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
93 views

HAL Uart Transmit Timer resolution 10µs [closed]

Following this Topic that I started Uart Transmit 1µs I want to be able to transmit a value trough Uart each 10µs . My baudrate is 115200,Clock = 84Mhz And as shown in the previous topic,At a ...
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3answers
64 views

Uart Transmit every 1µs Interrupt StM32 NucleoF401-Re

I am using the STM32 Nucleo F401-RE and HAL libraries. I would like to send value through UART to the PC console every 1µs interruption. Actually I want every 1 µs interruption to increment a ...
0
votes
1answer
36 views

Why I am seeing a spike of 9V on output and capacitor in 555 timer

I would like to have high voltage at output initially for a period of time, then low and high ... . But in the following circuit, I see spikes on output (green) and capacitor (blue) for a short period ...
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0answers
15 views

Understanding how to use a counter and timer for a fixed number of counts

I'm going to generate pulses indefinitely with a 555 timer and use have a counter such as the below one count from 0 to 64 or another power of two and convert the output into an analog voltage to ...
-2
votes
1answer
63 views

Help choosing component values for a relay delay circuit

I want to build a circuit that controls a relay with the following specifications: the relay should turn on and stay on for ~60 seconds after the button is pushed the relay should stay on as long as ...
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3answers
76 views

Deciding Timer Interrupt time

I have used timer interrupt in my application, mainly for timing reasons like timeout detection for processes,pulse generation etc, every 1 ms. Now i have a doubt. Suppose in main(), if im doing ...
1
vote
4answers
78 views

Purpose of Resistor - comparator

I am studying this time delay circuit and am curious to know the purpose of the 4.7kΩ resistor. As I see it, it has no purpose. I've built and tested this circuit with and without it and see no ...
2
votes
0answers
46 views

Implementing periodic sensor data storage and GPRS transmission

I am using custom hardware driven by a TIVA TM4C (specifically, TM4C123GXL) to control a microgrid with battery energy storage, solar panels, four loads controlled by relay, and a SIM900 GSM GPRS ...
0
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2answers
66 views

MSP430FR4133 timer interrupt

I am trying to use the timers on the microcontroller in order to count up to 10us then add 1 to the int timer. I intend to use this in a project I am doing where I count the time between pulses from a ...
0
votes
1answer
48 views

Triggering a LED and interrupting it quickly (with a PIR sensor). What do I need for this?

I'm an artist working on a interactive installation. I'm a beginner in electronics and I'm feeling a little bit lost here, can you help me? I have a 5v circuit with a PIR sensor activating a LED and ...
0
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1answer
51 views

I have this timer circuit. Push and release vs push and hold give me different times

I have a timer circuit which I slightly modified from the one in this link I have an image below of what my circuit looks like. My problem is this: When I push my start button and immediately let ...
1
vote
1answer
53 views

555 autostart counting

In a monostable configuration of the 555: http://circuitdigest.com/electronic-circuits/555-timer-monostable-circuit-diagram I have connected pin2 to the ground all the time. My goal is that once the ...
1
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3answers
85 views

8 bit PICs: timer1 asynchronous vs synchronous operation

The 8-bit PIC family (I'm working with pic18f46k22) offers some timers (timers1/3/5) that can work in both asynchronous and synchronous modes when clocked from an external source. The obvious ...
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votes
3answers
83 views

Servo control using dsPIC33's Output Compare and Timers

I am trying to control a single servo using output compare and a couple of timers. Timer 2 provides the 20ms period and it controls output compare 1 (OC1). OC1 is running in continuous pulse mode, ...
1
vote
1answer
23 views

Circuit that randomizes shut off time to LED's from 1 - 3 seconds when switch is thrown

I have been asked to create a circuit that drives a set of LED's that when switched off uses a random timer from ~1 - 3 seconds before the lights go off. This will be used in a light signal box for a ...
0
votes
1answer
55 views

555 timer digital clock

How would you go about connecting a 555 timer to a circuit with a 16x2 LCD display, which is already connected, to create a digital clock that counts the time? Do you have a sample of how this code ...
1
vote
1answer
59 views

