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Comp.Arch.Embedded is a worldwide Usenet news group that is used to discuss various aspects of Embedded Systems development.
We found 645 threads matching "led"
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Re: Finding power - gnd shorts
Eric Smith - 20:14 23-07-08
rickman wrote:
> As a matter of fact, the last day job I had the company had just
> bought a $50,000 TDR. I am sure fixing a $150 board is exactly the
> job they had planned for it. Even with that, I'm not sure it could
> show me the short.
It wouldn't easily identify the physical locat...
Ethernet Terminal I/O board
trex - 08:38 21-07-08
Hi everybody,
I am trying to make a ethernet terminal I/O board. Basically making an x86
based 1U solution. I am trying to route the onboard ethernet connection via
a patch cable (Cat6). this works but I also want the link/status leds.
I did a simple PCB with two modular 8P8C Jacks with LEDs a...Re: Micro-SD card initialisation-problem - Resolved
Mark Borgerson - 13:17 19-07-08
In article ,
address@not.available says...
> R.Wieser schreef in berichtnieuws
> 487f9cf0$0$14357$e4fe514c@news.xs4all.nl...
> > Hello all,
> >
> > I've connected a Micro-SD card to my printerport (using very simple 5v
> to
> > 3v voltage-step-down by three diodes and a re...Timer ticks occurring much more faster
ratemonotonic - 12:04 09-07-08
Hi All ,
I am implementing RTC code on an AVR Atmega2560 I have a 32Khz clock
crystal to TSOSC1 which is used by timer2 in async mode. I have
configured the clock divide to 8 so the clock to the timer is 32768/8
= 4096. It is a 8bit so a interrupt should be generated every 16hz
(4096/256).
...Re: Orthogonal matrix PS/2 kbd controller, low-power?
msg - 13:17 07-07-08
msg wrote:
> larwe wrote:
> > But why don't you buy a $10
> > rubber "rollup" keyboard off eBay and attach a couple of velcro strips
> > to it?
>
>
> Those rubber rollups were the first option I investigated...
Also, they certainly aren't marketed as low-power, all...RS422 interface
svyamuna - 13:15 07-07-08
I am trying to interface two systems through RS422 link. There are only
four lines connected between them (tx+/- & Rx+/-) and no ground.
Independently both systems work fine but when interconnected and i try to
communicate with each other there are some problems. initially master
units Tx lines hav...Re: tiny inductor with every bypass cap?
Terry Given - 19:04 23-06-08
Joerg wrote:
> Terry Given wrote:
>
> > Joerg wrote:
> >
> > > Terry Given wrote:
> > >
> > > > Joerg wrote:
> > > >
> > > > > John Larkin wrote:
> > > > >
> > > > > > On Sun, 22 Jun 2008 13:03:09 +0000, Guy Macon
> > > > > > wrote:
> > > > > >
> > > > > > >
> > > > ...at91sam7: garbage on DBGU output
Roman Mashak - 22:20 16-06-08
Hello,
MCU - at91sam7s64
toolchain - Yagarto (based on gcc-4.2.1)
I have two distinct applications residing in the internal flash. The first
one located at 0x100000, prints string and transfers control to the second
application located at 0x104000, which lights the LED and prints a string...Re: Please suggest USB to RS232 adapter that works 100% [ FTDI rocks... and tunnels a serial port through USB ]
=?ISO-8859-1?Q?Glenn_M=F8ller-Holst?= - 02:49 13-06-08
CBFalconer wrote:
> Tomás Ó hÉilidhe wrote:
> ... snip ...
> > Can anyone suggest a USB to RS232 adapter that does its job
> > perfectly 100% of the time under Microsoft Windows, i.e. it
> > trully behaves exactly just like any other serial port?
>
> Impossible. USB is not a serial p...Re: Connecting buttons with MSP430F2013 for Input Output with software
Jonathan Kirwan - 15:18 10-06-08
On Mon, 9 Jun 2008 10:59:54 -0700 (PDT), anmol
wrote:
> I want to connect 5 buttons with the MSP430F2013 MCU . I want to use
> the buttons for input with a software . Please help and tell me how
> to go about the task . If you have any tutorial , curcuit diagrams ,
> videos please give t...AT921SAM7: jump to address in flash
Roman Mashak - 19:25 09-06-08
Hello,
MCU: at91sam7s256
toolchain: Yagarto (based on gcc-4.2.1)
First image XXX bytes length is burnt on the flash at the very beginning, by
address 0x100000; second image resides on the flash at the (0x100000 + XXX).
First image prints a short debug message out on DBGU port and then sho...Microcontroller-related engineering jobs
Jason Hsu - 20:49 02-06-08
I am seeking an electrical engineering position that has a heavy
emphasis on microcontroller-based circuits. I believe these positions
are usually called "firmware engineer" or "embedded engineer".
I don't have formal experience in firmware/embedded engineering, but I
do have informal experien...Re: ARM9 STR912 IRQ woes (GCC/Eclipse/OpenOCD)
frikkiethirion - 11:39 02-06-08
Hi Richard
> Sorry if this is a statement of the obvious, but have you checked that
the
> I bit in the status register is set such that interrupt are globally
> enabled?
