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-1
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0answers
5 views

dividing node matrix to tree-branches and links [on hold]

A is the node matrix Aj = 0 if we have A = [A_l|A_t] show that A_t is always invertible ? (A_t is a part of matrix A which relates to tree branches)
13
votes
1answer
363 views

Studying the PCB of a 70s calculator. What were they thinking?

I've been studying the PCB from an ELSI 8002 calculator from 1974. I'm thinking of repurposing the case for a project, though now that I've fixed it (by re soldering the battery connectors) I don't ...
1
vote
2answers
91 views

Creating a DC resistor network matrix

I have the following resistor network and I need to make a 7x7 matrix which would be the solution . I know the resistor values, but not the v1, v2, v3 or any of the current. I'm supposed to combine ...
0
votes
1answer
20 views

Certain property of a bus admittance matrix

I have got a simple network for my assignment: I know bus admittance matrix have certain properties that let us form the matrix without writing so many lines of ...
-3
votes
1answer
32 views

Simple Matlab Problem [closed]

I just started working with Matlab last week, so I'm very new. After searching for a while, I realized that I don't know how to fix a Matlab script that I'm working with. The problem is given below. ...
0
votes
0answers
30 views

Admittance matrix of an amplifier

I'm trying to determine the admittance matrix of the following amplifier : I found the following results : $${i_1 \over V_1} \stackrel{V_2=0}= {1 \over Z_e}$$ $${i_2 \over V_2} \stackrel{V_1=0}= ...
1
vote
2answers
55 views

state-space model of non-linear system?

This is the equation for which I have to make a state-space model. $$m\ddot y(t)+b\dot y(t)+k_1y(t)+k_2y(t)^3=u(t)$$ For my A matrix I have $$\begin{bmatrix} 0 & 1 \\ ? & \frac{-b}{m}\\ ...
0
votes
1answer
79 views

Interfacing thousands of RGB LEDs in a matrix

So I have 3072 RGB LEDs I need to connect in a matrix. I have decided to split the project into smaller matrices and all LEDs are common Anode. Datasheet for LEDs is here: ...
15
votes
5answers
1k views

Making an electronic chess board

I want to make a wooden chess board that you can play on with regular pieces (i.e., not modified pieces that make use of RFID codes, magnets, …), but that is connected to a software that takes notice ...
1
vote
0answers
48 views

col not declared issue{Verilog}

I am having a problem here can't make this code compile. It is a 4x4 keypad scanner with a 20ms debouncer. It gives error "Error: 'col' has not been declared" Any suggestion? ...
0
votes
1answer
70 views

4x4 keyboard matrix not generating unique keycodes

I have a 4x4 keybord matrix fsm scanner but it generates only high keycode setting all last 4 bits to 1 and second and fourth digits to high. Is there anything wrong in my code here? ...
1
vote
1answer
119 views

How to write a counter in verilog for debouncing an input?

I am trying to write a module counter to debounce a input coming from mechanical buttons. The module should be controlled by the 4x4 matrix button module when to start or stop debonce. This is my ...
0
votes
2answers
125 views

Why does my Verilog code for 4x4 button matrix not scanning?

I have a problem with a module in Verilog where I need to scan a 4x4 button matrix. I don't get to scan each row 1 by one but the thing stick with the first row. Can you help me debug it? To me it ...
1
vote
2answers
91 views

Mesh Current method for solving a variable resistor?

I have a circuit with a variable resistor R which I need to find the value of. I am told that the power dissipated in the resistor is 250W. The circuit: I used the mesh current method naming the ...
0
votes
2answers
117 views

Illuminated SPST Switch

I am building a HID device (for flight/space simulators) with an Arduino Micro that will have a 7 column and 4 row matrix plus 4 axes. I have the matrix working fine with normal buttons and switches ...
2
votes
1answer
54 views

Physical significance of singular matrix in two port network

In class we've been introduced to two port networks, and I was wondering: Is there a physical significance to a singular matrix in a two port network, or is it simply where the mathematical model ...
1
vote
1answer
2k views

Keypad Scanner Verilog code problem with state machine and column input

I am developing a Keypad both in hardware and Verilog using a DE2 Cyclone II board. I made a keypad using buttons (switches) that follows this schematic: The scanner works by setting the Column ...
1
vote
1answer
47 views

how to calculate Hermitian Toeplitz system of equations on fpga in vhdl

I'm trying to write vhdl code to solve the Hermitian Toeplitz system of equations (solving for the A's). ...
0
votes
3answers
628 views

How to calculate power requirements of LED matrix, per row or per LED?

