Related
I need to cover a district with a LoRaWAN network for air quality sensors. I know that the LoRa/LoRaWAN technology is the perfect solution when Line of Sight is maintained, but is there any easy way to determine how many gateways are needed in rural areas? I amning plan to use Kerlink Wirnet iStation V1.5 as gateway and ESP32-based CO2 sensors. Many thanks in advance.
You definitely don't need line of site for LoRa communication.
The easiest, and most accurate way to estimate the number of required gateways is to do a field test with one single gateway and a test device (e.g.: an Adeunis Field Tester). This way you can check what the longest distance between an end device and the gateway can be. Using that information you can calculate the required density of base stations.
If you register for a free account on Actility's ThingPark Community Portal and you connect your Kerlink gateway to the ThingPark Network Server, you will be able to use Actility's Network Survey Tool that can visualize the coverage of your gateway an a map.
If you want to make a rough estimation I would say that in a rural environment, where devices are outdoor and the gateway antenna is on a 20m height pole or on top of a 20 height building the range of a gateway is around 1-3 km. If the end devices are indoors (in rooms having windows) this range is 0.5-1.5 km.
You could also use The Things Stack community edition (formerly known as TTN, The Things Network) in conjunction with ttnmapper.org. Note that there is currently a transition going on from TTN (V2) to The Things Stack V3, see the notice on the webpage. This method uses field tests similar to the system proposed in Norbert Herbert's answer; any simple node is sufficient because the GW's metadata are evaluated. You can track you field test live on a smartphone. As LoRaWAN coverage strongly depends on the gateway's placement, it should be at least similar to the intended position, better be the planned position proper.
For a dry run without any hardware, you may also have a look at the freeware program Radio Mobile by Roger Coudé VE2DBE, with more info by Remko Welling PE1MEW here. The program lets you simulate radio connections in a wide variety of settings, including a complete mapping of a region with multiple gateways.
Line of Sight is not always needed. There are many factors that will affect the reach of your modules, including the terrain (hills can get in the way, especially higher ranges), the settings you would use for your LoRa or LoRaWAN network, and where you position your gateway(s) – when using LoRaWAN – or transceivers, when using LoRa.
I live in a mixed environment, half hills and jungle and half dense, high rises, and I get about 10 km coverage, no LoS, and more if I get LoS from a height, both with LoRa and LoRaWAN, although reliability is not always guaranteed.
But first you have to decide whether you will go the LoRa or the LoRaWAN – this has implications on both the hardware and software budget: while LoRaWAN requires more equipment, and more onerous, it will simplify the setup cost, software-wise. I am very much a LoRa guy myself, but I do recognize the benefits of LoRaWAN for quick developments.
But it'd be cheap to do a first test with a couple of LoRa devices, to check how far you can reach in your region.
I would like to know if there's any controller such as arduino or any other microcontroller that can be programmed to run VLC player embedded in its system. It is probably the best open source player. It would be nice if it could run on a standalone controller, and just plug in your usb to the controller and play videos.
The barebone mini systems are way too expensive around 200 to 400 dollars, and that would be an easy approach, but not cost effective.Thanks for reading.
Generally speaking, no, as most "microcontrollers" lack the memory (or external memory bus) and horsepower needed to do software video decoding.
That generally is a task which falls more to "system on a chip" (SOC) designs, which today are increasingly packaged with hundreds of megabytes of memory stacked on top of a several hundred MHz processor, which may have additional special function hardware acceleration. Things like the beaglebone family, raspberry pi, and recent set top boxes and smart phones, and of course pocket cameras would be examples.
Note that some of the SOC based boards are not really any more expensive than an Arduino, especially by the time you add I/O shields to the latter. That's because they are able to leverage modern high density integration and the economies of scale of the consumer-device chip marketplace, to inexpensively put a lot of functionality on one or two chips, which would be far, far more expensive to crudely duplicate using a lot of physically discrete parts in the manner of an Arduino + accessories solution. And an Arduino is so many orders of magnitude too slow that the first accessory you would have to add to it would be a stand-alone hardware video decoding IC.
I agree with Chris.
Microcontrollers doesn't have enough memory to decode videos. You need to select some microprocessor with video processing available. On the other side you can get some cheap processors with android capability.They are available for 35-40 $. And gives smooth HDMI output. (Not sure about Plug into USB)
The barebone mini systems are way too expensive around 200 to 400
dollars, and that would be an easy approach, but not cost effective.
Raspberry Pi, about $30 give or take. Beaglebone black $45, white $89. pcDuino Lite, $39, pcDuino Dev $59, I could do this all day...