ATmega48PA: can not run PWM on OC0A and OC2A pins

I have some troubles trying to run Fast PWM on OC0A and OC2A pins. The code is the following: ...
0
votes
1answer
51 views

Setting up a counter on STM32F405xx

How do you correctly setup Timer9 (TIM9)on an STM32F405xx to count pulses on rising edge? Is there a special configuration for the pin to the timer outside of this short example? Here's what I've ...
0
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1answer
38 views

555 delay circuit is unsatble

Hello I have built the 555 delay power off circuit by using these 2 guides: home.cogeco.ca/~rpaisley4/LM555.html#30 http://www.electroschematics.com/5963/adjustable-timer-1-10-minute/ I using a ...
2
votes
1answer
61 views

AVR PWM output delay before start

I'm using an ATtiny85 to generate a PWM output (using Timer0 in OCR mode), and this PWM output is being switched on and off at regular intervals. I am finding that when switching on the PWM output, ...
0
votes
3answers
113 views

Is it possible to call Timer ISR when we want it to execute.?

I am using PIC32 and I am doing a timer example. I am using the example of Timer1 provided in microchip documents. My understanding with the timers is when our main program start, timer also start ...
4
votes
6answers
367 views

Calculating Milliseconds using timers in PIC and synchronizing it with DS1307 timing

I have used DS1307 in my project which gives me the values of Hour, Min, Sec but I also need values of Milliseconds. I am ...
0
votes
1answer
93 views

Transistor delay switch equal to a SPDT Relay

I have a circuit I need the functionality of a SPDT switch that is flipped a couple of seconds after power is applied. It is just switching data lines on a USB port so there is no current being ...
0
votes
1answer
53 views

Timers and counters

I have to build a ladder diagram for a system which sounds the alarm if inside 60 seconds after pressing the start button,10 objects have passed.The alarm goes on until we press stop.In the system we ...
0
votes
1answer
85 views

Count pwm pulses on pic

I'm working on PIC18F8722 to generate PWM for 50% duty cycle. I have obtained the PWM and now I need to count the PWM pulse. As per my knowledge we can use timers to generate and count those pulses ...
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2answers
62 views

PIC16 10hz timer with timer1 and 1Mhz clock

I need to increment a stopwatch at 10hz using timer1 on a PIC16F628. The external clock is 1Mhz, supplied by a packaged oscillator (EPSON sg8002db). With no prescaler, the value to set the timer to (I ...
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votes
2answers
70 views

Count external clock pulses for a predefined time interval (PIC16f877a)

I need to count external clock pulses for a predefined time using PIC16f877a. I don't know what to use, whether counter or timer or both. I don't know to use timer and counter modules of PIC16f877a. ...
0
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2answers
108 views

Is it possible to implement a fail-proof watchdog timer in software?

I want to add a piece of code for watchdog timer within my source code so that the board resets automatically when programs hangs. I am using Mediatek Linkit One board.
1
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0answers
50 views

How to set MSP430 Driver Library timerA configurations

I am using MSP430F5529 and MSP430 Driver Library. As you can see, I set upMode timer configuration, compare mode configuration and enabled the initial interrupts. However, timerA interrupt is not ...
0
votes
3answers
124 views

Timer sequence with delayed off and long trigger pulse

Attached here below is the input and out put sequence that I am trying to achieve with a timing circuit. This looks like something that might be achieved with a few monostable 555 timers, but I am ...
0
votes
1answer
79 views

How to calculate the Timer Preload Properly on PIC32MX575F

I am trying to achieve 1 second on a timer in PIC32MX575F but somehow I am not reaching what I want. Some people says I have to look into the the PLLDIV, some other people says I should look into the ...
1
vote
2answers
142 views

Electric Timer With a Micro-Controller

I am trying to replace some electric timers with some sort of a micro-controller based solution http://www.directindustry.com/industrial-manufacturer/panel-mount-timer-154503.html. I would like to run ...
0
votes
3answers
107 views

One month timer circuit

I need to cut a signal wire after one month from it start working. So I am looking for timer circuit that it work by small battery make a short circuit for my signal wire after around ( few days more ...
0
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1answer
76 views

