Circuit to generate a signal a specific time after a trigger event. The timing can be defined by an RC time constant, or by clock pulses from an oscillator.

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2answers
54 views

Adding a sensor to a traffic light circuit?

I am using the current circuit to time a basic traffic light that changes every twenty seconds: However, I've been trying to figure out a way to add a way to detect a car stopping at the light, so ...
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2answers
44 views

Resistors and capacitors calculation for 555 timer circuit

I am new to electronics and I want to try an experiment. I want to use a 555 timer to create an automatic food dispenser for my aquarium (something like opening a small door when the timer has ...
2
votes
2answers
111 views

Timer PIC16 not working.. is it my code?

I'm new here as an OP, but I have been visiting this site for years. This time, just looking at other problems hasn't helped me. Hence, I sign up and just ask! I'm creating a countdown timer with 30 ...
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1answer
19 views

How to put a delay timer on a micro motor small Area

I am trying to put a micro motor basically as small as I can inside of a 1"or so wide tube like a long fishing plug, I am going to put a small prop or propeller on one end. What I need is to be able ...
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2answers
67 views

How to control on/off with multiple LEDs without traditional multiplexing

first post here but I've been doing some research and cant find a definitive answer. Goal: Use some type of voltage-controlled switches in parallel (similar to schmitt trigger) that will accept PWM ...
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0answers
48 views

dimmer on demand

I am trying to make a "dim on demand" for my aquarium (freshwater planted aquarium/shrimps) There are 24/7 timers/dimmer out there, but I have weird schedule everyday. Press an ON button Light ...
1
vote
2answers
70 views

Wrong frequency with Timer1 on Atmega328p in CTC Mode

I want to make a LED blink at a frequency of 0.5 Hz. So, I use an Atmega328p, clocked at 16 MHz, and the Timer1 in CTC mode, which triggers an interrupt every milisecond. Yet, my program, in Atmel ...
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0answers
30 views

circuit for switching on and producing desired high pulse then circuit turn off without using micro controller

i have no prior knowledge about electronics , but i am trying to make a circuit that turns on the switch after 10 seconds and then produce a desired length high pulse say 30 seconds then it turn off ...
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2answers
28 views

Timer Astable with NE555 not getting +V

As a part of my school project I have a timer astable with NE555 and I need to generate a square signal. It has 12V supply and 65% duty cycle normally. In my simulation on LTSpice I get exactly what ...
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0answers
36 views

Problem with timer and capacitor circuit, Repeater

I am Trying to make a circuit in which I am using 2 timers 220V AC and set their time to 4sec and 1 capacitor 3.5uF 400V AC. I have removed the timers from their base so you can understand the ...
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3answers
77 views

how to calculate time for timer relay

In the below circuit of Timer Relay, how I can calculate the time for C1 to be fully charged? please don't use regulator, transistor or any other device I just want to use Resistance and want to ...
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0answers
32 views

Configuring the rate of Timer interrupts for the STM32F4xx Discovery Board

I'm working on a project with the STM32F407 board and Keil, and as part of a larger project I'm working on I need to configure a timer interrupt. Eventually it will run at around 46 kHz, but for now ...
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0answers
22 views

Systick Timer problem

I am trying to use the systick timer to update a variable which stores millisecond elapsed on a STM32F051 in Coocox ide 1.7.8 . I also want I2C and UART communication in my project. I managed to get ...
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0answers
42 views

STM32F051 TIMER2 INTERRUPT PROBLEM

I would like to get TIMER 2 working for stm32f051 microcontroller in coocox IDE(1.7.8) . The problem i am facing is that as soon as I enable the intrrupt for TIMER 2 using NVIC_EnableIRQ(TIM2_IRQn) ...
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votes
0answers
51 views

how to make 30 seconds timer [closed]

I'm trying to make a timer, that powers the small motor for 1-2 seconds, every 30 seconds. I need this to be portable. Can someone help me? the motor I have is using 3 V voltage, also I don't want ...
0
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0answers
53 views

How can i trigger this watering timer manually

I have a automatic watering timer that I purchase from the internet. I'm attempting to hack it into something that I can either trigger from a micro-controller, or sense when the solenoid has been ...
2
votes
2answers
87 views

Best way to sync LED's to light NES figures on a wall clock?