As everyone has already said, you wont port such a heavily operating system dependent program to a microcontroller, for a number of reasons, memory, processor requirements, video, and so on.
if you could say take a stm32f4 or something on the high end of microcontrollers, and create some video player for specific format or formats, the man hours involved would take a fair number of sales to overcome the cost. Why spend a few months on a project when you can have a raspberry pi or beaglebone shipped in a couple of days? (or a Roku or Apple TV at a local store).
my question is : how can build single board computer like Raspberry Pi for run OS ?
user ARM micro processor and debian arm os , can use USB and etc.
like raspberry pi and other single board computer
i search but find nothing for help me !!! :(
The reason you can find nothing is probably because it is a specialist task undertaken by companies with appropriate resources in terms of expertise, equipment, tools and money.
High-end microprocessors capable of running an OS such as Linux use high-pin-density surface mount packages such as BGA or TQFP, these (especially BGA) require specialist equipment to manufacture and cannot reliably or realistically be assembled by hand. The pin count and density necessitates the use of multi-layer boards, these again require specialist manufacture.
What you would have to do if you wanted your own board, is to design your board, source the components, and then have it manufactured by a contract electronics assembly house. Short runs and one-off's will cost you may times that of just buying a COTS development or application board. It is only cost-effective if you are ultimately manufacturing a product that will sell in high volumes. It is only these volumes that make the RPi so inexpensive (and until recently Chinese manufacture).
Even if you designed and had your own board built, that in itself requires specialist knowledge and skill. The bus speeds on such processors require very specific layout to maintain signal integrity and timing and to avoid EMC problems. The cost of suitable schematic capture and board layout software might also be prohibitive, no doubt there are some reasonably capable open source tools - but you will have to find one that generates output your manufacturer can use to set-up their machinery.
Some lower-end 8 bit microcontrollers with low pin count are suitable for hand soldering or even DIP socketing, using a bread-board or prototyping board, but that is not what you are after.
[Further thoughts added 14 Sep 2012]
This is probably only worth doing if one or more of the following are true:
Your aim is to gain experience in board design, manufacture and bring-up as an academic or career development exercise and you have the necessary financial resources.
You envisage high production volumes where the economies of scale make it less expensive than a COTS board.
You have product requirements for specific features or form-factor not supported by COTS boards.
You have restricted product requirements where a custom board tailored to those and having no redundant features might, in sufficient volumes be cost-effective.
Note that COTS boards come in two types: Application modules intended for integration in a larger system or product, and development boards that tend to have a wide range of peripherals, switches, indicators and connectivity options and often a prototyping area for your own use.
I know this is an old question, but I've been looking into the same thing, possibly for different reasons, and it now comes up at the top of a google search providing more reasons not to ask or even look into it than it provides answers.
For an overview of what it takes to build a linux running board from scratch this link is incredibly useful:
http://hforsten.com/making-embedded-linux-computer.html
It details:
The bare minimum you need in terms of hardware ( ARM processor, NAND flash etc )
The complexities of getting a board designed
The process of programming the new chip on the board to include bootloaders and then pointing them to a linux kernel for the chip to boot.
Whether the OP wishes to pursue every or just some of these challenges, it is useful to know what the challenges are.
And these won't be all of them, adding displays, graphics and other hardware and interfaces is not covered, but this is a start.
Single board computers(SBC) are expected to take more load than normal hobby board and so it has slightly complicated structure in terms of PCB and components. You should be ready to work with BGA packages. Almost all of processors in SBCs are BGA (no DIP/QAFP). Here is the best blogpost that I recently came across. Its very nicely designed and fabricated board running Linux on ARM processor. Author has really done a great job at designing as well as documenting the process. I hope it helps you to understand both hardware and software side of SBCs.
A lot of answers are discouraging. But, I would say you can do it, as I have done it already with imx233. Its not easy, its not a weekend project. My project link is MyIMX233.
It took me about 4-5months
It didn't cost me much, a small fine tip soldering iron is what I used.
The hard part is learning to design PCB.
Next task would be to find a PCB manufacturer with good enough precision, and prototyping price.
Next task would be to source components.
You may not get it right, I got the PCB right by my 3rd iteration. After that I was able to repeatedly produce 3 more boards all of which worked fine.
PCB Design - I used opensource KiCAD. You need to take care in doing impedance matching between RAM and processor buses, and some other high speed buses. I managed to do it in 2 layer board with 5mil/5mil trace space.
Component Sourcing - I got imx233 LQFP once via mouser, and once via element14.
RAM - 64MB tssop.