I have built an LED matrix (9x9) and want to run it with Arduino. I am using technique of scanning, lighting up 1 LED at 1 time. The more I am reading about power requirements of a matrix the more I ...
0
votes
2answers
127 views

switch matrix with ring counter

Hello I am creating a little device, which has a total number of 30 tactile switches arranged in a matrix with 3 rows and 10 columns. My problem is, that I have only left 5 IO pins on my AVR ...
0
votes
1answer
61 views

Matrix switch module for electronics testing - what uses?

I'm doing a presentation about NI PXI and such test equipment for school. And I am explaining what the multiplexer and matrix modules can be used for. The multiplexer is simple: Connect, for ...
0
votes
1answer
525 views

Custom built 16x32 (40) LED Matrix controlled by Arduino

I am planning to build a clock / thermometer / info display. I have ordered 10 pieces of 8x8 LED matrixes from ebay (http://www.ebay.co.uk/itm/331064583297). As this is not a pre-built one I have got ...
1
vote
2answers
648 views

Raspberry Pi + Microcontroller for commuting audio input and output (audio matrix switch) [closed]

I am new in electronics and I'm working on a personal project with Raspberry Pi that I need help. I want to make a board that allows to commute 4 audio inputs (TV, MP3, DVD, FM web) in 4 audio ...
2
votes
3answers
1k views

Shift Register turning on Transistor for LED Cluster

I have a question concerning using 74HC595 with two transistors to power a LED matrix. My goal is to make an 48 x 8 LED matrix using a cluster of 5 LEDS per unit (as opposed to only using one led as ...
1
vote
4answers
3k views

LED matrix dimming: How to control the current in a 12V LED lamp for video lighting?

I'm trying to dim a 12V LED lamp (LEDs specification here however schematics have the real values...) I've build for a video lighting application. My initial thought was to use a potentiometer but it ...
2
votes
1answer
82 views

Reading to PIC32MX's memory in C and XORing big sets of data

I have a project in which I have 102 8-bit PISO shift-registers in daisy chain configuration and they are outputting to a common SDI line connected to a PIC32MX controller. There is a total of 816 ...
2
votes
1answer
3k views

Why there is a factor 2/3 added to Clarke Transform matrix?

Apparently, the matrix to transform the 3 vectors \$ U_a , U_b, U_c \$ into \$ U_\alpha, U_\beta \$ is: $$ \begin{bmatrix} U_{\alpha} \\ U_{\beta} \\ U_{0} \\ \end{bmatrix} = \begin{bmatrix} 1 ...
2
votes
2answers
1k views

Brightness issues driving 10*11 SMD 5050 LEDs matrix

I'm working on driving a 10*11 LEDs matrix by a µC since a while, and I decided to come to you because I'm a bit surprised/annoyed by my results. So, I first started with simple 5mm white LEDs ...
4
votes
2answers
147 views

Why aren't SRAM modules laid out in a matrix?

I'm currently reading about RAM modules. Bigger DRAM module are laid out in a matrix. When retrieving data you first retrieve the row and then the column. One of the benefits of the matrix lay-out is ...
2
votes
1answer
309 views

Need help setting up 7X6 Piranha LED Matrix with Arduino

I need help correctly getting my parts list for a 7X6 matrix that will be part of a electronic outdoor scoreboard. Here is my parts list so far but I am stump whether the arduino is powerful enough ...
0
votes
2answers
451 views

How to drive 32-by-32 (or more) LED matrix? [duplicate]

I have a matrix of 32-by-32 LEDs that I need to control using a driver. The largest driver that I found was a 16-by-16 driver by Linear Technology, and there is no driver that goes higher than ...
10
votes
2answers
1k views

LED Multiplex Anode-Row Driver

I'm helping build this art installation that amounts to a large 16 x 16 pixel display. I settled on using 16 TI TLC5926 constant current driver chips chained together to give me direct drive to each ...
3
votes
1answer
219 views

Connecting a N.O. grounded switch to a scanning switch matrix

I am working on a project that includes a scanning switch matrix. It also includes a joystick with an integrated push button. I am out of IO pins on the micro, but there are gaps in my switch matrix, ...
3
votes
3answers
798 views

How does the ZX80 keyboard avoid ghosting and masking?

