I have a SIM900 and Arduino Leonardo. using the SIM900.h library I have it all working and receiving text messages, etc however I'm wondering how I can use it to either grab all the local tower information or grab the same and triangulate the LAT, LONG, ETC from that information.
You can get information about the local tower (and for a few neighboring towers) with the AT+CENG=2 command. This include things like tower ID and signal level. You'll need to know the geographic location of these towers and do the triangulation yourself.
I suggest you take a look at this project: http://www.open-electronics.org/mini-gsm-localizer-without-gps/. It has an open-source firmware that you may find useful.
Here’s sequence of AT commands needed to get location of module:
AT+SAPBR=3,1,"CONTYPE","GPRS" // set bearer parameter
OK
AT+SAPBR=3,1,"APN","internet" // set apn
OK
AT+SAPBR=1,1 // activate bearer context
OK
AT+SAPBR=2,1 // get context ip address
+SAPBR: 1,1,"10.151.43.104"
OK
AT+CIPGSMLOC=1,1 // triangulate
+CIPGSMLOC: 0,19.667806,49.978185,2014/03/20,14:12:27
OK
Location is not acurrate though, first test got me coordinates located around 4 kilometers away from my place. Usually it’s not that bad, enough for simple applications.
you can use AT+COPS? command to reach location of tower. the 4-digit number expresses the location. for decode the number yıu should use LAC.
i.e +CGREG: 1, A9F0, 200D6E
(the second term A9F0 is the location number of tower)
Related
Using pyiron, I want to calculate the mean square displacement of the ions in my system. How do I see the total displacement (i.e. not folded back by periodic boundary conditions) without dumping very frequently and checking when an atom passes over the boundary and gets wrapped?
Try to compare job['output/generic/unwrapped_positions'][-1] and job.structure.positions+job.output.total_displacements[-1]. If they deliver the same values, it's definitely fine both ways. If not, you can post the relevant lines in your notebook here.
I'd like to add a few comments to Jan's answer:
While job['output/generic/unwrapped_positions'] returns the unwrapped positions parsed from the output files, job.output.total_displacements returns the displacement of atoms calculated from each pair of consecutive snapshots. So if an atom moves more than half the box length in any direction, job.output.total_displacements will give wrong coordinates. Therefore, job['output/generic/unwrapped_positions'] is generally more trustworthy, but it is not available in all the codes (since some codes simply do not provide an output for unwrapped positions).
Moreover, if an interactive job is used, it is possible that job.structure.positions does not return the initial positions, i.e. job.structure.positions+job.output.total_displacements won't be initial positions + displacements.
So, in short, my answer to your question would be rather "Use job['output/generic/unwrapped_positions'] and if it's not available, use job.structure.positions+job.output.total_displacements but be aware of potential problems you might be running into."
How can I simulate continuous traffic flow from historical data which consists of:
1. Vehicle ID;
2. Speed;
3. Coordinates
without knowing the routes of each vehicle ID.
This is a commonly asked questions but probably hasn't been answered here before. Unfortunately the answer largely depends on the quality of your input data mainly on the frequency / distance of your location updates (it would be also helpful if there is a time stamp to each datum) and how precise the locations fit your street network. In the best case there is a location update on each edge of the route in the street network and you can simply read off the route by mapping the location to the street. This mapping can be done using the python sumolib coming with sumo:
import sumolib
net = sumolib.net.readNet("myNet.net.xml")
route = []
radius = 1
for x, y in coordinates:
minDist, minEdge = min([(dist, edge) for edge, dist in net.getNeighboringEdges(x_coordinate, y_coordinate, radius)])
if len(route) == 0 or route[-1] != minEdge.getID():
route.append(minEdge.getID())
See also http://sumo.dlr.de/wiki/Tools/Sumolib#locate_nearby_edges_based_on_the_geo-coordinate for additional geo conversion.
This will fail when there is an edge in the route which did not get hit by a data point or if you have a mismatch (for instance matching an edge which goes in the "wrong" direction). In the former case you can easily repair the route using sumo's duarouter.
> duarouter -n myNet.net.xml -r myRoutesWithGaps.rou.xml -o myRepairedRoutes.rou.xml --repair
The latter case is considerably harder both to detect and to repair because it largely depends on your definition of a wrong edge. There are almost clear cases like hitting suddenly the opposite direction (which still can happen in real traffic) and a lot of small detours which are hard to decide and deserve a separate answer.
Since you are asking for continuous input you may also be interested in doing this live with TraCI and in this FAQ on constant input flow.
I am writing a code to measure the power usage of an NVIDIA Tesla K20 GPU (Kepler architecture) periodically using the NVML API.
Variables:
nvmlReturn_t result;
nvmlEnableState_t pmmode;
nvmlDevice_t nvmlDeviceID;
unsigned int powerInt;
Basic code:
result = nvmlDeviceGetPowerManagementMode(nvmlDeviceID, &pmmode);
if (pmmode == NVML_FEATURE_ENABLED) {
result = nvmlDeviceGetPowerUsage(nvmlDeviceID, &powerInt);
}
My issue is that nvmlDeviceGetPowerManagementMode is always returning NVML_ERROR_INVALID_ARGUMENT. I checked this.
The NVML API Documentation says that NVML_ERROR_INVALID_ARGUMENT is returned when either nvmlDeviceID is invalid or pmmode is NULL.
nvmlDeviceID is definitely valid because I am able to query its properties which match with my GPU. But I don't see why I should set the value of pmmode to anything, because the documentation says that it is a Reference in which to return the current power management mode. For the record, I tried assigning an enable value to it, but the result was still the same.
I am clearly doing something wrong because other users of the system have written their own libraries using this function, and they face no problem. I am unable to contact them. What should I fix to get this function to work correctly?
