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.
0
votes
1answer
45 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
votes
1answer
47 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
48 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
vote
3answers
68 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 ...
0
votes
3answers
79 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
22 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
49 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
54 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
49 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
votes
1answer
33 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
57 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
108 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
323 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
88 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
49 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
79 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 ...
0
votes
2answers
58 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 ...
0
votes
0answers
19 views
PIC16 timer0 clock calculations
I'm having trouble working out how to implement a timer using timer0 and a 1Mhz clock on a PIC16F628. I thought it would be like this:
clocks/sec = 1000000
counter increments every 4th clocks so ...
-1
votes
2answers
50 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
votes
2answers
101 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
vote
0answers
47 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
99 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
74 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
136 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
103 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
votes
1answer
66 views
0
votes
1answer
82 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
174 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
34 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
44 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
74 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
112 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
62 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
45 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 ...
-1
votes
2answers
60 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
504 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
71 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
44 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
45 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 ...
1
vote
1answer
51 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.
0
votes
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
votes
1answer
42 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 ...
0
votes
1answer
181 views
TimerA: How to get PWM in upMode configuration?(TI MSP432 Launchpad)
I try to use UpMode timerA configuration on MSP to get PWM with arranged Duty Cyle. So here is my code below:
...
1
vote
0answers
42 views
Only allowing input after x amount of time
I've been given a problem to solve -
When the input is high (sensor), a timer should start which outputs high for 10 minutes (camera active). After 30 minutes, if the input is high, the process ...
3
votes
1answer
111 views
How to reset slave timer in gated mode?
How to make automatic reset of slave timer in gated mode in STM32 mcu?
Summary:
I've done synchronization between 2 timers: Timer#1 is configured as a slave in gated mode, Timer#2 is configured as a ...
-1
votes
1answer
77 views
Can timer2 control the pin “oc0” in ATmega32a?
On a board the input of a PWM controlled device is tied to the pin oc0 of an ATmega32A and it's not changeable (it's a PCB). Timer0 is busy and can't produce PWM to ...
0
votes
1answer
89 views
Help with using monostable one-shot multivibrator?
Above is the schematic I simulate in LTSpice. The input signal is a 8V pulse train with 100us ON time and 2250us period. The signal is fed as an input to the timer 555(NE555 in LTSPice).
I'm trying ...
0
votes
1answer
54 views
Controlling a servo with Attiny85 OCR1B
I currently have a project where I need to control a servo using OCR1B. I already figured out how to use one with Timer0, but I can't use that for this project though.
So, my questions are:
- How ...
-3
votes
1answer
55 views
what IC is typically used in a switched mode power supply for pwm voltage regulation [closed]
So what is used? do they basically run off of a something like a 555?
0
votes
2answers
49 views
Help with timed signal circuit
I need to design a circuit capable of sending an on signal for 5 seconds and then shut off. The circuit needs to be initiated on power input from a usb port (5v ~200mA), and as I said output a few ...
