I'm using an arduino to excitate and amplify strain gauges on a rod - the resulting voltage will be picked up by the analog inputs available on the arduino. I need to plot the 'torque' taken by that rod with respect to time on a graph, and the easiest way I see to do this is using the Processing language, as the basic arduino environment does not provide for graphical display.
Any tips on where to start? I only have prior experience with MATLAB, and a bit with Java.
EDIT: I should add a specific question - how do I assign a variable in Processing to the physical values read on the arduino (varying voltage through analog)?
Thanks.
Since you have experience with MATLAB, consider using the ArduinoIO API provided by The MathWorks. Basically lets you interface your Arduino to MATLAB - all the pin I/O features are available. So let MATLAB do the work plotting, etc, for you and just use your Arduino to collect your data.
I can personally vouch for how useful this API is. It's powering my master's thesis (building Arduino-powered vehicles and doing control on them).
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I’m a college student and I’m trying to build an underwater robot with my team.
We plan to use stm32 and RPi. We will put our controller on stm32 and high-level algorithm (like path planning, object detection…) on Rpi. The reason we design it this way is that the controller needs to be calculated fast and high-level algorithms need more overhead.
But later I found out there is tons of package on ROS that support IMU and other attitude sensors. Therefore, I assume many people might build their controller on a board that can run ROS such as RPi.
As far as I know, RPi is slower than stm32 and has less port to connect to sensor and motor which makes me think that Rpi is not a desired place to run a controller.
So I’m wondering if I design it all wrong?
Robot application could vary so much, the suitable structure shall be very much according to use case, so it is difficult to have a standard answer, I just share my thoughts for your reference.
In general, I think Linux SBC(e.g. RPi) + MCU Controller(e.g. stm32/esp32) is a good solution for many use cases. I personally use RPi + ESP32 for a few robot designs, the reason is,
Linux is not a good realtime OS, MCU is good at handling time critical tasks, like motor control, IMU filtering;
Some protection mechnism need to be reliable even when central "brain" hang or whole system running into low voltage;
MCU is cheaper, smaller and flexible to distribute to any parts inside robot, it also helps our modularized design thinking;
Many new MCU is actually powerful enough to handle sophisticated tasks and could offload a lot from the central CPU;
I'm interested in starting a hobbyist project, where I do some image processing by interfacing HW and SW. I am quite a newbie to this. I know how to do some basic image processing in Matlab using the existing image processing commands.
I personally enjoy working with HW and wanted to a combination of HW/SW to be able to do this. I've read articles on people using FPGAs and just basic FPGAs/micro-controllers to go about doing this.
Here is my question: can someone recommend languages I should consider that will help me with interfacing on a PC? I image, the SW part would essentially be a GUI and is place-holder for all the processing that is done on the HW. Also in-terms of selecting the HW and realistically considering what I could do on the HW, could I get a few recommendations on that too?
Any recommendations will be appreciated!
EDIT: I read a few of the other posts saying requirements are directly related to knowing what kind of image processing one is doing. Well initially, I want to do finger print recognition. So filtering and locating unique markers in the image etc.
It all depends on what you are familiar with, how you plan on doing the interface between FPGA and PC, and generally the scale of what you want to do. Examples could be:
A fast system could for instance consist of a Xilinx SP605
board, using the PCI Express interface to quickly transfer image
data between PC and FPGA. For this, you'd need to write a device
driver (in C), and a user-space application (I've done this in
C++/Qt).
A more realistic hobbyist system could be a Xilinx SP601
board, using Ethernet to transfer data - you'd then just have to
write a simple protocol (possibly using raw sockets (no TCP/UDP) to
make the FPGA side Ethernet simpler), which can be done in basically
any language offering network access (there's a Xilinx reference
design for the SP605 demonstrating this).
The simplest and cheapest solution would be an FPGA board with a
serial connection - you probably wouldn't be able to do any
"serious" image processing with this, but it should be enough for
very simple proof-of-concept stuff, although the smaller FPGA devices used o these boards typically do not have much on-board memory available.
But again, it all depends on what you actually want to do.
I don't know if this is the right place to ask this question.
I am working on a project in which I have to use ultrasonic sensors only to do "simultaneous localization and mapping" of robot. I have 8 such sensors. Assume that i have enough computation power and the limited sensing(8 ultrasonic sensor) capability.
What would be an appropriate algorithm to use in this case?
I found SLAM for Dummies to be very helpful.
According to your question, the algorithm to use is SLAM.
There are many possible SLAM implementations. http://openslam.org
I have to develop some software in my school to utilize the accelerometer in the Wiimote for recording data from experiments, for example finding the acceleration and velocity of a moving object. I understand how the accelerometer values will be used but I am sort of stuck on the programming front. There is a set of things that I would like to do:
Live streaming of data from the Wiimote via bluetooth
Use the accelerometer values to find velocity and displacment via integration
Plot a set of results
Avoid the use of the infrared sensor on the Wiimote
Please can anyone give me their thoughts on how to go about this. Also it would be great if people could direct me to existing projects that utizlise the wiimote. Also can someone suggest what would be the best programming language to use for this. My current bet is on using Visual basic.
Any sort of help is greatly appretiated.
There's some famous projects using the Wii remote by Johnny Lee Chung.
They use C# and you can download the source.
By and large they are the reverse of what you want - they use the camera, but you should be able to use the source as a starting point and to analyse the data coming from the remote.
NOTE: At the time of writing the Wiimote library linked to is unavailable, but as it's an MSDN site it should be back soon.
Addendum: It looks like this is now available on Codeplex
This also has a link to various applications built on the library. Wii Drum High looks like it just reads the accelerometer.
I have written some software to do some of what you ask. Check out wiiphysics.site88.net.
You will find integrating the acceleration data very tricky to get any decent results.
It is written in c#.
One problem is what are your initial conditions (ok if you start at rest), the other is that by the time you get to displacement you will have a lot of noise (the acceleration data from a wiimote is only 8-bit)
I have a raw grabbed data from spectrometer that was working on wifi (802.11b) channel 6.
(two laptops in ad-hoc ping each other).
I would like to decode this data in matlab.
I see them as complex vector with 4.6 mln of complex samples.
I see their spectrum quite nice. I am looking document a bit less complicated as IEEE 802.11 standard (which I have).
I can share measurement data to other people.
There's now a few solutions around for decoding 802.11 using Software Defined Radio (SDR) techniques. As mentioned in a previous answer there is software that is based on gnuradio - specifically there's gr-ieee802-11 and also 802.11n+. Plus the higher end SDR boards like WARP utilise FPGA based implementations of 802.11. There's also a bunch of implementations of 802.11 for Matlab available e.g. 802.11a.
If your data is really raw then you basically have to build every piece of the signal processing chain in software, which is possible but not really straightforward. Have you checked the relevant wikipedia page? You might use gnuradio instead of starting from scratch.
I have used 802.11 IEEE standard to code and decode data on matlab.
Coding data is an easy task.
Decoding is a bit more sophisticated.
I agree with Stan, it is going to be tough doing everything yourself. you may get some ideas from the projects on CGRAN like :
https://www.cgran.org/wiki/WifiLocalization