesn't fry the MXChip Board with a stated max Operation voltage of 3.3v?
Yes you'll want an MCU with a built-in CAN controller for communicating on a CAN bus. However, the CAN standard only covers the physical and data link layers. You need to know the application layer in order to meaningfully interact with a bus.
The application layer on a car may or may not be proprietary. It may even be encrypted. If you don't know what protocol is uses, then no can do. Reverse-engineering CAN protocols is hackish, hard and dangerous. Plugging into a CAN bus where you have no clue about timing considerations etc is also very dangerous.
But cars usually have an "on-board diagnostics" (OBD) port used for service purposes, with standardized application layers, through which you may have access to various parts of the car. There's lots of different standards for OBD and older ones didn't even use CAN. It depends on the car model.
In case of the OBD port the pinouts are standardized and you can find them on the Internet. Otherwise it is very simple to find out which signal that's CANH and CANL with an oscilloscope. CANH goes 2.5V +1V and CANL 2.5V -1V. A more hacky solution is to measure this with a multimeter, but it's perfectly possible since one signal with be slightly above 2.5V and the other slightly below.
CAN is standardized so if you have a CAN bus on the board, you connect there. In some cases there may be 12V supply wired together with the signal and that's the only one which could fry something.
Overall, please note that the project you describe here is very difficult and not a beginner task. It sounds as you have next to no experience of electronics/embedded systems, so I would recommend picking a far simpler project.
Furthermore, modifying car electronics or installing your own electronics in a car is illegal in most parts of the world. Third party type approvals with EMC tests are mandatory (and very expensive). If your car is involved in an accident and they find custom electronics without type approval in it, you could be facing serious legal consequences.
Is it possible to associate single wireless network interface controller (WNIC) with multiple Wireless Access Points (WAP) at a time? If not: why?
I've never heard about such a feature, so I assume it's technically impossible or fairly difficult and rarely implemented. Is it really that difficult/impossible to implement driver providing such a feature? Is it software or hardware difficulty?
I assume that TCP/IP protocols' specifications doesn't limit us at all because if I attach multiple WNICs to my computer, I can easily connect to multiple APs.
If it's software difficulty, than what's the actual problem? Does Linux/Windows kernel or WNIC's drivers limits it? Or maybe system libraries (like libc on GNU/Linux systems)?
If it's hardware difficulty, what actually limits us? Antennas? Using single radio frequency at a time? If yes, than why can't we implement frequency hopping (like Kismet does)? Because of lost packets during time spent on other channels? If yes, than can we associate WNIC with multiple routers working on the same channel (I know that channel overlapping is bad)?
Note: I'm not talking about dual band routers. I assume that we consider most common WNIC and AP which both work on 2.4GHz channels. If I have to put my question into OS context, than I choose GNU/Linux context.
Yes. The basic technique is that the client tells AP 'A' that it is going to sleep and then talks to AP 'B' while A is buffering frames for it.
Microsoft research worked this out a while ago:
http://research.microsoft.com/en-us/um/redmond/projects/virtualwifi/
Many low-level drivers support Wi-Fi interface virtualization (e.g. the BRCM wl command has options which support this).
Apple's AirDrop and MultiPeer features for OS X and iOS use a similar technique, but instead of talking to a 2nd AP they talk to a peer device.
I'd like to have an iPhone and an Arduino-based device talk to each other. Here are the requirements:
I want to fully rely on iPhone's built-in components without any peripherals (for example, HiJack).
The less configuration before the two can communicate, the better. This means a WiFi-based is not desirable, because we'll need to set up Wi-Fi credentials for the Arduino beforehand.
Bitrate is not important. Only a few bytes are exchanged.
As cheap as possible.
I see that Bluetooth 4.0 LE (for example, Stack Overflow question iPhone - Any examples of communicating with an Arduino board using Bluetooth?) meets my requirements, but are there any cheaper solutions?
One thing that came into my mind is sound - the way Chirp used to share data between two iOS devices, but I don't know if is feasible on Arduino and, if it is, how much it would be. Any other solutions?
I can think of a few options:
Bluetooth, you can get a cheap one from eBay for about $10
Wi-Fi using Electric Imp (cost around $30), which is very easy to setup using the brilliant BlinkUp technique. See the project ElectricImp, control central heating via iPhone for an example.
Chirp is a brilliant idea as well. From a hardware prospective I see it is feasible to do in Arduino; you just need a MIC circuit ($8) and speaker.
However, the real challenge is the software side, i.e., the algorithm that you will use to encode data as sound and vice versa. If such algorithm requires intensive calculation, you might not be able to do it in Arduino, and you can consider using an ARM-based microcontroller.
What sort of application can be considered to be the really business winner for automotive telematics applications related to image processing/computer vision ?
here are the criteria :
1. Innovative
2. Social
3. Fun.
Have you read the articles from the DARPA grand challenge winners?
DARPA site
Google Scholar
I believe the "DARPA Grand Challenge" style of automation meets your .1 requirement as there are plenty of innovation on that front.
But I still think that we are a good decade away from a fully autonomous vehicle, even though the technology is almost there. The main reason is that people are still very afraid of relenting control to the computer, even though it might be the safest choice.
The transition will be slow. More and more models will bring small chunks of automation, such as smarter cruise control systems (that's a big winner right now), autonomous parking (in the market for a while now) and anti collision systems.
Which brings us to your .2 and .3
The above mentioned systems are not fun, they are necessary [for increased safety]. Nowadays, Social Media and Fun don't really mix with driving because they distract the driver from its main task. In the future, when you're on the freeway in auto-pilot mode, you will be able to open your laptop and be free to do whatever you want, since computers will be always connected to the internet. So I don't believe the car itself needs to provide you that aspect of entertainment.
