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.
Related
As the question says ,I want to monitor the value of power(watts) that some components consumption .especially the value of CPU , Memory and disk .
when I use aida64，I found that in computer/sensor ,there are some data about power consumption . I want to know how did it can get these data ?
I already have some idea ,but not sure which is the best way to solve this question :
there are some sensors on the motherboard ,we can use values of those sensors to calculate the real-time power.
according to different OS, we have some APIs that can get the utilization of cpu,memory throughout rate and disk I/O rate . Using this data ,we can build mode of power consumption about PC.if there are those APIs,where can I find them ?
maybe the hardware manufacturer like intel has already record the value of power in real-time ,they put the value into some special register in hardware .we can get the value through mapping into special memory location .
In my opinion ,the second way maybe the solution that most monitor software using .but I just don't know where can I get those API.
whats more ,our aim is to design an OS-independent real-time power monitor software. So, if there are any better solutions about this question ,I will appreciate your help .
Hmmm. I wasn't sure if I should post this as a comment or an answer. It is an answer but in the negative.
At this time, you can't create an OS independent software-based non-intrusive power monitor. By non-intrusive, I mean that you are not putting special instrumentation on the motherboard and other hardware. This is because the power technology being used by modern processors is in rapid flux, each new generation making significant advances. Additionally, the amount of power related information available to software from the hardware (via PMU events and the like) is continually increasing as more silicon real estate becomes available. For example, I believe that in the most current processors, you can get direct thermal information for key parts of the processor silicon, and temperature, power and current readings from various parts of the core and uncore.
The best you can do is to abstract the top layer of your monitor from the lower layers. Then the top becomes OS / HW independent while the lower levels need to be platform dependent.
Check out the PAPI APIs. Note that the APIs appear to give you the world, but are really just an API set. Someone still has to implement what's on the other side of the API.
Now if you can do your own special instrumentation, many (most?) motherboards and other hardware have measurement points (some undocumented) that provide thermal, current (and so power) information. This information is important for debugging devices and platforms.
I need to read GPS coordinates using a VB.NET program directly from a GPS device connected to the computer via USB (bluetooth also OK but prefer USB). My constraints are:
The computer running the software is NOT connected to the internet. It is a stand-alone machine in a moving vehicle.
I need to be able to read GPS coordinates from the device while the vehicle moves and use the device to perform location-aware queries on a local database
The GPS device can be anything (e.g. Garmin GPS or GPS card without display), as long at it can be purchased off the shelf or over the internet.
The user group for this solution is quite small (about 40 users).
I have already checked out GPSGate (http://gpsgate.com/) and emailed my requirements to them. They replied, and I quote: "I am sorry but we have no product for you." (end of reply).
I also checked out Eye4Software) and tried using their demo product but it does not pick up my Garmin Nuvi via USB. They responded to my questions but unfortunately their OEM product is an ActiveX dll and I am looking for a .NET based solution.
So if anyone has a "home-grown" solution based on the .NET framework, that can be easily duplicated, I would really appreciate it. Many thanks!
Most of the USB GPS pucks will speak a standardized protocol called NMEA 0183. There are several .net protocols out there that decode this protocol, see here for some pointers to get started.
So, if when shopping around you just check that the device is able to generate NMEA you should be up and running in a minimum of time, and at a reasonable cost.
EDIT: a "gps puck" is a GPS receiver shaped more or less like a hockey puck, like this one
For in-car use there are specific versions that can be fixed onto the vehicle's roof
They are pretty common (many online shops carry them) but select them based on the chip that's inside, the popular Sirf Star 3 is still a solid performer, stable and accurate. I haven't had the chance to play with its successor, the Sirf Star 4 yet, and I'm not implying these are the only good chips around, only that I got most experience with this chip.
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 a ME undergrad and am designing an implant device that requires programming knowledge. I honestly have no idea how to get started and am looking for advice. Basically what I need is a way to control a stepper motor. Stepper motor's use steps (pulses) to rotate the gear head. Now this motor I'm using needs 20 steps to revolve once. I need to be able to control the # of steps I want in a day per say. The motor I'm purchasing comes with an encoder which I'm guessing connects to the circuit board. Now what I want to do is have an external control (like a remote control for a toy)that can set these rates. I don't know anything about radio transmitters, or how to program the circuit board to do this for me. Any help would be appreciated, or books I can look into, websites, or tutorials. Thanks.
There are many ways of solving this problem, but it is more of a systems engineering question than a programming question; until you know what the system looks like, there is no way of determining what parts will be implemented in software. More details would be required to provide a specific answer.
For example what are the security/safety considerations?
What wireless technology do you need to use? e.g. RF or IR, if RF then licensing may be an issue, and that may vary from country to country. You could use BlueTooth, ZigBee, or even WiFi, but these technologies are probably more expensive and complex than necessary for such a simple application. If IR then is immunity from interference from TV remotes or PC IrDA ports or similar required?
If the commands/signals from the remote are complex you will probably need both the remote and the motor driver to incorporate a micro-controller and software. On the other hand if you just need increase/decrease functions then it would be entirely possible to implement the remote functionality you describe without any processing at all (depending on teh communication technology you choose).
What is the motor encoder for? Stepper motors do not normally need an encoder since the controller can simply count steps executed in either direction to determine position. Is the encoder incremental or absolute? If it is incremental, then it is certainly not needed; if it is absolute than it may be useful if you need to know the exact position of the motor on power-up without having to perform an initialisation or requiring end-stop switches.
