Guys I want to ask if possible to create a solar powered automatic bell system with smoke detection using raspberry pi? And I worries if the raspberry pi have real time clock? Because I need a RTC to execute the bell in exact alarm for certain interval I set.
This the statement I find in internet for more details but the author used an arduino.
The system uses the real time clock to determine
the time and the bell rings based on set up time. The LCD
in this system displays current time and displays fire if
the smoke detector detects a smoke. For different
sessions, the bell will ring different numbers of times.
The system is expected to continuously display the time
by using real time clock and monitor the situation of the
school during the day and night with power generated by
solar energy [9]. By using solar energy as a power source,
the system is uninterrupted during power supply failure
from the main energy department. In addition, the energy
can be used efficiently during day time and stored energy
in the battery can be utilized during night time. This
designed bell system integrated with smoke detector
integration is expected to safeguard the institution from
damages and losses particularly during an outbreak of
fire.
Your project is indeed feasible. The RPI check for the smoke detector value at a certain interval of time. If the value is higher than a certain threshold then you ring your bell.
The raspberry pi does not have a RTC included. You'll have to buy one online (a simple research on google should lead you to online shop like adafruit ...). But I don't understand why you would need to use a real time clock. If you want to use this system (which I don't recommend ; use a certified equipment for your personal security) you should check the data from the smoke/fire detector quite regularly but it doesn't have to be matching real time clock.
Alternatively, you could use RPI WiFi/Ethernet to request RTC from the internet.
If you are doing this project just for fun, use a smoke detector and a buzzer. Your RPI should be able to provide enough current to power both of these equipment. You could power your RPI with a small battery or a charger (check the correct voltage & current needed by the RPI).
You should find a lot of information/tutorials/code online for these type of little projects.
Related
My Mobile Is heating up because of continues usage of my application .
For Detecting how well the driver is driving my application Uses These services :-
Accelerometer For starting the trip .
GPS To find the location and speed.
Then Syncing all the data to the server and writing that data to file locally.
After Few minutes my mobile heats up .
I Want to prioritize the services that is heating up my mobile and need to fix this issue of heating up .
Among the three apps you mentioned, GPS is by far the biggest power hog. It can be easily 50 times more than accelerometer. With GPS you are dealing with acquiring the signal in multiple frequencies, and it does a lot of number crunching at every specified epoch which also consumes a lot of power. However, for accelerometer the data is already inside of your mobile device. Thus, no significant power hogging for acquiring the data. I wouldn't worry about the 3rd case since a lot of apps do that with little heating problem.
So start with working on GPS case first.
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 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).
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.
I have an embedded device (Technologic TS-7800) that advertises real-time capabilities, but says nothing about 'hard' or 'soft'. While I wait for a response from the manufacturer, I figured it wouldn't hurt to test the system myself.
What are some established procedures to determine the 'hardness' of a particular device with respect to real time/deterministic behavior (latency and jitter)?
Being at college, I have access to some pretty neat hardware (good oscilloscopes and signal generators), so I don't think I'll run into any issues in terms of testing equipment, just expertise.
With that kind of equipment, it ought to be fairly easy to sync the o-scope to a steady clock, produce a spike each time the real-time system produces an output, an see how much that spike varies from center. The less the variation, the greater the hardness.
To clarify Bob's answer maybe:
Use the signal generator to generate a pulse at some varying frequency.
Random distribution across some range would be best.
use the signal generator (trigger signal) to start the scope.
the RTOS has to respond, do it thing and send an output pulse.
feed the RTOS output into input 2 of the scope.
get the scope to persist/collect mode.
get the scope to start on A , stop on B. if you can.
in an ideal workd, get it to measure the distribution for you. A LeCroy would.
Start with a much slower trace than you would expect. You need to be able to see slow outliers.
You'll be able to see the distribution.
Assuming a normal distribution the SD of the response time variation is the SOFTNESS.
