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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0answers
23 views

STM32 - Multiple channel PWM input

I am using an STM32F405 based board , (OpenPilot revo ) to receive PWM signals from a joystick receiver . i have to xapture 5 PWM signals using only two timers , the timer 8 and the timer 12 . I've ...
0
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2answers
45 views

Designing a simple pulse generator

I read in many tutorials that the inner clock in a micro controller are less accurate (%10) than the external crystal clock. When I generate variable frequency pulses by using a micro controller does ...
2
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3answers
94 views

How are timers adjusted in a micro-controller?

In a 555 Timer the resistors and capacitors determine the frequency and the duration of the timer pulses. How is this actualized in case of a micro-controller timer?
0
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0answers
48 views

Power micro LED's from 5 Volt USB

simulate this circuit – Schematic created using CircuitLab I'm working with this set of LED's: Link here: 30 Ft Led wire I measured the draw for the entire string at about 170 ...
8
votes
4answers
952 views

555 timer: how to set values to take an hour

I'm new (and novice) in electronics. I came to seek your knowledge to see if someone can help me with a very basic circuit. It is a 555 chip, which should light a LED (for about 1/2 second) every ...
1
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0answers
21 views

Not entering ISR for timer 4 in stm32f4

I have coded for Timer 4 in a STM32f407vg discovery board. But while debugging the control is not entering the ISR. Please find the code below and help: ...
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1answer
75 views

STM32F4 Timer accuracy

I'm working with an STM32F4 Discovery board and I've come across a bit of unusual behavior that I'm hoping someone can explain the cause of to me. My goal is to configure a timer to trigger an ...
0
votes
0answers
39 views

Using timers on an Arduino Mega 2560 [migrated]

I'm an amateur and I wish to use timers in my project. I'm using an Arduino Mega 2560 with a touch-sensitive screen with six DS18B20 temperature sensors and a DS1307 RTC (real time clock). I would ...
2
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0answers
51 views

STM32F103: not working USB when I turn on the timer

In my project the USB works, if do not use the timer 2. As soon as I enable the timer, the USB is not defined on the computer with an error -71. I use libopencm3; debian; gcc arm; what is the ...
1
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2answers
122 views

555 as a Schmitt Trigger and an ON delay timer?

I've scoured the internet trying to find this out to no avail. I would like to use a 555 timer to produce a Schmitt trigger with an ON delay of 20-30 seconds. Is this possible? Or will I have to use ...
0
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0answers
50 views

MSP430 PWM Dead-Time

According to the internet, the MSP430 has no hardware implemented to maintain proper PWM dead-time as the PWM duty cycle is modified. Apparently (and also according to the internet) this feature can ...
2
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2answers
117 views

Is there difference between Timer vs Counter in ATmega328P?

Is there difference between Timer vs Counter in ATmega328P? Or is it the same thing?
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1answer
37 views

Clock / timer activated 2 second voltage timer for wiper motor project

Ok, I need a 12 volt voltage timer using clock or timer for a wiper motor. I am working on a project in my garage. Simply put, I am wanting to use a wiper motor that will open and close a spring held ...
2
votes
3answers
78 views

Crystal or Crystal Oscillator for time sensitive device

A device that I'm working on is controlled by ATmega328P microcontroller. This will be some sort of a watch, therefore I want it to be as precise as possible. For instance if left to run for a whole ...
1
vote
2answers
90 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.
0
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3answers
163 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) ...
1
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1answer
113 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: ...
0
votes
2answers
88 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
59 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 ...
0
votes
0answers
67 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
83 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 ...
1
vote
1answer
36 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 ...
0
votes
1answer
287 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
168 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
93 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
97 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 ...
0
votes
1answer
307 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
132 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
398 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
78 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
votes
0answers
155 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
4answers
173 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
70 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 ...
-1
votes
2answers
210 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
vote
1answer
46 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
votes
1answer
87 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
vote
1answer
108 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 ...
-1
votes
1answer
104 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). ...
1
vote
1answer
74 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
vote
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
63 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
votes
1answer
138 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: ...
1
vote
2answers
186 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
votes
1answer
132 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
88 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
363 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 ...
-1
votes
1answer
362 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
72 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 ...
-1
votes
2answers
188 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
votes
0answers
774 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 ...