Questions tagged [matrix]

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Incorrect results without printing message

I am trying to make a custom tv remote using an ATmeta328p microcontroller. It contains 28 buttons which are wired in a matrix configuration, resulting in 5 outputs (columns) and 6 inputs (rows). ...
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72 views

Why is the coefficient symbol changed?

I'm solving this very basic problem with 3 voltage sources and I have no problem getting to the equations to create the matrix [U=RI], These are: I1-I2-I3 = 0 U1-I1R1-I2R2-U2 = 0 U2+i2R2-I3R3-U3 = 0 ...
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58 views

Detecting magnets regardless of polarity

I'd like to build large matrix of sensors to detect objects placed on it. I can place magnet or metal inside detected pieces. I tried to use reed switch and hall sensors. Hall sensors seems like ...
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2 votes
1 answer
43 views

Replacing a keypad on DYMO LetraTag

I'm rebuilding my label printer to become an Internet service using an ESP8266. It's a fun project, never mind the usefulness. The keypad will be removed and instead my MCU emulates keypresses. The ...
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Nodal Analysis and Matrices for more complex circuits

I would like to know how I should write a matrix equation for a circuit containing dependent sources, diodes, capacitors, and voltage sources. I am familiar with the \$\small G V = I\$ matrix equation ...
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Combining S-parametric Blocks

I would like to ask you, please, how I can combine general S-parametric blocks together. Consider the situation in the following picture. Considering this example, I would like to connect these three ...
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1 vote
2 answers
125 views

Mutual inductive coupling in a nodal admittance matrix

I have this question that has been haunting for quite a while now. To compute the nodal admittance matrix \$Y_N\$ of an electrical network, one can make use of the incidence matrix and the branch (or ...
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58 views

Autocorrelation function of discrete time sequence

Say you have 2 discrete information sources each one being represented by a Gaussian random variable. This is the idea. Say I want to find the correlation of the 2 to know whether they are stationary....
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32 views

Charaterization of waveguide to coaxial adapter

I'm trying a method to characterize a high frequency waveguide to coaxial adapter( 2-port network). For this, I use 3 adapters A1, A2, A3. After a TRM calibration, I measure A1 connected with A2 with ...
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1 answer
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Implement a voltage feedback method to reduce the crosstalkin resistive matrix

I'm new in electronics and i want to develop a resistive matrix that is pressure sensitive. Right now, I have a 7x7 matrix and I'm implementing this using multiplexers, a reference resistor and an ...
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0 votes
1 answer
90 views

Effective resistance from a random resistance network

I am trying to calculate the equivalent resistance from a random resistance network formed by carbon nanotubes (CNTs.) I have a MATLAB program where the CNTs are randomly distributed inside a volume. ...
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1 answer
100 views

RGB LED matrix 64x32 + ESP32 powering

I'm trying to figure out what's the best way to power a 64x32 RGB LED matrix and an ESP32 WROOM 32D using both a power bank (some 18650 2000mAh 3.7V in parallel + voltage regulator) and USB C (5V 3A). ...
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2 answers
499 views

Solving nodal analysis equations using matrices- gives a full rank matrix

I am trying to solve for node voltages in a circuit using nodal analysis. I am using the fact that the sum of the currents into each node must equal 0. I have a system of equations which can be ...
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2 votes
4 answers
143 views

Circuit analysis (Current intensity)

In my electrical engineering lecture we analyse such circuits with given Resistances \$R_i\$ and given \$U_{q1}\$ and \$U_{q2}\$ ( see example below ), and we try to find the current intensity \$I_{i}\...
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3 votes
1 answer
278 views

Pressing one key in a button matrix reads all keys in that column

I'm using an MCP23017 IO Expander to make a button matrix (4x4). ...
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1 answer
64 views

Scattering matrix in microwave amplifier

What exactly is the scattering matrix in a microwave amplifier. I tried to deduce from lectures what it is used for in a microwave amplifier, but all I found were the formulas corresponding to the ...
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1 answer
153 views

ARM CMSIS Matrix conversion to a uint16_t array

I'm working on the STM32L476RG and I'm looking to perform some matrix operations on the controller, using C and CMSIS-DSP for ARM. I have 2 uint16_t arrays which I will be converting to matrices and ...
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2 votes
0 answers
52 views

Using an MCP23008 IC with a 4X4 matrix keypad on a Raspberry Pi [closed]

I want to be able to free up the native GPIO pins on my Raspberry Pi Zero. I know the MCP23008 gives me 8 extra pins, but I can't seem to find any resources on using the additional pins with a 4X4 ...
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39 views

Axis of Euler rotation matrix

I'm searching the way to measure rotational displacement by using Euler rotational matrix. And I could find various information about it. Then I've found something wrong with reference axis. In the ...
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4 answers
151 views

Is it possible to solve for the values of this grid of photoresistors in software?

