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
58 views

555 timer to work once per day for 30 minutes

I was wondering if I could use a 555 timer to turn on a PI once per day for about 30 minutes. I want to use the 555 because it will take power from a photovoltaic source.
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3answers
61 views

How to make 7-segment display count up ?

I've connect 7447 decoder and 74193 counter as shown in the picture but I have not used 555 timer yet. Is there any way to test the circuit before using 555 ? I've connected the pins (up and down) ...
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1answer
52 views

STM32F1 troubles with a timer

I'm having some troubles with setting up a 1 second timer on STM32F103 mcu. I have set Timer 2 to have a prescaler of 1099 and a period of 65514, so I'm expecting to have a 1 second interrupt rate: ...
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2answers
64 views

Calculating how many times TIMER1 will overflow

I'm trying to understand how to set up an overflow interrupt on ATmega328 TIMER1 to measure a frequency. I'm feeding pin PD4, which is where TIMER1 is externally clocked, with a 503kHz square wave ...
1
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1answer
37 views

Input interrupt pin associated with TIMER1 on ATmega168

A few days ago I came across the source-code for this ATmega168 based Inductance Meter from Dan's Workshop Blog. Below is the code that I believe sets up an ATmega168 interrupt to measure an external ...
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0answers
64 views

Very high speed counter (2GHZ) [duplicate]

I'm trying to build a high speed counter to measure the time delay between two radio waves . I'm thinking of using a MC100EP016A counter which works at a maximum frequency of 1.4 GHz but I cannot find ...
3
votes
1answer
61 views

AVR - ATmega16 - Timer config

Trying to figure out the timer setup in Atmel Studio 6 for an ATmega16 microcontroller. And I just don't get it. I am trying to create a TickCount similar to GetTickCount() Retrieves the number of ...
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1answer
28 views

What's the benefit of Upcounting or Downcounting or Center-aligned mode of timer/counter?

I have done several project (3-4 project) via Timers/Counters but I'm curious to know Why do they have three mode for counting? Also I know that in Upcounting mode it count from zero to 0xff... or ...
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1answer
117 views

How to build a blinking 12V indicator LED light

I attempt to build a blinking circuit using 12V truck light ( like this one: http://www.princessauto.com/pal/en/Tail-Lights/4-in-LED-Stop-Turn-Tail-Light/8126047.p). I have try to build a single LED ...
1
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2answers
146 views

Executing code at diferent speeds, using one timer, and no extra RAM

I was wondering, will this actualy work? (when timer / prescaler set) It saves RAM by not using extra variables. Are the better ways of doing this? ...
2
votes
1answer
86 views

DC current stopper [closed]

I don't really know what I am looking to make is called so I am going to try to explain it. I set up a motion activated light in my room. The lowest time interval is 60 seconds and I am okay with ...
-1
votes
1answer
73 views

Improper functioning of Timer1 in pic18

I'm using pic18f controller and i am supposed to get a delay of 1 sec.I'm using an external crystal of 16mhz and this is the configuration bits that i have used in it.I have configured the timer1 and ...
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1answer
136 views

Can not jump to Timer interrupt function in STM32F4 discoverty

I made a code to call Timer2 interrupt function like this : ...
1
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2answers
123 views

Restart timer for a device

I have a device which needs to be manually restarted (switched off and back on) after every 4 hours or so. I was wondering if there is some device which I can buy or make which does this work for me. ...
0
votes
1answer
138 views

stm32f10x: how to redirect timer output to a given GPIO pin

I would like to programmably send pwm signal to one of the 16 output pins. One way to do this is to trigger interrupt on timer reload and on output comare event, and then to update the corresponding ...
2
votes
1answer
52 views

Using both PWM and Timer2 interrupt in PIC18F25k50

Background I'm working on lead-acid battery charger and experimenting with battery desulfation. I want to draw current vs time graph on graphic LCD and see: how high current spikes I have measure ...
0
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0answers
79 views

STM32 Timer Internal Clock Source

As I understand, the internal timer clock source on the STM32(F4) microcontrollers can be either APB1 or APB2. However, I can't find which timers get which clock. I already found ST AN4013, which ...
2
votes
3answers
109 views