Timer in ATmega2560

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0
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1answer
86 views

PIC32mx Timer5 not working

I am struggling to put my Timer5 working properly. I think I have enabled all the registers but the interrupt never occurs. I already put a break point inside in the FingerprintRun() in the asm("nop") ...
0
votes
1answer
176 views

Bit Banging UART PIC32mx

I am trying to bit banging an UART Port using PIC32MX with timer5 (the only available at this time) but I am struggling how to configure the timer for a Baud Rate of 115200bps. I don't want a flow ...
0
votes
1answer
37 views

Improve a simple “magnetic alarm” with a timer, to extend the ringing time

I've bought this simple "alarm" for a door: Which is internally provided with a reed switch; inspecting the internal circuit using a multimeter, I figured out that when the magnet is placed near to ...
0
votes
0answers
51 views

Proteus and AVR watchdog timer problem in turning off

I created a small avr (ATMega32) controlled circuit that needs to be reset every 1 hour. i used the procedures by atmel that also explained here on SO. The procedure works easily on avr micro, but ...
0
votes
2answers
79 views

Complicated photo-motion-timer switch design?

Here's my scenario: I have an array of 120V LED fixtures that need to be turned on for 10 minutes when the following conditions occur: It's dark out AND Someone walks in front of a motion sensor ...
0
votes
1answer
136 views

Circuit for automatic watch winder

Looking for some advice, completely new to electronics so please bear with me. I am currently working on a project to build an automatic watch winder, I have a 12v 10rpm motor which should be ...
0
votes
2answers
63 views

Unable to set time for PIC32 timers

I am using PIC32MX795F512L. Using Peripheral library to generate timer interrupt. Following is the code I am using: ...
0
votes
1answer
47 views

60hz Astable 555 timer circuit not oscillating

Yet another electronics newbie here :) I have tried to construct a simple 60Hz oscillator using a NE555 timer in astable mode, yet it does not seem to be oscillating. To test it, it has been connected ...
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votes
2answers
69 views

Switch on time limiter for a solenoid - will this circuit work?

Here is the problem i have: there is an electromechanical door chime (just a solenoid with a rod inside, which hits one brass pipe when switched on, and, propelled backwards by a spring, another when ...
4
votes
5answers
523 views

Handmade timer versus IC

Are there power consumption benefits between a discrete timer: astable multivibrator or some other; and an integrated circuit? I have a time dependent circuit in a project and I went looking for the ...
0
votes
2answers
81 views

Timer0 and Timer2 configuration on atmega1280

I want to setup Timer0 and Timer2 to control the intensity of the LED (L) on the Arduino Atmega1280. The frequency has to be 10khz and the duty cycle will be controlled by a switch or using serial ...
0
votes
1answer
49 views

Astable 555 Timer creates longer pulse when just turned on

I have a question regarding the behavior of a 555 timer circuit that I have made. It is depicted below. Now, here is some interesting behavior, I wrote a program on arduino that measures the ...
1
vote
1answer
48 views

555 Timer in Bistable Mode - Unexpected Behavior When Removing Power

I have a question regarding a 555 timer (TLC555CP) in bistable mode. Here is the schematic for the circuit in question. Now, this circuit works as I expect, when I hit the push button attached to ...
2
votes
1answer
55 views

What is difference between choosing OCRnA and ICRn in timer/counter CTC mode in ATMega2560?

I can't find any difference since both function the same role: define the top value so that timer will reset when reach this value. Both have its interrupt flag and interrupt service routine.
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1answer
28 views

ATMega2560 timer not increasing again after overflow

I want to generate waveform with f = 196 Hz using only normal mode. Here is the code I use. Whenever the timer overflows TOV1 is set and PIND0 will toggle. TOV1 is cleared after that and I wait for ...
0
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1answer
48 views

How to control multiple servo motors using two timers?

How can I control several servo motors using 2 timers in an ATmega16? I have searched for "servo bit banging" but no coherent post explains it fully. I found some code but I don't thoroughly ...