In this question a circuit was set up as shown: The idea is to power the rows one at a time, and read off the voltages of each column. But there's a subtle problem. There are alternate paths to ...
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1 vote
1 answer
100 views

5v analog switch for 3.3v logic ok?

I have a project where I want to interface with a keyboard matrix / scanner (this is a PCB from a consumer electronics device). There's already an implementation that uses some analog muxes for this, ...
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0 votes
1 answer
36 views

4*4 reverse matrix code in matlab wich has variables

Here is the system of which I have found the state space equation. I need to get the transfer function. [SI-A] is a 4x4 matrix and it's so hard to get the reverse ...
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0 answers
25 views

In the AT42QT1245 touch sensor controller, how do the buttons wire to the device?

Referring to the datasheet wiring diagram, page 4 here: https://www.mouser.com/datasheet/2/268/Atmel-9632-AT42-QT1245_Datasheet-1368898.pdf It simply says "Matrix X Drive" and "Matrix Y ...
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1 vote
5 answers
236 views

Huge analog switching matrix

My application is a PCB that has 2 different 100 pins connectors and has to be capable of arbitrarily connect each pin on the first connector to each pin of the second. The signal going through the ...
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3 votes
1 answer
130 views

How to implement an interconnection matrix in VHDL?

I was reading through the documentation of the AXI standard when I came across the interconnection matrix shown below. In short, the interconnection matrix provides a path for several masters to ...
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0 votes
0 answers
356 views

Resistor Keyboard Vs Matrix Keyboard

I'm part way through my prototye macro keyboard which currently consists of 4 keypads with 16 keys on each - so 64 keys in total. The method I'm using is the 3 wire, resistor based one.R1,R2,R3 and ...
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0 votes
0 answers
36 views

Convert expanded boolean function into a switching matrix

I am given a boolean function f(x) that I have to develop them according certain variables, let's call them a0 and ...
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1 vote
2 answers
100 views

How to control a matrix of electromagnets

I'm trying to design a matrix of electromagnets, but I'm having trouble on figuring out the control schematic. I need to control the 12V 70mA coils using an Arduino Uno (5V 40mA max output). ...
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1 vote
1 answer
133 views

Positive Definitness of Noise Covariance Matrix in Kalman Filter

I am reading a paper on Kalman filter and trying to understand measurement noise covariance and positive definitness of the covariance matrix. It is mentioned in the paper that if the matrix is ...
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0 votes
2 answers
282 views

Is this a valid matrix circuit, I've drawn it based on guides and examples online

I'm trying to build a matrix of 6 toggle switches 6 momentary buttons 4 rotary encoders I'm going to use a Pro Micro board and I'm wondering if my wiring looks okay, this is my first real ...
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1 vote
1 answer
336 views

How to individually control electromagnets in a 16x16 matrix?

I'm looking to be able to individually control each electromagnet in a 16x16 matrix. It's also important to note that I want to control these via an Arduino and maybe eventually a Raspberry pi - ...
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0 votes
2 answers
40 views

Multiplexing cell of matrix

in a project I am developing I have a matrix of cells, each cell containing 3 buttons (it will be more eventually, around 10). The schematic is like this: I want to read each one of the cells, and in ...
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0 votes
1 answer
98 views

Transfer function and graphic (Scilab error)

I'm trying to solve this problem with a Scilab code: I'm trying to follow this code, but in the step [b,a]=ss2tf[A,B,C,D], it shows the error ("Wrong number of ...
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0 votes
1 answer
244 views

Equivalent Circuit of identical transformers connected in parallel or series

I'm trying to figure out how to solve the equivalent circuit for 2 identical transformers connected in series or parallel on the primary and secondary. Mainly I want to know what the equivalent ...
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1 vote
1 answer
72 views

Is there a way to optimize this solution for closing two circuits with one button on a scale?