Advice & Ideas needed... Working on a project - a custom wall clock with perler bead NES sprites in the place of the numbers. The figures are mounted to a wood board with cutouts underneath, and ...
2
votes
1answer
67 views

Using XMEGA timer

I want to use the timer in XMEGA to know how long it takes for a function to be done: ...
0
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1answer
54 views

Atmega328 fast PWM (mode 7) of timer 0 not working as expected

I am blinking an LED on PORTB5 using timer 0 in mode 7. The time between blinks is computed as $$ \frac{(\text{OCROA}+1) \times \text{prescaler} \times \text{timerCount}}{\text{FCPU}} $$ ...
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1answer
61 views

555 timer accident

I accidently applied around 5V to the output pin of the 555 timer.The output is zero when I ground the trigger, and an LED connected between 5V and pin 7 will not respond when 5V is applied to the ...
0
votes
1answer
57 views

Variable Timer Circuit w/ Digital Display for Counting Down

I would like to make a timer. The timer will have a 7 segment digital display and will work with a microcontroller of some sort. I would like to be able to put in a time (e.g. anywhere between 0 - ...
1
vote
1answer
47 views

What the output isn't correct when I use a switching power supply?

I have a circuit that it is a STM32F103RET6(Reference Manual) board and one LCD. everything work very well just one thing! PWM! when I use my J-Link debugger to supply the circuit(or USB connector), ...
0
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1answer
87 views

AVR Timer1 OCR1A controls TIMER1_COMPB_vect interrupt!

I was struggling with timer interrupts in my project. I couldn't make it work properly. So I decided writing a simple code and I saw a very interesting case. ...
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votes
1answer
22 views

AVR ATmega644p: can't clear OC0A pin on CTC mode

I made an IR blaster for controlling TV (on and off) based on ATmega644p. I am using Timer0 in CTC mode to generate 38kHz waveform. This is the code: ...
2
votes
1answer
52 views

Understanding PIC32 watchdog timer operation

I'm new to uC development and have been fooling around with the PIC series for about 6 months now. I recently started working with the PIC32 and Microchip's XC32 C++ compiler. I don't know if I have a ...
0
votes
1answer
50 views

toggling a pin using the hardware compare feature of timer1 AVR

This link - says: "In CTC mode, you can also trigger interrupts, but it is also possible to not use interrupts and still toggle an output pin. Using it this way, the functionality occurs ...
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1answer
84 views

Extremely small electric shock device - could this work?

My question is this: Is it possible to build a device which could deliver a small electric shock every hour or so, and to fit this into a standard size ring? I am talking about a small electric shock ...
0
votes
3answers
76 views

sequential leds using op amp

I am trying to design a circuit that has a timing sequence. The timing sequence will be started by a SPST momentary switch. For the first 2-4 seconds a green led will display. When the first timer has ...
1
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3answers
280 views

How to calculate the time of one single tick on microcontroller

I have been in Embedded system for 8 months. I have worked application part more compare with low level. I have basic questions on systems ticks, How to calculate the system tick of Timer, if I am ...
0
votes
1answer
85 views

TIMER0 in PIC18F4550

I am using PIC18F4550 I am trying to generate an interrupt every 1 sec, and by trial and error(i.e. just writing and simulating on hardware ) I am getting interrupt approx to 1 sec. Code for this ...
0
votes
2answers
73 views

Timer for turning LED's on for 4 seconds and then off for about 200 seconds

I want to build a very small, low power timer that will allow several LED's on for 4 seconds and then off for about 200 seconds, then repeat. 4.5VDC. No programming. Help please - thanks.
1
vote
1answer
32 views

Using TIMER 1 without enabling interrupt in C on dsPIC33E

I am trying to decipher a C code in which Timer1 is being used for measuring the period of a digital signal, using dsPIC33EP256MC506. The timer interrupt is not ...
0
votes
1answer
121 views

Stop timer set new value and start again AVR (Interrupt)

I have AVR MCU. I am playing with timer now. What I need ? I have timer counting up with some frequency. In each interrupt I am incrementing variable, and somewhere I need to check value of this ...
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votes
2answers
132 views

How to make a stopwatch timer [closed]

I want to make a simple stopwatch timer using simple materials such as a breadboard, a couple of IC's (integrated circuits), wires, resistors, capacitors and transistors. Is it possible without doing ...
0
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0answers
35 views

STM32F205VC - What causes this short impulse in one-pulse mode of TIM1?