I believe that a keyboard matrix needs a diode on each key to avoid ghosting and masking. http://pcbheaven.com/wikipages/How_Key_Matrices_Works/ The ZX80 (and probably ZX81) has only a diode for ...
0
votes
1answer
904 views

How to Create an RGB LED Display for Raspberry Pi?

I'm relatively new to hardware. I have some basic concepts down and I've only done some basic circuitry, but I really want to jump into the deep end - it's how I learn best. I'm not sure how simple ...
1
vote
1answer
1k views

How Can I Program an LED Matrix

I got this really cool idea the other day. Sitting in my Computer-Sci Lab at school I saw the binary clock on the wall. As a "watch guy", I immediately wanted a watch like it. I've always had a DIY ...
5
votes
2answers
2k views

Using a TLC5940 to control LEDs with different forward voltages

I am trying to build an LED matrix (64x32) of RGB LEDs using a TLC5940 current sink LED driver. The forward voltages of the LED components for each RGB LED are: R: 1.8V G: 2.8V B: 2.8V The driver ...
1
vote
1answer
1k views

How does an LED matrix work?

I've wired up a 3x3 matrix as in the attached image. My understanding is that if I apply 3.3 volts to row C and connect column 1 to ground, the electricity should flow through the bottom-left LED (as ...
1
vote
4answers
3k views

20x20 RGB LED Matrix controller project

I've been wanting to start a project with the following requirements: Be able to display a static image, composed of 19x19 RGB pixels (though I expect to have to use a 20x20 matrix). Be small (in ...
0
votes
1answer
501 views

How to hook up circuit to drive 5x7 1 Watt White LED

I am not a electronics guy but want to design a display using 5x7 Ultra Bright 1.2 W, 350 mA OSRAM DRAGON-X Plus LED. I want to have a simple circuit so as to be able to control (Switch ON/OFF) ...
0
votes
1answer
51 views

Routing Current to Many Individual Channels [duplicate]

Possible Duplicate: How to implement an isolated connection matrix I need to put current on up to 30 lines; one at a time. What kind of electronics solutions are there to this kind of ...
5
votes
6answers
14k views

How do I control several hundred individual leds with Arduino(s)?

I am working on an electronics project which involves hundreds of LEDs. (Talking upwards of six to seven hundred LEDs...a lot, I know.) Is there any way to control this many LEDs with one or a couple ...
5
votes
1answer
990 views

Led Matrix using PIC

For a project I am working on, I want to build a 9x9 monocolor LED matrix also with 9 push buttons to control the LEDs using the PIC. So far I have gathered that I think I will be needing shift ...
1
vote
1answer
1k views

How to control and power 25 x 25 nichrome wire matrix

I would like to control and power a 40x40mm size array of 25 x 25 small heating elements which should function just like a visual display of LEDs, but switching heating elements on/off instead. I am ...
4
votes
1answer
4k views

Driving a common cathode 8x8 RGB LED Matrix with PWM

I've got this nice RGB LED Matrix. My goal is to use several of them to create a 16x16 color display. Unfortunately, the display is common cathode. From experiments driving a single LED with 8-bit ...
1
vote
1answer
417 views

How can I matrix switch multiple lines, including power?

I have devices with several similar boards, all of which are basic computers (with CPU, RAM and ROMs etc.). They all interface to the I/O unit via a standard connector, although the connectors aren't ...
2
votes
1answer
6k views

Rotating a gyroscope's output values into an earth-relative reference frame

For whatever reason, I seem to have gotten myself twisted into quite a confusion on how to process data from my 3 axis gyro and 3 axis accelerometer to get gyro rotation values related to the earth's ...
0
votes
2answers
1k views

Arduino Row Column Scanning not working

I tried to follow this tutorial but the whole matrix is always lit and only one row and one column does not light. I am pretty sure I did the wiring correct; I only have slightly edited the code ...
1
vote
2answers
478 views

Huge led matrix - using mm5451

Hi I'm using the MM5451 led driver chip to source current for my led matrix. Am told that the chip has open drain outputs. To source current from the chip do I just connect the anode of my led to the ...
2
votes
2answers
2k views

Feasibility of controlling a dimmable LED matrix

I have a beginners question: I'd like to create a custom LED matrix (at least 7x7; one-color only), where each row of LEDs can be dimmed separately or ideally even each LED. The whole thing should be ...