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Questions tagged [timer]

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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timer interrupt on STM32F303

I'm kind of a newbie so excuse me if this is a beginner's question. tried to find an answer but couldn't find one. I'm working on STM32f3Discovery eval board, with the stm32f303vc on it. The code ...
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2answers
2k views

How to configure STM32F4s TIM1 and 8 for PWM

I have configured timer 4 for PWM with following code and connected LED to the configured pin. It is working. ...
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31 views
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1answer
46 views

Help using a 555 timer to increment counter that needs to be pulled low

I need a little help with a project. I'm very new to building circuits. I have this NE555 duty-cycle pulse frequency adjustable square wave generator module, which I have connected to a 12V DC source. ...
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81 views

PIC timer1 interrupt never occurs

I am trying to use timer1 interrupt on PIC18F26K83. I use Micro C as compiler. So I set my timer for 30 ms and after that 30 ms, it is supposed to enter an interrupt and light the LED. But it never ...
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1answer
74 views

One led is blinking too frequently using the hardware timer (stm32f103vdh6)

i recently started my internship using embedded C and i'm having some trouble with one of the tasks: Two leds should be blinking at 1Hz, one using the hardware timer, and the other one using the RTX ...
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2answers
920 views

What does TIM_OCMode do on STM32F4?

I'm making locked antiphase drive for motor control on STM32F4 board. Im configuring Timer4's 4 channels to be in pairs, ch2 inverse of ch1 and ch4 inverse of ch3. Each pair will control its own motor....
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22 views

How is trigger initially higher than vcc/3 in 555 monostable timer?

I get that the trigger must be lower than vcc/3 in order for the comparator to show '1'. But initially how is the trigger higher than vcc/3? In some text it says trigger is initially vcc and so ...
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30 views

Switching timer delay, non accumulative

I am trying to build a 555-timer that delays the switch of an input signal, both ways. When input goes high there should be a delay before output goes high, when input goes low there should be a delay ...
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50 views

How to disable timer on MSP430?

I am new to the TI MSP430G2553. I would like to send a PWM signal like in this picture: (Image source: Adafruit - Understanding Infrared Signals) However I can't do that, because I don't know how to ...
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1answer
374 views

power on power off pulses to two seperate controllers

I would like to request a circuit where a 500 ms pulse is sent to one rail when 12 volt power is supplied and another 500 ms pulse is sent to a different rail when power is turned off. 555 is the way ...
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1answer
55 views

Calculate Prescaler value for PIC16F877

I am trying to figure out if there's a way to calculate the prescaler value for Timer 0 on the PIC16F877. I've looked at both parts of Microchip's tutorial on timer 0 and some other tutorials: PIC ...
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1answer
2k views

STM32F4: How to get data from multiple channels sampled from a single ADC?

So I have searched everywhere for a solution to this problem but I can find anything. I have three channels connected to ADC1 of my STM32F446ZE-nucleo and I want to ...
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1answer
34 views

Timer capture STM32

I have some questions about timer capture in the STM32. Is it possible to capture a digital signal? Like this: Actually, I'd like to know how many clock ticks between rising and falling edge, in ...
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1answer
42 views

How to make 555 timer output fall

I am using a 555 timer in the monostable configuration, which means that when I send a pulse to the trigger pin, the falling edge will make the 555 generate a high pulse on the output for some time. ...
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1answer
287 views

Stm32F103 DMA TIM1 - Load 50% of period.

I wrote a code using DMA with TIM1. In DMA buffer i load diffrent periods and send to ARR Register. How Can I change a Pulse of PWM to 50% from Dma buffer ? ...
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2answers
256 views

8051 baud rate calculator using 16-bit timer for software UART timing

I'm making a project in which pulsed laser beam data is sensed through many optical sensors (one sensor per port pin), so essentially, I'm going to be making 4 UARTs to sense this. Currently I am ...
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1answer
74 views

Need help to identify this timer

This device is installed in our electrical panel which act as a timer to control the on/off operation for our LED billboard outside my office. I searched around the device for the brand and model it ...
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26 views

touch switch time problem

I was looking for a way to make a touch touch switch and i found this circuit on the internet but the problem is , it goes off automatically after few seconds is there any way that i can control it ...
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1answer
138 views