I've double checked my startup assembly again and found in the section
where the stacks are defined that no mention is m...Driving tri-state LED matrix
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 08:18 30-05-08
The objective is as follows:
uC pin set as output high: The Green LED lights up
uC pin set as output low: The Red LED lights up
uC pin set as input: Both LED's are off
There will never be a time when both LED's are lit.
Here's what I'm currently thinking of for th...Re: MC68020 Embedded System HW Reset Problem - Need Help
Gene S. Berkowitz - 23:42 28-05-08
In article ,
jflan@tampaREMOVEbay.rr.com says...
>
> Hi -
> I am hoping that someone could give some pointers as to how
> and attack a reset (double bus fault) problem with an embedded
> 68020 board that was originally designed by HP in a piece of
> test equipment that was mfg back ...Voltage from high impedence? (Newbie)
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 14:42 27-05-08
I understand from studying electrical science that the "ideal volt
meter" would have infinite resistance and that it would draw no
current whatsoever.
However I know in reality that our volt meters have a little bit of
conductance and thus a tiny bit of current flows thru them. It seems
the h...Re: Most suitable driver chip
Robert Adsett - 12:05 26-05-08
On May 26, 10:49 am, Tom=E1s =D3 h=C9ilidhe wrote:
> On May 26, 12:11 am, Spehro Pefhany
>
> wrote:
> > > I'm going to try get my hands on LED's that are bright in natural
> > > daylight. Do you think I'd get much performance out of any such LED's
> > > for 25 mA.
>
> > Ave...Most suitable driver chip
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 18:12 22-05-08
I have a matrix of LED's, six rows and seven columns:
X X X X X X X
X X X X X X X
X X X X X X X
X X X X X X X
X X X X X X X
X X X X X X X
Across th...Re: Microscope Recommendations
Rich Webb - 16:29 22-05-08
On Thu, 22 May 2008 15:41:55 -0400, Blip wrote:
> Now that almost everything I do is SMD stuff, I'm thinking about
> trying to pick up a stereo microscope from ebay. They have pretty good
> prices on 40x scopes. What value of magnification is best for checking
> solder on boards? What are t...Best way to get 2.5 volts from somewhere? (Vcc = 5 volts)
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 14:27 13-05-08
I've got a bi-colour LED. It has two pins. Internally it consist of
two LED's in parallel except they face in different directions.
I'm looking into ways of using one micrcontroller pin to control the
LED as follows:
Pin High = Light up Red
Pin Low = Light up Green
Pin as Input...My idea of fully-portable C code
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 18:10 12-05-08
I've been talking about portable C programming lately, and I've
claimed that I write fully-portable code. Many people here contested
this claim, some more rudely than others, so instead of trash-talking
back and forth I'm going to actually give an example of the way I
code.
In my most recent ...Pull up resistor on the gate of a PMOS
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 11:00 11-05-08
I have a tri-colour LED which consists internally of two LED's that
have a common cathode. The device has 3 pins (two anodes and one
cathode).
Using one microcontroller pin, I want to light the LED either red,
green or off. The microcontroller's pin states are intended to be as
follows:
Hi...Re: code optimiation
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 10:31 11-05-08
On May 11, 2:26=A0pm, Hans-Bernhard Br=F6ker
wrote:
> Tom=E1s =D3 h=C9ilidhe wrote:
> > * Integer types may contain padding bits, and so sizeof(type) *
> > CHAR_BIT won't necessarily give you the amount of bits in a integer
> > type.
>
> On the contrary, that's exactly what it giv...[EE] GPS logger with voice recording - Wear balancing for SD/MMC card needed?
wzab - 17:19 10-05-08
Hi All,
I'm just working on the open source GPS logger with voice recording (to
facilitate recording tracks for the http://www.openstreetmap.org project).
The current architecture includes:
GPS module - http://www.f-tech.com.tw/datasheet/GPS/FGPMMOPA2.pdf -
first tests show, that it perform...Re: PMOS in parallel with NMOS
Spehro Pefhany - 14:40 08-05-08
On Thu, 08 May 2008 19:21:02 +0100, John Devereux
wrote:
> Tomás Ó hÉilidhe writes:
>
> > On May 8, 6:35 pm, rickman wrote:
> >
> > > But what did you learn? I can assure you that if you try to implement
> > > a design like this in a job, your peers will not let you go to
> ...PMOS in parallel with NMOS
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 23:52 06-05-08
Let's say I have a microcontroller pin that will have one of three
states: 5 V, 0 V or high impedence.
Let's say I have a PMOS and an NMOS, and I connect their gates
together. I connect the microcontoller pin to the gates.
Now, when my pin is high, the NMOS will turn on. When the pin is lo...Loss of synchronisation: Are the chips reliable?
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 14:44 06-05-08
A lot of you are familiar with the method of using a shift register to
multiplex a matrix of LED's.
