I want to know what sensitivity I am working with on an mpu 9150 (+ Raspberry PI).
this is the library I am using: linux-mpu9150
mpu 9150 page
I want the accelerometer to have more sensitivity(so I must set it to 2+/-g ?!?).
When I count the steps, there aren't enough...I take 10 steps, I count 3-5 steps with matlab (with peakfinds or counting zero crossing)
Example:
Accelerometer at my foot, or at my shin (make similar output)
The github link you posted contains a calibration section, they suggest using imucal here:
https://github.com/mrbichel/linux-mpu9150/blob/master/README.md
Good luck.
Related
I am trying to read the MCU_ID (device electronic signature) from STM32L476 chip using a JTAG ST-Link/V2 on Windows 7. No code has to be uploaded inside the chip, the program shall just be launched on my cumputer and read this information from the flash memory.
I have managed to find and extract the following screenshot from the Reference Manuel given on ST website :
So I have to read the value stored in the flash memory at the adess 0x1FFF7590 by using a C program. I am using the Atollic TrueStudio IDE which is recommended by ST itself, but it seems to me that it includes the "stm32l476xx.h"library which does not even contain any function which could help me.
What I have done so far
After spending days and days looking for some functions or examples to do something as simple as read flash memory, I have asked on this very site How to interact with a STM32 chip memory, which helped me understand a couple of things about what I had to do; nevertheless, I haven't been able to find what I was looking for even after days reading all the links and docs advised in the comments.
I have asked a couple of professionals who told me that I should search for a JTAG driver to interact with the flash memory, but it seems a bit complicated and I haven't been able to found any.
Someone on this site told me that simply using pointer should be enough; the lack of C example and internet tutorials couldn't help me figure out how to do so.
Finally, I started recently digging around STM32Cube and HAL, even since I wanted to avoid using those because I thought that a simple read could be done without having to include those layers. Asking this question is my final hope before trying to use them.
In Conclusion :
I can't show any code since the only thing I have so far is a #include "stm32l476xx.h"and an empty main.
A hint or solution on How to read a STM32L476's flash memory in C would be just perfect. Every example of C (or any programming language which would be as low or higher level) program or instructions interacting with a STM32 chip's memory could help me a lot since it is very hard to find on internet.
Reading MCU ID using ST-Link (graphical interface)
You can use ST-Link Utility (can be downloaded from ST.com here: http://www.st.com/en/embedded-software/stsw-link004.html). After you do Target->Connect you can specify the address and number of bytes you want to read on top of the Window. This also works for the memory area where MCU ID is defined.
For STM32L476 MCU that you use it's going to be memory address 0x1FFF7590, size 0xC (96 bits). Pressing enter should allow you to see the unique ID read from the MCU you're connected to, in form of 3x32 bit values.
Reading MCU ID using ST-Link (command line interface)
ST-Link Utility provides CLI (command line interface) to do the most common operations. This is done using ST-LINK_CLI.exe located in your ST-Link Utility installation directory.
Reading Unique ID as 32-bit values (STM32L476 MCU from the example):
ST-LINK_CLI.exe -r32 0x1FFF7590 0xC
Reading as 8-bit values:
ST-LINK_CLI.exe -r8 0x1FFF7590 0xC
You can also read it to file using -Dump parameter:
ST-LINK_CLI.exe -Dump 0x1FFF7590 0xC D:\temp\out.bin
Keep in mind that you must have the priviledges to write to the destination directory. If you don't run the command prompt with administrative priviledges, in most common cases this means that you won't be able to create the file in locations such as root drive directory (C:\out.bin) or inside "Program Files", where most likely your program is installed (for example by specifying a relative path, such as giving an output file name only out.bin). The program sadly doesn't inform about failed attempts to write the file, however it does say when it succeeds to create the file. The program execution should end with a green line saying Dumping memory to D:\temp\out.bin succeded. In addition, keep in mind that only the following file extensions are supported: *.bin *.hex *.srec *.s19. It cannot be anything because the extension determines the format in which the data will be written to the file.
You can find more information about CLI parameters in User Manual UM0892.
Reading MCU ID using C code
The same can be done using a program loaded into the MCU. You read it by simply accessing the memory directly. Sample code:
#define STM32_UNIQUEID_ADDR 0x1FFF7590
uint32_t id[3];
id[0] = *(STM32_UNIQUEID_ADDR + 0);
id[1] = *(STM32_UNIQUEID_ADDR + 1);
id[2] = *(STM32_UNIQUEID_ADDR + 2);
After this operation id array should contain the same 3x32bit values you've previously read using ST-Link Utility. You may of course choose to read it as uint8_t byte array of size 12, you may even choose to read it into a struct, in case you're interested in the details (lot number, wafer number etc.). This example should however give you a general idea of how to access this value.
There is Texane stlink, that does what you want. It's written in C, interacts with STM32 chips through an ST-Link adapter, and it can read from chip memory.
What you are looking for is not a feature of ST but a feature of ARM.
Remember, ST simply uses an ARM core. I know most programmers load some code in RAM and use that to access flash. You can find these simple programs in the install directory or Keil for example.
I think this is the manual you will need. But I don't know if there is more information behind the login-wall.
being part of a lab course, I have to update the simulation about Pulse Coded Modulation. Initially, the simulation was written in 1998 using the OSS (open sound system) and was never updated thereafter. I have rewritten the entire code and ported it to ALSA.
The code itself is a bit long, that's why I haven't put it here but am providing a link.