I am (as a hobby) looking into making a keypad with independently scanned keys. I am going with a row-column matrix approach (due to limited GPIO). And would like to utilize MCUs low power modes. Now ...
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1 vote
1 answer
78 views

Observability matrix different forms

The observability matrix formula is present in two forms in textbooks. My question is about which one to use. the first one: the second one: Now when applying both on the same system, I get ...
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0 votes
1 answer
69 views

LED Matrix design without micro-controller

I am working on a project concerning the creation of a LED matrix (4 x 6) but without using a micro-controller. It will be powered by a 13V battery and the leds will be controlled by a switch. My ...
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0 votes
2 answers
327 views

How to use two Demux to index a matrix layout of registers

Consider the following. Let's say for simplicity sake I have an arrangement of 8 bit registers in a 4x4 matrix layout. I could easily use a Demux that has a 4 bit input select line for the addresses ...
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1 vote
1 answer
58 views

Controlling a 19x19 input matrix

I'm designing a go board that can detect where pieces are placed through a raspberry pi for the purpose of game recording. I'm planning to put magnates on the bottom of pieces and do the detection ...
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0 votes
0 answers
426 views

What will be minimum number of states / state variables for these control systems in state-space model?

Consider the systems as LTI and SISO with transfer functions given below: I have read that minimum number of states for an LTI SISO system required to represent in state space analysis for any ...
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2 votes
0 answers
65 views

Why is any general cutset equation a linear combination of fundamental cutsets?

I have currently started studying circuit theory and my professor introduced graphs to form kvl and kcl equations. When we form the cutset matrix using fundamental cutsets it is easy to understand ...
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0 votes
1 answer
137 views

BCD4511 Seven Segment Display Decoder + Diode Matrix

i'm having some issues trying to get a circuit to work that i have found on, yes, the infamous instructables. It consists of a diode matrix that goes to the inputs of a BCD4511 decoder IC. It's ...
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0 votes
0 answers
134 views

How to convert T matrix to Z matrix in two port network?

How can I transform a T matrix to become a Z matrix for a two-port network? I found the following conversion to get the T matrix from Z matrix from here: Two-Port Parameter Conversions Step 7 - ...
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1 vote
1 answer
183 views

Matrix of small incandescent lightbulbs - problem with buzzing

I am prototyping a circuit for controlling matrix display of small incandescent lamps with Arduino (each lamp is 6.3V 0.3A). I designed the circuit in Yenka and built it. It is composed from 3 types ...
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0 votes
1 answer
326 views

Node analysis with voltage source in matrix form

simulate this circuit – Schematic created using CircuitLab Can you please check if my reasoning is correct? The sum of currents leaving node k is: $$ I_k = \sum_{i = 0}^{n} I_{ki} = \sum_{i = ...
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1 vote
1 answer
2k views

Finding Z-parameters from a two-port network and using them to find S-parameters

So I have the two-port network and I want to find out the Z-parameters of it (and later, use that to find the S-parameters). For the assignment, \$R_x=8Ω\$. From what I understood, I should null ...
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0 votes
0 answers
63 views

s-parameter matrix analysis

So I'm trying to figure out how I can analyze S-parameter matrices. The i. should be pretty straightforward, though I'm not 100% sure if I am correct with what it means. I'm assuming that there's ...
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1 vote
2 answers
131 views

Row Column Matrix Problem with Flyback Diodes

So I had a simple row column matrix which I am driving with mosfets to power solenoid locks like this: GC is ground via 1.5k resistor C is 24V via 1.5k resistor And these are the connectors: ...
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2 answers
115 views

Can I in any way connect +ve side of my led to uln2083a output pin?If no can I do it with M54562 transistor array?

I had conneced my digital pin of arduino to the uln2803a to drive LED. I want to configure my uln2803a such that i can connect +ve side of the led to the output pin of uln2803a IC.
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2 votes
2 answers
166 views

Unusual behavior when controlling a Button Matrix

I have a 4x4 matrix for 16 buttons. Each row/column is directly connected to the pins of an unknown microcontroller. When I connect the pins directly to each other, the microcontroller behaves ...
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