Beats per minute calculator

Basically I want to create a BPM calculator on an ATMega1284. So I have a mic hooked to the ADC already (with potentiometer). I can probably calculate the BPM by getting samples for a while and ...
0
votes
1answer
55 views

Automaticaly switch on/off an (APC) UPS

I need to switch on my APC UPS at 2 AM and switch it off at 8 AM every day. Would like to switch on/off the mains power to the UPS too. I am not an electronics guy, but started to learn and have ...
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votes
2answers
91 views

Delay on STM32F4 Discovery not working

I am trying to make a 10 seconds delay function using STM32F4 Discovery board. Unfortunately, it is not working and I don't know why. I have been two days on this problem. Can anyone help me please? ...
1
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1answer
41 views

Software timers using hardware interrupt

I have to implement a counter for upto 30 minutes on my microcontroller. However the hardware interrupts maximum time is nowhere close to this. So I think I would be using the interrupt and increment ...
0
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1answer
65 views

An adapter for disconnecting the current after a particular period of time

I want to prepare an adapter which will discontinue the power supply after a particular period of time. The time period will be provided manually using a switch. The time periods are: continuous ...
1
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1answer
87 views

Is there a way to avoid an infinite loop and reduce CPU power consumption when using PIC and timer0 interrupt?

I have made a simple program that runs on a P12F629 microcontroller, using MikroC. I need ...
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votes
1answer
97 views

How would I go about pausing the time (for a game on the AVR microcontroller)

basically I need to implement a pause feature in my game (which is a simplified version of frogger) which stops the logs scrolling, and ignores any other input until the character p is pressed again). ...
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1answer
54 views

How to detect which timer interrut called callback when using ASF?

I have a general function, which gets passed among others a timer. It initializes the timer using common callback function: ...
1
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1answer
33 views

Reset the timer counter before the overflow in ATXMEGA64a1

I want to reset the timer before the timer interrupt. In my case, I will use the Mod bus protocol for serial port. I had to reset the timer for each byte sent and send data if the timer reach 3.5 ...
0
votes
1answer
58 views

Delay between timers possible?

I'm using two timers of Pic18 family controller. The Timer 1 is used for RTCC and Timer 2 is used for counting minutes. I have used a crystal for RTCC feature, and for Timer 2 I have fixed a count'x' ...
0
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1answer
97 views

dspic Timer1 Interrupts Occuring Twice as Slow

Maybe I'm missing something here but on a dsPIC33FJ16GS502, I designed Timer1 to toggle a pin at 200 Hz but when implemented, the frequency is actually 100 Hz. I have the following configurations: ...
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2answers
128 views

NE555 timer not working - how to identify the element at fault?

background Im a beginner in the field of electonics, and I have been trying to put together a IR remote control / laser tag system using Arduino Nano. I am using a TSOP4840 receiver and a TSAL6100 as ...
0
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1answer
119 views

Simple question (I guess): 555 timer

I want to know if it's possible to have a push button so that when it's activated, it turns on my 9 volts circuit for 10 minutes and then turn it off. Also, I don't want this circuit to consume ...
0
votes
1answer
80 views

Low power timer circuit for solar tracking

I'm making a solar based device but it needs to be aligned according to sun's position in sky , the whole assembly needs to move around 11 degree/hr. So I was thinking of using a timer circuit (low ...
4
votes
3answers
280 views

Calculating time spent by a function in Microcontroller Applications

I would like to write a simple profiler for my STM32F100VE microcontroller. I have seen that I can include time.h and based on the c standard functions I can use it, but I was confused about ...
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votes
1answer
203 views

How to measure distance using radio waves? [closed]

Have you seen http://www.youtube.com/watch?v=CvZ4_SIAxDY I need a similar circuit to do the same. There are two module. Module A and B. A sends to B and B returns signal to A. How to find the time ...
0
votes
1answer
60 views

555 timer duty cycle

In order to increase the Duty cycle span of a 555 timer above 50% I should connect a diode. the equation of duty cycle without diode is D=(R1+R2)/(R1+2R2) but when I add the diode what is the exact ...
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2answers
155 views