(This won't really happen in practice, but if you don't get outliers it is reasonably useful. )
If there are outliers of large latency, then the RTOS is NOT very hard. Does not meet deadlines well. Unsuitable then it is for hard real time work.
Many RTOS-like things have a good left edge to the curve, sloping down like a 1/f curve.
Thats indicitive of combined jitters. The thing to look out for is spikes of slow response on the right end of the scope. Keep repeating the experiment with faster traces if there are no outliers to get a good image of the slope. Should be good for some speculative conclusion in your paper.
If for your application, say a delta of 1uS is okay, and you measure 0.5us, it's all cool.
Anyway, you can publish the results ( and probably in the publish sense, but certainly on the web.)
Link from this Question to the paper when you've written it.
Hard real-time has more to do with how your software works than the hardware on its own. When asking if something is hard real-time it must be applied to the complete system (Hardware, RTOS and application). This means hard or soft real-time is system design issues.
Under loading exceeding the specification even a hard real-time system will fail (hopefully with proper failure indication) while a soft real-time system with low loading would give hard real-time results. How much processing must happen in time and how much pre/post processing can be performed is the real key to hard/soft real-time.
In some real-time applications some data loss is not a failure it should just be below a certain level, again a system criteria.
You can generate inputs to the board and have a small application count them and check at what level data is going to be lost. But that gives you a rating specific to that system running that application. As soon as you start doing more processing your computational load increases and you now have a different hard real-time limit.
This board will running a bare bones scheduler will give great predictable hard real-time performance for most tasks.
Running a full RTOS with heavy computational load you probably only get soft real-time.
Edit after comment
The most efficient and easiest way I have used to measure my software's performance (assuming you use a schedular) is by using a free running hardware timer on the board and to time stamp my start and end of my cycle. Or if you run a full RTOS time stamp you acquisition and transition. Save your Max time and run a average on the values over a second. If your average is around 50% and you max is within 20% of your average you are OK. If not it is time to refactor your application. As your application grows the cycle time will grow. You can monitor the effect of all your software changes on your cycle time.
Another way is to use a hardware timer generate a cyclical interrupt. If you are in time reset the interrupt. If you miss the deadline you have interrupt handler signal a failure. This however will only give you a warning once your application is taking to long but it rely on hardware and interrupts so you can't miss.
These solutions also eliminate the requirement to hook up a scope to monitor the output since the time information can be displayed in any kind of terminal by a background task. If it is easy to monitor you will monitor it regularly avoiding solving the timing problems at the end but as soon as they are introduced.
Hope this helps
I have the same board here at work. It's a slightly-modified 2.6 Kernel, I believe... not the real-time version.
I don't know that I've read anything in the docs yet that indicates that it is meant for strict RTOS work.
I think that this is not a hard real-time device, since it runs no RTOS.
I understand being geek, but using oscilloscope to test a computer with ethernet/usb/other digital ports and HUGE internal state (RAM) is both ineffective and unreliable.
Instead of watching wave forms, you can connect any PC to the output port and run proper statistical analysis.
The established procedure (if the input signal is analog by nature) is to test system against several characteristic inputs - traditionally spikes, step functions and sine waves of different frequencies - and measure phase shift and variance for each input type. Worst case is then used in specifications of the system.
Again, if you are using standard ports, you can easily generate those on PC. If the input is truly analog, a separate DAC or simply a good sound card would be needed.
Now, that won't say anything about OS being real-time - it could be running vanilla Linux or even Win CE and still produce good and stable results in those tests if hardware is fast enough.
So, you need to simulate heavy and varying loads on processor, memory and all ports, let it heat and eat memory for a few hours, and then repeat tests. If latency stays constant, it's hard real-time. If it doesn't, under any load and input signal type, increase above acceptable limit, it's soft. Otherwise, it's advertisement.
P.S.: Implication is that even for critical systems you don't actually need hard real-time if you have hardware.