Soldering - I can say its easy to mess up here, but key is patience. And one caution don't use frying pan and solder past to do reflow soldering. I literally fried my first 2 processors like this. Even hot air soldering by a mobile repair shop was also not good enough.
Boot loading image - I didn't take much chance here, just went with Archlinux image by olimex.
If you want to skip the trouble of circuit designing between RAM & processor, skip imx233 and go for Allwinner V3S. In 2017/2018 this would be easiest approach.
Bottom line is I am a software engineer by profession, and if I can do it, then you can do it.
Why not using an FPGA board?
Something with Zynq like the Zybo board or from Altera like the DE0-Nano SoCKit.
There you already have the ARM core, memory, etc... plus the possibility to add the logic you miss.
I am new to the locating hardware side of embedded programming and so after being completely overwhelmed with all the choices out there (pc104, custom boards, a zillion option for each board, volume discounts, devel kits, ahhh!!) I am asking here for some direction.
Basically, I must find a new motherboard and (most likely) re-implement the program logic. Rewriting this in C/C++/Java/C#/Pascal/BASIC is not a problem for me. so my real problem is finding the hardware. This motherboard will have several other devices attached to it. Here is a summary of what I need to do:
Required:
2 RS232 serial ports (one used all the time for primary UI, the second one not continuous)
1 modem (9600+ baud ok) [Modem will be in simultaneous use with only one of the serial port devices, so interrupt sharing with one serial port is OK, but not both]
Minimum permanent/long term storage: Whatever O/S requires + 1 MB (executable) + 512 KB (Data files)
RAM: Minimal, whatever the O/S requires plus maybe 1MB for executable.
Nice to have:
USB port(s)
Ethernet network port
Wireless network
Implementation languages (any O/S I will adapt to):
First choice Java/C# (Mono ok)
Second choice is C/Pascal
Third is BASIC
Ok, given all this, I am having a lot of trouble finding hardware that will support this that is low in cost. Every manufacturer site I visit has a lot of options, and it's difficult to see if their offering will even satisfy my must-have requirements (for example they sometimes list 3 "serial ports", but it appears that only one of the three is RS232, for example, and don't mention what the other two are). The #1 constraint is cost, #2 is size.
Can anyone help me with this? This little task has left me thinking I should have gone for EE and not CS :-).
EDIT: A bit of background: This is a system currently in production, but the original programmer passed away, and the current hardware manufacturer cannot find hardware to run the (currently) DOS system, so I need to reimplement this in a modern platform. I can only change the programming and the motherboard hardware.
I suggest buying a cheap Atom Mini-ITX board, some of which come with multi - 4+ RS232 ports.
But with Serial->USB converters, this isn't really an issue. Just get an Atom. And if you have code, port your software to Linux.
Here is a link to a Jetway Mini-Itx board, and a link to a 4 port RS232 expansion module for it. ~$170 total, some extra for memory, a disk, and a case and PSU. $250-$300 total.
Now here is an Intel Atom Board at $69 to which you could add flash storage instead of drives, and USB-serial converters for any data collection you need to do.
PC104 has a lot of value in maximizing the space used in 19" or 23" rackmount configurations - if you're not in that space, PC104 is a waste of your time and money, IMHO.
The BeagleBoard should have everything you need for $200 or so - it can run Linux so use whatever programming language you like.
A 'modern' system will run DOS so long as it is x86, I suggest that you look at an industrial PC board from a supplier such as Advantech, your existing system may well run unchanged if it adheres to PC/DOS/BIOS standards.
That said if your original system runs on DOS, the chances are that you do not need the horsepower of a modern x86 system, and can save money by using a microcontroller board using something fairly ubiquitous such as an ARM. Also if DOS was the OS, then you most likely do not need an OS at all, and could develop the system "bare-metal". The resources necessary just to support Linux are probably far greater than your existing application and OS together, and for little or no benefit unless you intend on extending the capability of the system considerably.
There are a number of resources available (free and commercial) for implementing a file system and USB on a bare-metal system or a system using a simple real-time kernel such as FreeRTOS or eCOS which have far smaller footprints than Linux.
The Windows embedded site ( http://www.microsoft.com/windowsembedded/en-us/default.mspx )
has a lot of resources and links to hardware partners, distributors and development kits. There's even a "Spark" incubation project ( http://www.microsoft.com/windowsembedded/en-us/community/spark/default.mspx )
What's also really nice about using windows ce is that it now supports Silverlight as a development environment.
I've used the jetway boards / daughter cards that Chris mentioned with success for various projects from embedded control, my home router, my HTPC front end.
