I have very little experience with ECE in general and I am delving into using an Arduino for some small hobby type projects.
I was following an online guide, and the person who wrote says that I need:
"2 - 1N5227 or similar 3.6V biased zener diodes"
I have read up a bit on Zener Diodes and now understand what they do and what their purpose is. I am not able to tell what he means by similar in this context though. I purchased a Diode Kit that includes 4 types of Zener Diodes. They all have different part numbers and voltages.
The 4 I have are:
1N751 5.1V
1N4733 5.1V
1N4735 6.2V
1N4742 12V
Would any of those be usable in this context or should I order the specific model he states?
The guide being referenced is this, if it is helpful: http://www.instructables.com/id/RC-Transmitter-to-USB-Gamepad-Using-Arduino/
I really appreciate the time and assistance with this, this is a fun area to learn in!
In electronics and other engineering areas, similar refers to the property that stands out (in this case the voltage), in your case refers to looking for another zener diode whose voltage is similar to the example. As I see none of those diodes replaces the example.
Zener diodes has two parameters you need to match in the selection of a replacement (independently the manufacturer):
The Zener voltage (Vz) and the diode power.
For your application you will need a Zener diode of 3.6 V, and usually with 1/4 W to 1/2 W (depending the application power you will need) it will be enough.
You need also to calculate the limiting resistor for the Zener diode.
I recommend you to read the book of Albert Paul Malvino or similar to better understand.
Regards.
Related
I try to understand and implement modifications to the Veins framework. Right now, I have some difficulties figuring out how the "Mapping" structure works. It is used to set the transmission power in "Mac1609_4.cc"
ConstMapping* txPowerMapping = createSingleFrequencyMapping(start, end, frequency, 5.0e6, power)
and to calculate received power, SNR and SINR in "Decider80211p.cc". Could you give some insight and some examples related to the structure manipulation?
The mapping structure is from MiXiM, as Veins initially forked that project. MiXiM, however, is deprecated now and should not be used anymore [2]. Unfortunately, there is no real documentation available (anymore).
As replacement, there is either INET, which also is supported by Veins, or, as it will be introduced in the next release, a much simpler representation of Signals, removing the Mapping structure [4].
If you still need to understand the structure, you can have a look at this paper where the authors explained the physical layer including the Mapping structure.
I want to learn how to use LogiCORE DSP48 Macro. I'm reading the Xilinx documentation but I cannot understand well how to start my first design with DSP48 Macro. Can anyone help me to make a simple design to get a better understanding of this IP core please?
Thanks in advance!
In many cases you would use DSP48 by writing Verilog/VHDL expressions containing add, subtract, and multiply.
x = a * b + c
A problem with the above expression is that the multiplication and addition take place in a single cycle. You can run the expression at a higher frequency if the operation could be pipelined. Vivado can sometimes retime these expressions across registers in order to make use of the DSP48 pipeline registers.
However, I understand wanting to use the DSP48 directly. You instantiate DSP48's just like other RTL modules. The ports, parameters, and behaviors are described in the DSP Slice User Guide for the FPGA logic that you are using.
wire [47:0] c;
wire [24:0] a;
wire [17:0] b;
DSP48E1#() dsp(
.a(a),
.b(b),
.c(c),
.p(x),
.opmode(5),
.alumode(0)
);
This instance is copied from one of my inner-product implementations. It is fully pipelined because I was aiming for 500MHz operation. Only achieved 400MHz due to other combinational paths.
For Xilinx 7 Series:
DSP48E1 Slice User Guide
For Xilinx Ultrascale:
DSP48E2 Slice User Guide
I'm looking for some guidance on the approach I should take to mapping some points with R.
Earlier this year I went off to a forest to map the spatial distribution of some seedlings. I created a grid—every two meters I set down a flag with a tagname, and what I did is I would measure the distance from a flag to a seedling, as well as the angle using a military compass. I chose this method in hopes of getting better accuracy (GPS Garmins prove useless for this sort of task under canopy cover).
I am really new to spatial distribution work altogether, so I was hoping someone could provide guidance on what R packages I should use.
First step is to create a grid with my reference points (the flags). Second step is to tell R to use a reference point and my directions to mark the location of a seedling. From there come other things, such as cluster analysis.
The largest R package for analysing point pattern data like yours is spatstat which has a very detailed documentation and an accompanying book.
For more specific help you would need to upload (part of) your data so we can see how it is organised and how you should read it in and convert to standard x,y coordinates.
Full disclosure: I'm a co-author of both the package and the book.
I can not understand how the namespace works in ROS http://wiki.ros.org/Names
Can you hang a couple of real examples of how this works?
And the same question on the parameters http://wiki.ros.org/Parameter%20Server
What do these names mean?
Are the names of the package-node-parameter or what?
Namespaces are the best option to deal with name collision which is quite oft in robotics, especially when the system is going bigger and more complex...
Imagine you have a robot with 2 sensors for the distance, the front and back, then you can think I have 2 topics with the same info
distance=10 and distance=10
now what? how can a 3rd node knows which distance is which???
now using namespaces you can avoid that issue by just doing
back/distance=10 and front/distance=10
The RedPitaya is a great looking instrument, but I'm afraid that I'll kill my new (expensive) device by stray voltage or ESD off my bench, within a few days.
Is it planned to make an optional "professional" case or similar to protect it?
Has anyone already created a 3D model so a printable case or housing could be made?
As a quick fix, I would:
use a piece of plain printer paper on the bench, underneath the Red Pitaya (it's typically more conductive than a typical plastic coating on the bench, but still not so cunductive as to short anything on the board bottom), and
more importantly, each time when approaching the bench, first touch the outside of one of the golden SMA jacks.
Probably any quick google search would answer the question but for the sake of completeness, I will answer this quesiton with what I found in my quick search.
Purchase Options
Now a days, there are several cases available for the pitaya:
Available on RS-components, Reichelt, amoung others:
RS Code: RS819-4077
Manufacturer: Red Pitaya
Manufacturer Ref: 1600 0715 001
Approximate cost: 20 Euros + Shipping + taxes
What appears to be 3d printed providers:
Nylon Plastic closed top case : Approximate 30 Euros
Nylon Plastic open top case
Printing Options
If you happen to have your own 3D printer then you can print one of many available designs.
Closed Top case
Open Top case
A Shielded Case Github Prject, on Thingiverse, on Youmagine
Others can be found on http://www.yeggi.com/ , http://grabcad.com/ ,...