My college project this year was to make a Connect4 game consisting of
a 7x6 matrix of LED's.
I had two choices for implementing the display:
1) Use two pins from the microcontroller
...Re: Just assume that it's not in a defined state?
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 14:53 04-05-08
> Just out of curiosity - what are the other pins on the PIC being used
> for?
I've 12 pins available altogether:
* 7 are going to LED's.
* 1 is clocking a counter.
* 3 are taking input from buttons.
* 1 is turning a piezo speaker on and off.
Here's my current schematic:
http://f...Re: Simple Clockable Decoder Chip
Rocky - 14:37 03-05-08
On May 3, 7:44=A0pm, Tom=E1s =D3 h=C9ilidhe wrote:
> Let's say we have an 8-Bit shift register. We reset it so that its
> outputs are as follows:
>
>
> Then again I could always just use two of these chips, but I just
> thought I'd check to see whether there was a more suitable chip...Re: Inputs left floating at the very start
linnix - 11:37 03-05-08
On May 3, 5:37=A0am, Tom=E1s =D3 h=C9ilidhe wrote:
> In college, I was always told not to leave input pins floating on a
> device such as a 74HCT chip. I was told that the device might behave
> erratically if any of its inputs are floating.
>
> I have the PIC16F684. One of its inputs go...A few novice questions
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 15:27 02-05-08
I've a decent enough knowledge of electronics but I'm not very big up
on what's being used today in embedded systems.
For instance, in my college course, we use chips in the "74HCT" family
and we use transistors such as BC337 and TIP121 as switches.
I've been asking around and it seems tha...Re: Task priority for UI task handling menus and other controls
Vladimir Vassilevsky - 19:32 01-05-08
Steve Watt wrote:
> [0] OK, a continuous 200 ms lag of response in my joystick would make
> landing on a carrier somewhat harder. On the other hand, if it was
> always there, it could be trained around and compensated for.
The occasional delay in the reaction of the user interface ...Re: Debugging: Am I a dreamer. . . ?
Ed Prochak - 09:02 30-04-08
On Apr 29, 10:21 pm, Tim Wescott wrote:
> On Tue, 29 Apr 2008 16:45:34 -0700, Tom=E1s =D3 h=C9ilidhe wrote:
> > I've been programming in C for the best part of a decade now but it's
> > only within the last year that I've really started doing embedded
> > systems programming.
>
> >...Driving a led without a series resistor (PWM technique)
02:52 30-04-08
Hi,
I'm designing a board where the microcontroller is supposed to drive
10 red leds and 4 optocouplers.
I would like to drive the leds and the opto's without a series
resistor using the PWM technique. I made some experiments and all
seems to work fine in the lab.
1. The supply voltage i...Re: Luminary Cortex ARM toolchain thoughts?
FreeRTOS.org - 17:34 26-04-08
"larwe" wrote in message
news:5f9543eb-c46c-4d3b-b4aa-dc69b743a8c5@b9g2000prh.googlegroups.com...
On Apr 26, 8:14 am, "FreeRTOS.org" wrote:
> > Just for completenesshttp://www.rowley.co.uk
> >
> > (Used that lots too, very nice, clean, easy tool. Also uses the
> > CodeSourcery com...Re: mixing C and assembly
Bill Leary - 19:09 23-04-08
"Walter Banks" wrote in message
news:480FAC36.E382E22B@bytecraft.com...
> > Why would you bother optimising a traditional call to main into a jump?
>
> When C runs on embedded systems processors that are not hosted main should
> never return.
Usually, no. But it's a good idea to ma...Re: Getting fit with embedded systems
Alex Colvin - 15:19 23-04-08
> -- nothing says "I really build stuff" quicker than pulling something
> that you built out of your briefcase.
Just don't do it in Boston's Logan airport. They're suspicious of LEDs and
things with wires ;).
--
mac the naïf
...Re: Monochrome LCDs
larwe - 07:26 23-04-08
On Apr 23, 4:55=A0am, "ydoubl...@gmail.com" wrote:
> Just about to begin some works on Monochrome LCDs. I had some
> experience dealing with those characters LCD driven by HD controllers.
What kind of monochrome LCDs? There are some simple LCDs with the
controller integrated on the glas...MSP430-ez430 Basics - reading in pushbutton values
Hamza - 13:33 21-04-08
Hi all,
I just received my ez430 and the extra modules (with MSP430F2012) and
I am just trying to get my head round some basic stuff, like reading
in a port value to detect pushbuttons etc. I must say I am not very
experienced so please be gentle :)
I've connected two pushbuttons, one to P1...Some sort of anti-glare screen?
=?ISO-8859-1?Q?Tom=E1s_=D3_h=C9ilidhe?= - 07:11 20-04-08
My project board looks great in a dimly lit room, the LED's are nice
and bright. In a well lit-up room though, it looks crap.
I'll be putting my board in a transparent perspex case. I wonder is
there any kind of layer or coating I can put on the perspex so that
the LED's will look bright i...