You didn't mention what the actual application was but if you need something more industrial due to temperature or moisture constraints i've found http://www.logicsupply.com/ to be a good resource for mini-itx systems that can take a beating.
A tip for these board is that given your minimal storage requirements, don't use a hard drive. Use an IDE adapter for a compact flash card as the system storage or an SD card. No moving parts is usually a big plus in these applications. They also usually offer models with DC power input so you can use a laptop like or wall wart external supply which minimizes its final size.
This http://www.fit-pc.com/web/ is another option in the very small atom PC market, you'd likely need to use some USB converters to get to your desired connectivity.
The beagle board Paul mentioned is also a good choice, there are daughter cards for that as well that will add whatever ports you need and it has an on board SD card reader for whatever storage you need. This is also a substantially lower power option vs the atom systems.
There are a ton of single board computers that would fit your needs. When searching you'll normally find that they don't keep many interface connectors on the processor board itself but rather you need to look at the stackable daughter cards they offer which would provide whatever connections you need (RS-232, etc.). This is often why you see just "serial port" in the description as the final physical layer for the serial port will be defined on the daughter card.
There are a ton of arm based development boards you could also use, to many to list, these are similar to the beagle board. Googling for "System on module" is a good way to find many options. These again are usually a module with the processor/ram/flash on 1 card and then offer various carrier boards which the module plugs into which will provide the various forms of connectivity you need.
In terms of development, the atom boards will likely be the easiest if your more familiar with x86 development. ARM is strongly supported under linux though so there is little difficulty in getting these up and running.
Personally i would avoid windows for a headless design like your discussing, i rarely see a windows based embedded device that isn't just bad.
Take at look at one of the boards in the Arduino line, in particular the Arduino Mega. Very flexible boards at a low cost, and the Mega has enough I/O ports to do what you need it to do. There is no on-chip modem, but you can connect to something like a Phillips PCD3312C over the I2C connector or you can find an Arduino add-on board (called a "shield") to give you modem functionality (or Bluetooth, ethernet, etc etc). Also, these are very easy to connect to an external memory device (like a flash drive or an SD card) so you should have plenty of storage space.
For something more PC-like, look for an existing device that is powered by a VIA EPIA board. There are lot of devices out there that use these (set-top boxes, edge routers, network security devices etc) that you can buy and re-program. For example, I found a device that was supposed to be a network security device. It came with the EPIA board, RAM, a hard drive, and a power supply. All I had to do was format the hard drive, install Linux (Debian had all necessary drivers already included), and I had a complete mini-computer ready to go. It only cost me around $45 too (bought brand new, unopened on ebay).
Update: The particular device I found was an EdgeSecure i10 from Ingrian Networks.
USBCELL rechargeable batteries - charged using the USB port
These came out a while back and are worth the money, in my opinion.
I searched for software specifically made to monitor the battery level of USBCELL batteries and got nothing. There are some USB port monitor programs out there which might tie in somehow, but they could be unrelated also.
Anyway..
Is it possible to write a program that tells you the battery level of the USBCELL when its plugged in and is charging?
EDIT
If it makes any difference, the batteries have status lights that turn on when plugged in.
There is nothing to install (optional or required) to get these to work.
its USBCELL man here
Yes regular versions have embedded circuitry, though we do make a special USBCELL version (mainly currently for corporates), that is branded and has a downloadable USB charge monitor - that can carry cross promotions/discount codes. This is programmable, but not in the general retail version. Regular packs can also be branded for events, www.usbcell.com/customize.php
In the meantime, there is a special christmas USBCELL pack for gamers - http://www.usbcell.com/product/13 which is great for gifts
regards
USBCELL EcoMan
I don't have these batteries, nor have I used them, but the most likely situation is that there is internal circuitry inside the batteries that decides whether to pull power from the USB port.
A "normal" battery charger works the same way in that:
if there is power and the battery is not charged, draw power to charge the battery;
else do not draw power.
So, it is quite unlikely that you'll be able to monitor the battery's voltage, as there should be no reason for the battery to "communicate" upstream to the computer via USB.
Unless these batteries have a proprietary protocol to communicate their status, you are out of luck.
The standard specifications (E/O/UHCI) do not provide for any information beyond the "Port Power" bits to indicate that the hardware is supplying power to the port (not if its being drawn by the device).
Some embedded systems offer more extensive information, but it comes from custom on board logic. (Usually a power circuit connected to the USB port, and not part of the actual USB controller).
The USB Battery Charging 2.0 specification, should address these issues. But it will be quite a while before products supporting it hit the market.
If you do find a trick, keep us posted !