You mentioned a "circuit board"; what hardware do you already have? What does it do? Do you have documentation for it? If it is commercially available, can you provide a link so we can see the documentation?
As you can see you have more system-level design issues to solve before you even consider software implementation, so the question is not yet ready to be answered here on SO. I suggest you seek out your university's EE department and team-up with someone with electronics expertise do design a complete system, then consider the software aspects.
Well worth taking a look at the Microchip site:
http://www.microchip.com/forums/f170.aspx
They produce microcontrollers that can be programmed to do exactly what you require (and a lot more).
I'd like to start messing around programming and building something with an Arduino board, but I can't think of any great ideas on what to build. Do you have any suggestions?
I show kids, who have never programmed, or done any electronics before, to make a simple 'Phototrope', a light sensitive robot, in about a day. It costs under £30 (GBP) including Arduino, electronics and off-the-shelf mechanics. If folks really get into mobile robots, the initial project can grow and grow (which I feel is part of the fun).
There are international robot competitions which require relatively simple mechanics to get started, e.g. in the UK http://www.tic.ac.uk/micromouse/toh.asp
Ultimate performance require specially built machines (for lightness) , but folks would get creditable results with an Arduino Nano, the right electronics, and a couple of good motors.
A line following robot is the classic mobile robot project. The track can be as simple as electrical tape. Pololu have some fun videos about their near-Arduino 3PI robot. The sensors are about £1, and there are a bunch of simple motor+gearbox kits from lots of places for under £10. Add a few £ for motor control, and you have autonomous robot mechanics, in need of programming! Add an Infrared Remote receiver (about £1), and you can drive it around using your TV remote. Add a small solar cell, use an Arduino analogue input to measure voltage, and it can find the sun. With a bit more electronics, it can 'feed' itself. And so it gets more sophisticated. Each step might be no more than a few hours to a few days effort, and you'll find new problems to solve and learn from.
IMHO, the most interesting (low-cost) competitions are maze solving robots. The international competition rule require the robot to explore a walled maze, usually using Infrared sensors, and calculate their optimal route. The challenges include keeping track of current position to near-millimeter accuracy, dealing with real world's unpredictably noisy environment and optimising straight-line speed with shortest distance cornering.
All that in 16K of program, and 1K RAM, with real-time interrupt handling (as much as 100K interrupts/second for some motor systems), sensor sampling, motor speed control, and maze solving is an interesting programming challenge. (You might make it 'easy' with 32K of program, and 2K RAM :-)
I'm working on a 'constrained' robot challenge (based on Arduino) so that robot performance is mainly about programming rather than having a big budget.
Start small and build up to something more complex. Control servos. Blink LEDs. Debounce inputs. Read analog sensors. Display text on an LCD. Then put it together.
Despite the name, I like the "Evil Genius" book for PIC microcontrollers because of the small, easily digestible projects that tend to build on one another. It is, of course, aimed at PIC programmers rather than the Arduino, but the material covered will be useful no matter what you're developing on.
I know Arduino is trendy right now, but I also like the Teensy++ development board because of its low price-point ($24), breadboard-compatible PCB, relatively high pin count, Linux development environment, USB connectivity, and not needing a programmer. Worth considering for smaller projects.
If you come up with something cool, let me know. I need an excuse to do something fun :)
Bicycle-related ideas:
theft alarm (perhaps with radio link to a base station which is connected to a PC by Ethernet)
fancy trip computer (with reed switch or opto sensor on wheel)
integrate with a GPS telematics unit (trip logging) with Ethernet/USB download of logged data to PC. Also has an interesting PC programming component--integrate with Google Maps.
Other ideas:
Clock with automatic time sync from:
GPS receiver
FM radio signal with embedded RDS data with CT code
Digital radio (DAB+)
Mobile phone tower (would it require a subscription and SIM card for this receive-only operation?)
NTP server via:
Ethernet
WiFi
ZigBee (with a ZigBee coordinator that gets its time from e.g. Ethernet or GPS)
Mains electricity smart meter via ZigBee (I'm interested now that smart meters are being introduced in Victoria, Australia; not sure if the smart meters broadcast the time info though, and whether it requires authentication)
Metronome
Instrument tuner
This reverse-geocache puzzle box was an awesome Arduino project. You could take this to the next step, e.g. have a reverse-geocache box that gives out a clue only at a specific location, and then using physical clues found at that location coupled with the next clue from the box, determine where to go for the next step.
You could do one of the firefighting robot competitions. We built a robot in university for my bachelor's final project, but didn't have time to enter the competition. Plus the robot needed some polish anyway... :)
Video here.
Mind you, this was done with a Motorola HC12 and a C compiler, and most components outside the microcontroller board were made from scratch, so it took longer than it should. Should be much easier with prefab components.
Path finding/obstacle navigation is typically a good project to start with. If you want something practical, take a look at how iRobot vacuums the floor and come up with a better scheme.
Depends on your background and if you want practical or cool. On the practical side, a remote control could be a simple starting point. It's got buttons and lights but isn't too demanding.
For a cool project maybe a Simon-style memory game or anything with lights & noises (thinking theremin-style).
I don't have suggestions or perhaps something like a line follower robot. I could help you with some links for inspiration
Arduino tutorials
Top 40 Arduino Projects of the Web
20 Unbelievable Arduino Projects
I'm currently developing plans to automate my 30 year old model train layout.
A POV device could be fun to build (just google for POV Arduino). POV means persistence of vision.