Hi! Why am I seeing this short impulse? This is my code: ...
-3
votes
1answer
79 views

AVR 60Hz periodic interrupt [closed]

How can I configure an AVR microcontroller timer to generate periodic interrupt events at 60 Hz rate, using 14.745 MHz system clock?
2
votes
1answer
303 views

STM32: Timer interrupt works immediately

This is code for timer in my project on STM32F429: ...
0
votes
3answers
122 views

Delay function using timer/counter 1

i have made a function called _MY_Delay() which use 16bit timer/counter1 in ATMEGA16 , and used this function to blink a LED . the problem is i didn't work and i don't know the reason , here is my ...
0
votes
1answer
57 views

Time delay relay

I am having trouble figuring out what kind of time delayed relay I need for this circuit or if anything will work even. It is used to keep a dome light on for a few seconds in a vehicle after the ...
1
vote
0answers
48 views

PIC12F simulator: Why isn't the oscillator running?

I have written firmware for a PIC12LF1572 that I am testing in the MPLAB X simulator. The program runs and correctly responds to stimuli, except when it needs to wait for a timer interrupt. After a ...
0
votes
1answer
102 views

How do I build a DC time out circuit that stays off until power is toggled?

My girlfriend bought an LED faucet that is actuated when you turn the water on and is powered by a battery pack of 4 AA batteries (2 wire out). However, when the water is turned off, the slope of ...
0
votes
0answers
147 views

Using Pic18F timer for external pulse count assembly code

I am new to using a Pic18f2550 micro-controller. I have been searching for examples on how to setup and use the 16 bit timer Tmr1 and Tmr2 to count the number of pulses from an external motor opto. ...
0
votes
1answer
104 views

STM32F051R8: PWM timers don't work?

I'm working with MB1034B discovery board and STM32F051R8 microprocessor. I'm trying to output some PWM pulses using hardware timers. I use this tutorial (for STM32F4xx): ...
0
votes
1answer
53 views

Measuring time using an STM32F407VGT6 microcontroller

I'm using a custom board for charging and testing batteries. Its 'brain' is an STM32F407VGT6 microcontroller. I'm developing in Ubuntu (14.04.2 LTS), using ChibiStudio (ChibiOS/RT 3.0 development ...
0
votes
0answers
19 views

program stops in non maskable interrupt when initializing time interrupt

I am using RX62N microcontroller and am new to it. In this i was trying to blink the led using interrupt(compare match timer) but after the initialization it always goes to the non maskable interrupt ...
1
vote
1answer
91 views

PIC18f4550 Timer setup for 1sec Interrupt

I want to generate Interrupt(on PIC18f4550 using TIMER0) every 1 sec but by using the following code interrupt is generated after every 6 secs. ...
1
vote
2answers
118 views

Turn a METAL HALIDE BULB On/Off in 1 minute Intervals?

OK, let me 1st give you some background information. I need to generate 40,000 lux of light in an indoor environment (in a area of around 5 feet by 3 feet) and I need the ability to turn the light ...
3
votes
3answers
85 views

Help Trobleshooting my first solderless circuit on a breadboard

I'm working on my first project from the book "Electronics All in One for dummies", chapter 6, book 1. I work through all the instruction but I cannot make the LED blinks. The circuit diagram is: ...
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3answers
199 views

How to turn a switch on/off repeatedly in 1 minute intervals?

I have a light bulb plugged into an outlet and I need to be able to turn it on and off again and again in 1 minute intervals for a period of 10 hours per day (a total of around 600 on/off events per ...
2
votes
2answers
164 views

On STM32F4xx: Can I trigger a timer by itself so it goes through a list of periods updated from an array?

I need things to happen at precise (down to the clock, ~5.5ns at 180MHz) periods of time based on a list; let's say 5 periods of 444444, 555555, 666666, 777777 and 888888 timer clocks (obviously a ...