Now to my issue: Whenever I want to play a vector of random length containing many samples, I start hearing weird periodic random noises. I have a feeling it's due to a buffer underrun. For a better understanding, I have recorded the output.
I believe it has to do something with the parameters I've set. Even though I tried out many cases, I didn't come to a solution.
Just take a look at the period size, buffer size, periods and the sbplay(..) function. PS.: My HW is set such that buffer size = period size * periods
I hope you can help me somehow! Thanks in advance
Code
Output WAV
BTW.: ALSA: buffer underrun on snd_pcm_writei call
didn't help me much...
Efe,
Why don't you try the audioplayer/audiorecorder functions in MATLAB. They use ALSO on Linux. If you want greater control over the latency try the dsp.AudioPlayer/AudioRecorder system objects.
Dinesh
I'm working on a program that shows the percentage of every process running on a machine with Linux. The problem is that the percentage I get often differs from the one displayed by the top command.
I searched for many hours on the web but what I find is almost always the same formula
100 * (stime + utime)/ (totalCPUTime - processStartTime).
I get the totalCPUTime summing the 7 CPU values in /proc/stat , while stime, utime and processStartTime are values taken form /proc/<pid>/stat.
Am I doing something wrong?
Does the fact that I am running the program on a multicore machine affect somehow the result?
Does somone know how the top calculates this value?
Thank you
If you want to know what top does you should have a look in the source code :)
top.c cvs repository
procps Homepage
My question is slightly abstract but with good grounds. I have successfully ran a JACK script written in C that loops the microphone audio data to the speaker, However I would like to know how to alter the stream of audio my self during playback, perhaps one thing I'd like to try is filter the high(or low) frequencies (CUT them completely off). From my understanding audio comes through as an analog signal and converted to a digital value (within a certain range).
I'm guessing I'm forced to go about this one of two ways, I think one way is to process each value and check if it below the frequency (or above the frequency) I don't want and then alter the value to 0(or the previous value from the last loop cycle to prevent blank spots in the audio during playback). The second way i'm guessing is that JACK presents the buffer with a full array of values that are assigned by frequency spectrum. How do I go about doing this? (In the future I want to do other things with the raw data but I think this is a great start to get familiar with raw audio processing)
Here is my simplified code: http://pastebin.com/Hmiumqkz
You can see that I tried printing the in value as its supposed to be a "float" I thought I might be able to filter frequencies from there but I'm not sure as I don't get anything printed in the console when i run this code it just loops back the mic to speaker but with out any printing to the console.....
NOTES: I have already successfully compiled and tested programs that used the Gstreamer, ALSA, NAudio, irrKang, and the Phonon libraries, they don't allow me to have the cross compatibility i need between OSs and the raw audio data I require for my project, all i ask is to please think twice before lazily report for me to use "other libraries" only for the sake of it being "easier" but I have already tried them and they all fail me.
You haven't really asked a question that can be answered here on SO, so I'll point you to some outside resources.
Here is a tutorial for designing EQs based on the popular RBJ filters:
http://blog.bjornroche.com/2012/08/basic-audio-eqs.html
Most of it is written in C-like psuedocode and will walk you through step-by-step.
Here is the correct answer (You'll notice a printf() function in the proccess(){} call back function) the for loop prints out the the current frames in the buffer(Frequency domain but the for() loop is printing over time so its the time-domain as well -- its both frequency and time)
http://pastebin.com/axDLw7cc
I'm new to LabVIEW but have been building a signal analyser code that takes the required data and prints it out to text files after the data has been taken. The problem I'm having is that when it makes a new file it holds on to the data from the previous run and prints that too which is not what I want. I've attached the LabVIEW vi (ver.2009), and any help with this would be greatly appreciated.
Also if someone knows a better way of RMS-ing the data after each iteration than my mess of shift registers I'd be happy to see it.
frequency analyser (fixed).vi
To answer your main question: the part of the code that builds the string (for loop with a shift register) stores the previous data each time you re-run the vi. What you need is to initialise the shift register with an empty string :
Also a couple of notes/suggestions:
You could avoid using shift registers in this case. Divide the DAQ part of the code into say 3 parts: acquire data in the first for loop (store into array), modify the array (you could then perhaps use the build-in RMS vi), visualise on the UI
Build the code in smaller chunks, use subVi's
Keep the code small, nice and tidy (check coding standards), add comments - this will really help you later
Since you asked for advice on the RMS functionality you used I took a more detailed look of your code. And I may be harse, but it doesn't make sense (point by point):
You ask the end user for a number of runs, and then you subtract one. Why? I guess it's because the read data before the for loop. (remove that one).
The Frequency RMS function you use has support for avaraging, and has no limit of the number of averages. Specify the following configuration:
This will add RMS avaraging to you output data, and you can loose all your own calculation with shift registers.
The following code is just plain wrong:
You only shift the data, without actually changing the data. By incrementing the starting frequency you shift the FFT. So a signal that was detected at 55 Hz, no is plotted at 56 Hz. To your end user this is misleading.
One thing you need to be aware of in your code is that you don't have continious sampling. Each iteration of you for loop your data acquisition is started and stopped. You can verify this by plotting the t0's of the waveform that is captured. You'll notice they don't start at a constant interval.
A better aproach is to use the task created by the Express VI in the first iteration:
.
However you should then change the acquisition mode to 'continious samples':
Do not forget to close the task in the last iteration:
Instead of the shift register, you should work with an array which you empty before each run.