The 555 timer (astable mode)

how can i edit the 555-timer astable mode in order to get a larger span of duty cycles passing by values below 50%? D = tH/T= (R1 + R2)/(R1 + 2R2) this is the equation, by changing the values of R1 ...
0
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0answers
525 views

Calculating a delay of 1 second with a PIC 16F877A

I got a PIC Micro controller with a 4mhz crystal. I established(hopefully right) that 1 cycle requires 1 micro second to complete. As a result to accomplish a 1 second delay, I need to use 1,000,000 ...
4
votes
3answers
615 views

Software delay vs hardware timers

Working with a micro controller, on which exact conditions should we choose between Hardware timers and Software delays on an Embedded Controller? I have seen articles which do emphasize on use of ...
-1
votes
2answers
82 views

Ideas on building a water sensor power switch

I would like to build a water sensor power switch. A device which completes the circuit of an outlet adapter when the water sensor has detected water. I have a very simple idea about this little ...
0
votes
3answers
134 views

How to trigger something once a day [duplicate]

What would be the right thing to use if I want the base of a transistor to be high for 12 hours and low for 12 hours? I ask because I would like to make a circuit that regulates temperature in a ...
0
votes
0answers
70 views

Latch Switch with timer relay

So my basic operation of things are: -A button will be pressed -A timer relay will be triggered and will run a high power motor. -The relay would turn off after a predetermined time. -The button will ...
3
votes
3answers
627 views

Using 555 to generate square signal with fixed duty cycle / variable frequency

I am attempting to design a circuit whose output is a square wave with the following properties: Fixed duty cycle, as high as possible (let's say 99%) Variable frequency, between 0.2 - 20 Hz (I'm ...
1
vote
1answer
198 views

What is the difference between Timer0 and Timer2 in AVR

I'm using ATmega32. This two timers looks very similar. What is a difference between them? When should I use Timer0, and when Timer2?
1
vote
1answer
185 views

STM32 Timer to control GPIO

I'm trying to output a slow clock (4kHz) on an I/O from the STM32F0. I'm wondering what the advantage is (if any) of using one of the timer pins to output this clock vs toggling another GPIO on the ...
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votes
2answers
105 views

Toggling on and off 220V power

I have a 9V 555 timer circuit and I want to use it to automatically turn on and off a 220V water pump. What can I use to connect the timer and the pump? Is there like a transformer or something?
3
votes
2answers
182 views

How can I wake up an ATtiny84 microcontroller at specific time of the day?

I am trying to create an alarm that wakes up at a certain time and does a series of instructions. To set the times that it wakes up, I am going to use the headphone of an Android device to send ...
0
votes
0answers
20 views

556 dual timer to produce a biphasic wave form, and possibly an assymetrical biphasic? for muscle stimulation [duplicate]

I am needing to make a 35Hz biphasic asymmetrical output for a muscle stimulation device. I have a 556 dual timer and am familiar with the 555 timer, but entirely sure how to utilize 556 for biphasic ...
0
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0answers
129 views

STM32F207 timer2 output toggle

I am trying to get clock signal out of timer 2 channel 1 on my STM32F207ZGT6. I wnat to use the compare match to toggle the pin, but nothing I programm seems to get any kind of signal on that pin ...
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3answers
239 views

Can you make a waveform asymmetrical with the 555 timer?

Using a 555 timer how do we output a biphasic square wave instead of a monophasic? Is there any way to make it asymmetrical? If not are there any other devices or circuits to use to make an asymmetric ...
0
votes
2answers
280 views

PIC:how can we get 1 ms interrupt using 16bit timer?

I am using PIC24FJ256GB106 controller.I am setting configuration bit for internal frequency to FNOSC_FRCPLL. I have confusion to this configuration bits that Am i getting 8MHZ or 16MHZ or 32MHZ ? if ...
0
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1answer
106 views

555 timer multivibrator charge and discharge

With this kind of connection I expect 555 to run as a multivibrator. As far as I understand the discharge of the capacitor should be via R2, while charge of the capacitor via R3 and D1. => discharge ...