The problem here was not directly in the API call - it was in the rest of the code - but the answer might be useful to others. Before attempting this solution, one must know for a fact that Power Management mode is enabled (check with nvidia-smi -q -d POWER).
In case of the invalid argument error, it is very likely that the problem lies with the nvmlDeviceID. I said I was able to query the device properties and at the time I was sure it was right, but be aware of any API calls that modify the nvmlDeviceID value later on.
For example, in this case, the following API call had some_variable as an invalid index, so nvmlDeviceID became invalid.
nvmlDeviceGetHandleByIndex(some_variable, &nvmlDeviceID);
It had to be changed to:
nvmlDeviceGetHandleByIndex(0, &nvmlDeviceID);
So the solution is to either remove all API calls that change or invalidate the value of nvmlDeviceID, or at least to ensure that any existing API call in the code does not modify the value.
I have the following code snippet:
#include "contiki.h"
#include <stdio.h> /* For printf() */
PROCESS(calc_process, "calc process");
AUTOSTART_PROCESSES(&calc_process);
PROCESS_THREAD(calc_process, ev, data)
{
double dec=13.2, res=0, div=3.2;
PROCESS_BEGIN();
res=dec+div;
printf("%f",res);
PROCESS_END();
}
After uploading the above code in Tmote sky platform using the command
make TARGET=sky calc.upload, the program will be loaded to the mote (there is no error). Then login to the mote using make login TARGET=sky, the following output is displayed....
OUPUT:
**Rime started with address 4.0
MAC 04:00:00:00:00:00:00:00 Contiki 2.7 started. Node id is set to 4.
CSMA ContikiMAC, channel check rate 8 Hz, radio channel 26
Starting 'calc process'
%f**
How can I get the correct value?
Thanks
It is not floating point calculation support that you need - you have that already. What is missing is floating point support within printf(). That is to say that res will be calculated correctly, but printf() does not support its display.
Because it requires a relatively large amount of code, many microcontroller targeted libraries omit floating point support in stdio. There may be a library build option to include floating point support - refer to the library documentation.
You might do well to ask a question about the specific calculation necessary, and how it might be done using integer or fixed point arithmetic. Alternatively you might write your own floating point display as described here: How to print floating point value using putchar? for example.
I have an array and a variable declared like this
NextPacketRegister : array (1 .. Natural (Size)) of Unsigned_32;
PacketBufferPointer : Unsigned_32;
for PacketBufferPointer'Address use To_Address (SPW_PORT_0_OUT_REG_ADDR);
for NextPacketRegister'Address use To_Address (16#A000_0000# + Integer_Address (PacketBufferPointer));
PacketBufferPointer points to an HW registers that you access thru the PCI of our board.
NextPacketRegister uses this register's value + 16#A000_0000#
The thing is everytime I access NextPacketRegister, behind the scene I perform a PCI access, these access are very slow and we are trying to remove this limitation.
But I can't seem to find a way to modify NextPacketRegister'Address during runtime (I'd like to read ONCE the PacketBufferPointer register and then add this value + 16#A000_0000# only once so I don't have to perform PCI access everytime.
I looked around but I have no clue how I could achieve this.
That is correct; if you use for ...'address use to overlay an object at a specific address, you cannot change it later.
Generally I try to avoid overlays. What you show is one drawback to them. Another is that if the object has any parts that require initialization, they will be reinitialized every time the object is elaborated.
One thing I do have to ask up front though: This looks like a device driver. If you don't like the hit from going to the PCI bus then, fine. The obvious way around your problem of course is to just read the object into a temporary variable and use that when you don't want to hit the PCI bus. But obviously when you do that you are no longer reading directly from the device, and thus won't see changes it made to its memory-mapped registers (and your changes won't go straight to those memory-mapped registers). That's what you want, right? Ada contains no magic to allow you to get data on and off the PCI bus without hitting the PCI bus.
It almost looks like you are thinking that this line:
for NextPacketRegister'Address use To_Address (16#A000_0000# + Integer_Address (PacketBufferPointer));
Means: "Every time I access NextPacketRegister, go find the value of PacketBufferPointer and overlay it where it happens to be right now". That is not the case. This will only happen once when your declaration is processed. Thereafter, every access to something like NextPacketRegister[12] will go to the same place, without any access to PacketBufferPointer.
Another way would be to use pointers and Unchecked_Conversion. That's generally my preferred solution for overlays. It looks hairer, but what you are doing is hairy, so it should look that way. Also, it doesn't perform initializations on the overlaid memory area. I suppose that could be a bad thing though, if you count on those. Of course overlaying this way could cause an access to PacketBufferPointer, if you want. You'd have control over it depending on how you code it.
Since you asked about pointers, in this case I think you have a very valid case for using the package System.Address_to_Access_Conversions. I don't have the compiler handy, but I think it would go something like this:
type Next_Packet_Array is array (1 .. Natural (Size)) of Unsigned_32;
package Next_Packet_Array_Convert is new System.Address_To_Access_Conversions
(Next_Packet_Array);
Synced_Next_Packet_Address : System.Address;
Now when you "sync", I guess you'd want to hit that PacketBufferPointer to get the register value (as a SYSTEM.ADDRESS), and save it into a variable for later use:
Synced_Next_Packet_Address = 16#A000_0000# + Integer_Address (PacketBufferPointer);
And when you want to access the Next_Packet_Array, it would be something like this: Next_Packet_Array_Convert.To_Pointer (Synced_Next_Packet_Address).all
Make a structure (array of buffers ? ) that is what your set of packet buffers looks like and sit that at the address of the start of the array.
read the array index from the register.
you can write C in any language, even Ada.
At least it works and you get some sensible bounds checks.