What I do believe it's a killer functionality for cars is the enhancement of intelligent comfort systems integrated with biometrics. Nowadays, cars already have things like personal keys that will make it adjust things like seat height and etc according to your preferences, but it would be much nicer if it could automatically identify who is the driver by some biometric feature (iris, etc) and adjust multiple parameters automatically. That's the end of the key. I'm not talking about seat and pedals adjustment, but transmission style (husband likes a more aggressive transmission), performance limiters (daughter cannot exceed 90% of posted limit... the car knows what the limit is according to where it is).
In my opinion, if you implement biometric recognition + autonomous navigation, the possibilities are endless.
Although none of the applications here use computer vision, they are probably the best once out there yet. They have received quite a bit of media hype.
Where would you recommend that I find a company to develop or buy a CD/DVD loading arm similar to: http://www.dextimus.com/
Preferably programmable via USB but if I only can get one with a serial interface that would be fine. Drivers dont matter - I can interface directly with the unit as my situation is very unique.
If you have some experience with electronics, you can give it a shot and build it yourself, like this or this.
I should add that the schematics and the source code are included, and in more details in the first project.
I suppose I might just shorten this by giving a list of resources first:
http://www.embedinc.com/ I trust this company to do good work. Expensive (actually, they are reasonably priced in the design community, but would be considered expensive by most hobbyists and individuals). Not great at people skills, but very very very good at what they do.
You should check out the various microcontroller communities and forums for hobbyists and professionals that can do this. Search for microchip, atmel, msp430, arm, powerpc, etc.
Sparkfun is a supplier to the electronics community - they have great forums where you can post your request, and you'll find people who might do it for fun with only the cost of materials. Might take longer, might not be as 'professional' or well packaged and delivered, but it might be your best low cost option.
There are many electronic design companies that could do this (for instance, I can do this sort of thing).
But there are many questions you haven't answered (and may not have researched) that could prevent success:
Is this patented?
What CD loading/unloading methods are not patented, are out of patent, or otherwise available?
What is your design goal - a one off just for you, or a device that can be built in the hundreds for industrial use, or a device meant for general office workers/consumers that is built in the millions?
Do you realize that this design qould surely cost mroe than simply buying one, if one is all you need?
As an example, assuming you don't need the nice enclosure and don't mind a 'prototype' look, just the mechanicals, electronics, and firmware design (no software on the PC) would likely be 100-250 billable hours for a design firm. At a cheap $90/hr, that's $9k to nearly $25k for one prototype. Add PC software and the nice enclosure, etc and you'll double that.
If you can find a local 'Make' group (techshop, GoTech, or similar) then you might be able to find a hobbyist that is willing to play with this idea for the cost of materials.
But if you define what your goal is, and give us an idea of your resources you may find a better answer.
-Adam
You can create a very nice simple solution using radio control servos. They come in many sizes, but even the small ones have enough torque to move a big arm to move a cd.
The real bonus with servos is that they normally have 180 degrees of rotation and internally have a variable resistor (rheostat) for positioning feedback. Positioning accuracy is normally within 1 degree of rotation which should be fine for a cd loader.
For picking up the CDs, nothing will beat a vacuum. I recommend a small battery powered vacuum cleaner. Funnel the suction into a 1/4 inch pipe. At the other end of the pipe a one inch diameter cup should provide more than enough lift from the small amount of suction.
As for the pile of blank CDs to be burnt, I would advise in moving the pile up rather than an arm down to it. probably having the top blank cd about 1/4 inch higher than the cd tray - By doing this, the arm only needs to rotate in one axis and the vacuum should be enough to suck the cd back out of the tray.
Now, for the electronics. For the servo control I suggest an rs232 serial servo controller. I've used the one from http://www.basicx.com/Products/servo/servo8t.htm as it also gives back torque information from the current draw.
For the low sample rate digital i/o, i suggest (for windows) inpout32.dll which is a dll to give you direct access to the bits of a parallel port. This will allow you to turn on the vacuum at the correct time and possibly sense when cd's have run out. Note that a parallel port can sink more current than it sources so for outputs you should connect to the 5v power line and set the output pin to 0 to turn on the output and 1 to turn it off.
The other nice option, which is very, very simple to interface and very cheap is to get hold of a picaxe from http://www.rev-ed.co.uk/picaxe/. These use a very simple programming language (a BASIC spin off) allowing you to read serial data in and control the servos and digital I/O on one chip. Last time I used one, the language was a bit simple - if statements had to jumped labels, else didn't exist.
If you do use a microcontroller and servos, it is best to use a dual voltage power supply as servos are noisy and can cause the microcontrollers to reset.
As for switching loads such as the vacuum on, you'll need to use a mosfet or (if money is no object) the simpler option, a solid state relay.
All digital inputs you use on the microcontroller should be pulled either to +V or ground with say a 5k resistor so they never float.
I cannot stress how simple and cheap the picaxes are. They have a built in interpreter so although code space is minimal on the small 8 pin units, they are programmable via a simple serial lead.
Good luck. Once you get into automation control, you'll never be able to stop. I'm in the middle of building a 3 axis CNC router so I can cut parts for other projects (I tell my girlfriend it's so she can cut out xmas decorations!).
You might want to contact Aaron Shephard about his Florian project.
I've found that a really easy board to control stepper motors or sorvos are produced by phidgets - the API is incredibly easy, and available for a vast array of platforms.