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1
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2answers
91 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
83 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 ...
0
votes
0answers
31 views

Reading an irregularly shaped matrix and doing action when a key is pressed in a modular way

Before I get into the details, I'd like to apologize if this is the wrong SE site for this. I could see it going on here, Stackoverflow, Arduino, or maybe even code review. I am using a Teensy 2 as a ...
1
vote
4answers
467 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
64 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
242 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 ...
0
votes
0answers
200 views

How to drive a 16x16 common cathode dual colour multiplexed LED matrix?

I tried using specialized LED drivers at first but found they're pretty much all made for common anodes since they switch on the low side. So I came up with the following transistor-based driver ...
2
votes
2answers
504 views

Brightness issues driving 10*11 SMD 5050 LEDs matrix

I'm working on driving a 10*11 LEDs matrix by a ┬ÁC 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
116 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
209 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
271 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 ...
9
votes
2answers
867 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
167 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
380 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
0answers
613 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
647 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
839 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
735 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
2k 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
328 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
49 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 ...
3
votes
5answers
5k 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
701 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
709 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 ...
3
votes
1answer
2k 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
352 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
3k 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
1answer
616 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
421 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
1k 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 ...
1
vote
1answer
489 views

Controlling a 49 two-color LED matrix

I have a total newbie question; for now I'd only like to know if the following is doable with minimum effort: I'd like to create a custom 7x7 two-color LED matrix, where each row of LEDs can be dimmed ...
1
vote
3answers
626 views

Displaying text on a LilyPad?

What are the best options to show a line of text on a LilyPad Arduino, probably using a matrix of LEDs? Are there any thin and inexpensive displays? The main problem is that the only things I can ...
0
votes
1answer
1k views

Why my 16x16 LED matrix show only lines?

i bought from web one of this matrix: http://tinyurl.com/3zjhuk7 I followed all instructions and i connected it to my arduino uno without sensor shield (it's necessary?). I've used IN pins of the ...
3
votes
2answers
921 views

Driving a LED Matrix with a N-channel MOSFET (2N3819) using an AVR

I am trying to wire up a LED matrix using a FET transistor as a switch. The AVR will be connected to the gate. To turn the LEDs on I have drive the pin connected to the transistor gate low, right?
1
vote
3answers
2k views

how to drive 5x5 IR LEDs with 100 mA, using Arduino

I am trying to do my first Arduino project, and I would like to drive a 5x5 matrix of IR leds. I would only like to have one switched on at a time. I understand that in an array I can do it with 5 ...
5
votes
4answers
2k views

arduino 3x3 LED matrix

i am trying to get a 3x3 matrix with multiplexing up and running. here is my setup: i have connected each rows cathodes and each columns anodes and connected that one to pins 0,1,2 resp. 8,9,10 ...
0
votes
2answers
489 views

Microchip PIC18 matrix routines

I'm using a Microchip PIC18 and I need to use matrices in my code. I know DSPIC do have matrix libraries, that simplifies the implementation. Does anybody know whether any is available also for the 18 ...
0
votes
4answers
356 views

Form factor for a large LED array on a small board

I am designing a fairly simple board with an 5x8 LED matrix. I plan to drive it with an LED driver I haven't chosen yet, probably on a separate board connected by a ribbon cable. My question is: ...
7
votes
4answers
5k views

How to hook up a 5x7 LED matrix to Arduino?

What is the best way I can hook this 5x7 LED matrix to an Arduino board?