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41 Threads found on Led Multiplexing
By strobing I suppose you mean... (a) flashing each led for a brief instant, (b) multiplexing the led's in rotation? An easy way to do item B is to use a 4017 IC (1-through-10 sequencer). It rotates a clock signal through 10 output pins. You probably want to light each led for a brief instant. (Item A above.) Your (...)
I doubt the led/transistor current is only 20mA because they are multiplexed. multiplexing causes PWM dimming so the peak current must be pretty high to make enough average current. As you can see from the specification for saturation, beta is not used when a transistor is used as a switch. Beta is used when a transistor is a linear amplifier with
Hello All, I am working on displaying day, date & time information on 7 segment led using 74HC595 shift registers and COMMON ANODE configuration. Please see my attached diagram. I am explaining the acrchitecture as follows: 1) The top row displays time in HH:MM:SS format. 2) The middle row displays date in DD:MM:YY format. 3) The lowest row
Hello friends i want to create 3 seven segment led drive using At89c51 micro controller ? how can i start ? and also i want to create using switch or variable POT to increment or decrement the digit . and is that possible to save last digit at device power off and after some time power on last value stored using external eepr
Hi, on first sight it seems ok. But the display seems to be an 4 x 7- segment led display. It is in multiplexing technique. Mind that the current on the digit wires (1, 2 , 3, 4) must handle max. 8 x led current. Now it depends on the led current if the AVR can source current. Also mind that with (...)
hi, I'm using PIC18LF2520. Internal oscillator: 1Mhz, CCS C Compiler I'm using charlieplexing method to display the numerals in the Seven Segment display (SSD). SSD is of type Common Anode. Below is the sample Code: #include "18F2520.h" #fuses INTRC_IO #use delay(clock=1000000) #use fixed_io(b_outputs=PIN_B4,PIN_B5,PIN_B6,PIN_B7)
I need hellp am trying digital clock using pic 16f877a interfaceing with rtc 1305 and seven segment leds please give source commend and how to flash pic using in circuit serial programing,......................
Here is my code. This project is thermometer that read temperature from LM35 analog pin using ADC. Code for reading temperature is good and working as need to. My only problem is displaying this temperature. I am trying but I can not find what is wrong. One more question, should I leave COM on ULN2003a connected to 12V or this pin must be unconnec
ULN2003 symbol is shown as if the 7 channels were inverters, but they are in fact open collector Darlington drivers. It is a relay driver with built-in free-wheel diodes to take care of the voltage that comes from inductive loads when they turn OFF. ULN 2003 inputs are 5V TTL level logic, and require 1mA to 1.35mA drive current from the PIC wit
Hi I wan't to control around 100 RGB led (not an led matrix) and need to obtain different colours. Now I am trying the multiplexing by switching the common anode of led using a ring counter and applying the 3 channel PWM from MCU. But for me, I cannot sacrifice the led brightness, I want maximum brightness. (...)
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One possible option is the use of a Port Expander or Shift Register. 6 Digits 7-Segment led multiplexing using a Shift Register The port pins of a PIC can only be configured as input or output, not bidirectional, however the direction of a port pin can be ch
You can see Dot Matrix 8x8 or led 16X8. This is for PIC, you can see the logic to multiplexing and shifting character.
The only drawback in your setup, if any is less brightness from led display which can be managed by using more current drive and using high brightness displays. Two 8 bit ports will be needed leaving enough i/o pin for doing rest of the job.
hi can anyone help me out to solve the issue in multiplexing 7 seg led using pic 16f83.... its a 10min timer counts from 0 00 to 9 59 i got output but the numbers are fluctuating... i attached code and proteus design file....
take a look at microchip application note AN529 it explains multiplexing the led displays, to use less i/o ports than you do ... it is for an older pic 16c54, but the principles are the same with a 16f877 just read the app note and you will learn how to implement your
hey! guys i wanted to use the timer 2 of 8051 to use it as the multiplexing delay for seven segment led display. So guys if anyone of u know how can i use timer 2 of 8051 please give the pseudocode or C code or assembly code will work too. thanks
hi , any one know how to write 4 digit 7 segment led display with multiplexing approach for pic18f2480 plz guide me regrads R.Anandaraj
Hi i want to use a pic microcontroller to control an array of 50 leds. I'm using two ULN2803 ICs to control the anode and cathode of the leds but i'm having problems with my schematic because ULN2803 is a NPN transistor array and i can only sink the voltage and not supply it. Is there any PNP array IC? 66524 This i
Hi, I'm building an led display from a group of 5x7 matrices. I'm building it in stages as I have got to grips with PIC programming, shift registers, multiplexing etc. My next challenge is understanding how to power it though, and I'm having no luck finding anything to help me on the web. I will be running about 10 5x7 matrices, lighting them a