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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1answer
28 views

Single motor + Timer. Lift and reverse hand. Single joint robot arm

I need help trying to design a single jointed robot arm that will lift to almost flat on a wall, back down to a right angle position on a timed sequence, repeatedly. It would pause for a few seconds ...
-1
votes
1answer
54 views

How to power 3 different AC circuits without crossing them

I have 3 zones in my house with 3 24v thermostats. These thermostats tie into a zone relay that triggers a 120v line to each circulator to heat that area of the house. I need a way to have my timing ...
1
vote
3answers
62 views

Error generating 1 sec delay using timers in PIC32

I have a PIC32MX795F512l and because XC32 doesnt provide an inbuilt delay function, I am using ...
1
vote
1answer
47 views

How to wire this delay relay switch

Hello I recently bought this item at ebay and I am not sure how I should wire this. I will power it with a 9 volt battery and the relay will power a pump, this is how they at ebay show how I should ...
2
votes
2answers
53 views

555 timer circuit error

I have recently built a circuit with a 555 set in monostable mode which was supposed to turn on three bright LEDs for 51 seconds when a button was pressed.The button was connected with some long ...
0
votes
4answers
182 views

How To Hold Power ON For Some Time Without Using A Microcontroller or 555?

This is my first question here, so I'm hoping for help. I'd like to take a Momentary event and use it to turn on a device (LED, for starters to model the concept) for a minute (give or take) at a ...
4
votes
1answer
148 views

Interrupt never fires

I'm new to embedded and I've been struggling with this for days. I just don't understand why this doesn't work. I'm using an ATxMega128A1. I want to use a timer overflow interrupt to left shift a bit ...
0
votes
2answers
172 views

How to blink LEDs with different frequency?

I have a pic32mx and three LEDs. [datasheet pic32mx] (http://hades.mech.northwestern.edu/images/2/21/61132B_PIC32ReferenceManual.pdf) I need a function that gets the number of LEDs and frequency, and ...
0
votes
1answer
39 views

PWM of Diaphragm pump

I'm pretty new in this area so sorry if this question seems foolish. I have a 12V 20Lpm Diaphragm pump that draws around 18 Amps. I'm using it on a home built herbicide spray system to help deal ...
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0answers
41 views

Controlling a servo motor on an LPC2103 microcontroller

I'm still a beginner on deep embedded systems development. I would like to know how to control a servo motor without using PWM, since I didn't actually learn anything about it on my classes and I'm ...
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votes
2answers
74 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 ...
0
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2answers
83 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
129 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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votes
1answer
20 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 ...
1
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2answers
74 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 ...
0
votes
0answers
50 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
82 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 ...
0
votes
2answers
35 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
43 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
101 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 ...
1
vote
1answer
48 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 ...
0
votes
0answers
35 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
67 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
votes
0answers
57 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
97 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 ...
3
votes
1answer
119 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
votes
1answer
78 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 $$ \frac{(\text{OCROA}+1) \times \text{prescaler} \times \text{timerCount}}{\text{FCPU}} $$ ...
0
votes
1answer
65 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
93 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
48 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
votes
1answer
215 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. ...
0
votes
1answer
36 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
93 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 ...
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votes
1answer
62 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 ...
1
vote
1answer
120 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
86 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
vote
3answers
363 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
104 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
84 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
43 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
193 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 ...
-5
votes
2answers
164 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
51 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
89 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
598 views

STM32: Timer interrupt works immediately

This is code for timer in my project on STM32F429: ...
0
votes
3answers
222 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
71 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
55 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
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1answer
133 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 ...