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1500 questions
40
votes
6 answers
Is analog signal arithmetic faster than digital one?
Would it be theoretically possible to speed up modern processors if one would use analog signal arithmetic (at the cost of accuracy and precision) instead of digital FPUs (CPU -> DAC -> analog FPU -> ADC -> CPU)?
Is analog signal division possible…
zduny
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40
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8 answers
Why do microcontrollers have so little RAM?
Maybe this is more of a perceptional problem, but it seems like microcontrollers have advanced by leaps and bounds in the last 20 years, in almost all regards, higher clock speed, more peripherals, easier debugging, 32-bit cores, etc...
It is still…
Grady Player
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40
votes
6 answers
Why do resistors still use color coding?
I always wondered why color coding is still used on resistors in 2014.
Here is Wikipedia's word on the original reason why :
Colorbands were commonly used (especially on resistors) because they
were easily printed on tiny components, decreasing…
DylanM
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40
votes
14 answers
How can I measure the RPM of a Frisbee?
I'd like to make a little device I can stick onto a Frisbee that could measure stats such as RPM/speed of the Frisbee when thrown. Would this be realistically possible?
I was looking into near-field communication to transfer the data from the…
Barodapride
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40
votes
5 answers
What is an FPGA?
I've seen a lot of people talking about FPGA's before and I know that it stands for field-programmable gate array but how does it work and what is the purpose of using an FPGA?
zklapow
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40
votes
3 answers
What's a schematic (compared to other diagrams)?
What's the difference between a schematic, a block diagram, a wiring diagram and a PCB layout?
Why do engineers want a schematic instead of a wiring diagram?
Where does Fritzing fit into this?
JYelton
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39
votes
13 answers
ARM Cortex-M3 development tools?
I am planning to migrate to the NXP Cortex M3 architecture and I'm a little lost between the existant development tools.
Keil is expensive and I don't know if it's worth it.
Anyone who has tried some compiler can give any advice?
I found this…
mba7
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39
votes
2 answers
Can anyone explain this high-frequency "alien voodoo black magic"?
I was casually watching Mike tear down a spectrum analyser (13:30 is the relevant part, 16:50 is the awesome part), and he came across what he aptly described as "weird messed up alien voodoo black magic stuff":
As a layman, I can only nod in…
Polynomial
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39
votes
4 answers
How do transposition towers in transmission lines work?
There're such things as transposition towers in power distribution powerlines. The idea is that for example you have three conductors running in parallel at the same height and the leftmost of them is phase A and after transposition the middle one…
sharptooth
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39
votes
2 answers
Purpose of "wave shaped" PCB traces
On some PCB designs, specific traces are routed in curious ways. This probably has to do with high frequency design considerations and general signal behavior that I am not familiar with.
Let's take this PCB (somewhere from the web) as an example.…
Rev
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39
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2 answers
What's the difference between INPUT and INPUT_PULLUP?
On newer Arduinos, one can set pinMode to one of three states: OUTPUT,INPUT, and INPUT_PULLUP.
This page says:
The Atmega chip on the Arduino has internal pull-up resistors (resistors that connect to power internally) that you can access. If you…
Manishearth
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39
votes
11 answers
Stranded vs solid wire
What are the advantages of stranded vs solid wire?
what should i be using for prototyping circuits?
SaM
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39
votes
4 answers
How can a 9mm square antenna pick up GPS?
I'm confused again. Per various antenna dipole calculators online, and if GPS uses 1.575 and 1.228 GHz signals, the dipole antenna needs to be on the order of 10 cm. Yet Adafruit has (or had) tiny GPS antennas of about 9mm square. And there's the…
user3303210
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39
votes
7 answers
Why is an inductor not a good antenna?
[An antenna must have] current flowing along its length, so that the resulting fields radiate that energy into space. (Receiving antennas are just this process in reverse).
[This] explains why you can't just stick a small tank circuit on a board…
Phil Frost
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39
votes
9 answers
Parts shortage, no stock, what now? (canonical reference question)
As a small business, student, or hobbyist, sometimes the parts I need are unavailable (no stock anywhere). Maybe authorized distributor will take order but they will not ship for 10, 20, 30 weeks, which is a very long time to wait. If I search on…
MarkU
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