255 Threads found on edaboard.com: Led Example
I agree with d123.
* Fuctionally you may use the 4067.
* There are dedicated relay driver ICs. They may be controlled with SPI or I2C
* you may use some logic IC like HC138 combined with a led driver like ULNxxxx
There are many, many example circuits here in this forum and even more in the internet.
Hobby Circuits and Small Projects Problems :: 03-23-2017 06:59 :: KlausST :: Replies: 4 :: Views: 565
I want power my led using I-Phone lightening connector.
Have anyone tried to do that or Did you have any suggestion for me?
For example:- Powering a USB fan. Instead of USB ,I want to use I-Phone to power on my led.
Power Electronics :: 12-17-2016 14:17 :: Manivannan M :: Replies: 0 :: Views: 382
A vague description...leads to vague answers..
I assume with "current limiter" you mean someting like a inrush current limiter for transformers.
If this is the case, then it is completely unsuitable for leds.
Please give more details or example circuits, links to datasheets, web pages, discussions, or device names.
Power Electronics :: 07-02-2016 09:11 :: KlausST :: Replies: 2 :: Views: 395
As soon you will show your code and schematics, as far you will get any usefull help.
i've tried learning C from example9 :two digit led counter
but its not working even after correction of MikroE team
here is the schematic
Microcontrollers :: 04-21-2016 07:48 :: janosandi :: Replies: 15 :: Views: 1171
After using mTouch framework, I am trying my hand on dedicated CPS channels (CPS0-CPS16). I have written the code for same which looks running except some pitfalls as follows.
When I press input X (for example), led for (X+1) glows. I see, everytime i call ISR kaflg value is written at kflag. please help me to
Microcontrollers :: 04-11-2016 16:04 :: pravin b :: Replies: 3 :: Views: 805
I have an led board where i want to add a circuit to control the brightness,
input parameter of the led board DC voltage ( 12V, 350mA),
i want to add a circuit in such a way that when the voltage turns from 12V to 0V and again 12V ( low pulse of few ms) the current decrease ( for example from 350mA to 200mA),
and when again i do (...)
Elementary Electronic Questions :: 04-08-2016 08:12 :: yassin.kraouch :: Replies: 6 :: Views: 805
My name is Ashley, I live in the UK, I work with alarm systems but have not worked at a component level for quite sometime.
I have a variety of bit at my disposal and have retro fitted my gun cabinet with a 12vdc led strip light.
The Magnetic contacts I use in work are what we call normally closed for example when a door is in its closed pos
Hobby Circuits and Small Projects Problems :: 03-08-2016 09:20 :: daiashthomas :: Replies: 0 :: Views: 2
I need to rotate for an example x=0XFF for 3 to right.
I cant do that only with >> because that is shifting.
When you want rotate you need to "memory" all bit not to lose such as in case for shifting (i think).
So that is not the same.
May I use this
display= (x & 0xFF)>>3 ; // display is diodes which simulating bits...
Microcontrollers :: 02-09-2016 15:06 :: 8051HELP :: Replies: 0 :: Views: 16
I have never played with the Sitara boards, but an SPI screen is really easy to use.
If you find a way to use GPIO (try to blink a led for example) and a SPI, then you just
wire the SPI to the LCD, the GPIOs to the proper places (usually chip select, Data/Command,
Reset) and you're on the right way.
Usually you can find the initialization p
Microcontrollers :: 12-25-2015 12:00 :: doraemon :: Replies: 1 :: Views: 988
Can you separate the loops for scanning the matrix display and for moving the characters.
For example, you can create a loop that writes to the entire matrix every mSec (say) but only shift the characters every 100 times ( of whatever) through that loop.
I assume that the brightness form the matrix is a direct function of how long you keep the led
Microcontrollers :: 11-23-2015 01:47 :: Aussie Susan :: Replies: 2 :: Views: 766
There must be 50,000 led driver designs in production by now.
If you are referring to a long string of leds with a buck CC regulator from a HV source, then a HV process is used.
But not for a LV solution
For example this part has a range of 2.5 to 6V and can supply leds up to 3A. for only $0.95 with 470nH choke total BOM (...)
Power Electronics :: 11-11-2015 21:26 :: SunnySkyguy :: Replies: 3 :: Views: 682
If the displays are only 7 segment you only need 7, PORTD pins for the segments and another PORT's 4 pins for digit select.
This will leave PORTD.0 free for the serial RXD.
ULN drivers were used as they were very large led's
Microcontrollers :: 09-26-2015 11:40 :: esp1 :: Replies: 11 :: Views: 960
Besides the low current capacity mentioned above, you need to be aware that using some led with color other than red, this effect is even more noticeable because the voltage drop will be greater in other colors. What you can do is to use a transistorized external circuit to amplify this current, like the ULN2003 IC for example.
Microcontrollers :: 08-18-2015 11:16 :: andre_teprom :: Replies: 33 :: Views: 1912
I'm using the LT3797 led driver in a SEPIC configuration. It uses a high-side currents sense resistor to set the output current. I'm following this circuit example for my application.120053
I would like to be able to "scale" the sense resistor on-demand (from a microc
Analog Circuit Design :: 08-12-2015 15:33 :: jstamour802 :: Replies: 4 :: Views: 838
I'm new to this, but I need help writing a code (MPLAB in C) for a frequency counter with a 4x 7 segment display using a PIC18f252, and a 74HC4511 driving the display.
it needs to work in the range 15hz to 200hz.
Thanks so much if any one can help ;)
Microcontrollers :: 07-14-2015 12:02 :: Kerryannewood :: Replies: 3 :: Views: 583
For a state machine, you have to list up the possible states (and combinations of states), and
list up the inputs / events that cause changes from a state to another. Here is an example (not
in C, in pseudo code with a C syntax).
Let's say you want to toggle a led with a button press. You have 2 states, led_ON and (...)
Microcontrollers :: 06-20-2015 01:34 :: doraemon :: Replies: 3 :: Views: 536
THis is a good example of a cheap design that costs about 50 cents to make in CHina. What did you pay?
REMOVE all 100 Ohm resistors for 27 V use. I assume you didn't get instructions.
THe middle Resistor is beyond rated power with taillight on only 380mW so will rather hot to touch and should use two 1K resistors or so in parallel for cooler oper
Hobby Circuits and Small Projects Problems :: 06-17-2015 09:05 :: SunnySkyguy :: Replies: 12 :: Views: 989
Texas Instruments datasheets for CD4xxx ICs show detailed graphs of minimum and typical output current sink and source at 3 supply voltages. The graphs allow you to select a load voltage drop (I use an led forward voltage). For example with a 10V supply the typical shorted output source current is 20mA or 18mA into a white 3V (...)
Analog Circuit Design :: 05-22-2015 01:52 :: Audioguru :: Replies: 2 :: Views: 452
I have recently discovered that a 4kV ESD event was causing my board to fail due to a discharge on the RJ45 shield, which then traveled to the led and into the IC causing it to fail.
What is a good way to protect that IC for FCC cert, and is there a good doc/example out there? I did put protection on the datalines, but didn't think of (...)
Professional Hardware and Electronics Design :: 05-07-2015 21:00 :: jelydonut :: Replies: 2 :: Views: 1259
117106117106Hello I need advice for my solar tracker system. I'm trying to create light sensor using LM358 OA and led sensor diode. I use controller measurement light signal. I use controller Atmega32 which I connected with OA output (with ADC port). I protect it from high voltage signal with SD. So I
Elementary Electronic Questions :: 05-03-2015 09:40 :: Ignas Pranckevi :: Replies: 7 :: Views: 801