Please help me understand this bjt set up works

This is part of an automotive timer (NOT a 555!) that we have at work. Because I'm extremely bored I'm challenging myself to understand how this one operates. I've spent about 1.5 weeks with tutorials,...
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1answer
26 views

ATMega328P Timer Problem in Proteus

I have an ATMega328P microcontroller, and I'm learning how it is programmed. I wrote an example for Timer0 and uploaded it into the microcontroller. It works and a led blinks once a second in while. ...
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3answers
48 views

555 timer and biasing

Why is it that op-amps used as ICs, such as LM741 require a +Vcc and -Vcc for biasing whereas there is no -Vcc for a 555 timer? What determines the biasing for any IC?
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1answer
33 views

producing a continuous sound using a timer

I'm looking to produce a pure sound on one frequency to be played via a timer to come on at intervals over a six week period. this is for an undergrad dissertation. would an arduino work and could it ...
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1answer
35 views

monostable 555 timer - buzzer motor and pulsing

I need this circuit to pulse an LED while running a buzzer motor for an adjustable period RV1 and C1 should give me 1 - 5s of pulse, while RV2 and C2 should adjust the LED ramp times The LED will be ...
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1answer
489 views

Control a 12 v circuit using wall plug 220v ac timer

I want to use a standard supermarket 220v ac timer to switch a 12-volt circuit. I was thinking about letting the timer run on the outlet, and just desolder the relay separating it from the ac, keeping ...
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1answer
115 views

How can I use the component CD4538 or a 555 timer on Multisim?

How can I use the component CD4538 or a 555 timer on Multisim for a delay of 1 second ? I want both of the nor gates to be 1 for roughly 1 second when the output of the op-amps is either 01 or 10.
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40 views

IoT wireless solenoid circuit

I am a Newbie and I do not have a lot of expirience. The circuit has been put together from pieces I have found on the internet. My goal is to develop a reliable wireless solenoid circuit to water my ...
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1answer
43 views

Using SysTick_Handler in mbed LPC1768 project

I'm trying to use SysTick_Handler in a project which uses the mbed libraries and RTOS, however on compilation, the following error is returned: ...
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1answer
377 views

STM32405 ADC on Update Event of Timer 1 or 8

I'm not sure what I should be asking for because some of the terminology is confusing to me, but what I'm trying to do is use the two motor timers (TIM1 and TIM8) on the STM32F405 to sample BEMF on a ...
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3answers
91 views

Minimal components for timer relay

A 5V LED should run for a predefined time period once a button is pressed. The LED should be illuminated for the same duration as the button is pressed, but only once the button is released and ...
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0answers
36 views

PIC I2C clock related problem

I am trying to make an I2C communication with a device by using PIC18F26K83. I use 8 MHz MCU clock. While trying to set I2C clock these options: Use 8 MHz MCU clock & HFINTOSC for I2CxCLK ...
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2answers
68 views

CD4060 and 74HC4060

I am making a clock timer for an analog LED clock with ICs 4060 and 4027. The clock signal is going to drive some 4017s. Supply voltage would be from 5V to 9V. My online supplier site shows two 4060s- ...
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109 views

STM32 Input capture PWM frequency measurement problem using HAL

I'm trying to measure time passed between two external interrupts generated by rising edges of a PWM signal (generated using a IC 555 timer). Point is to determine the frequency of the signal. I'm ...
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2answers
361 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 ...
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2answers
536 views

if(){} else{} if(){} VS if(){} else if(){} in PWM control [closed]

I'm using timer0 and a gpio pin to generate a 300Hz PWM signal on an ATmega2560. The details if you care: F_CPU=16M, timer clock prescaler /256, count_max=208 The frequency changes depending on if I ...
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1answer
116 views

Delays using Timer in stm32

I am currently trying to achieve delay of 1 uS using timer in stm32 for my application purpose. SYSCLk is set to 16MHZ LSI and define same for timer clock. Timer used is a 16 bit timer. The logic I ...
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29 views

Keypad changing ports for usage of Timers

I want to use timers of ATmega 32 ( PD4 and PD5 ) for pwm mean while i'm using Port D for keypad the available ports for me is PA7 and PC7 i want to know how can i change my code of keypad init. ...
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3answers
2k views

Momentary-Pushbutton Latch Switch with off delay?

I am trying to construct a latching circuit with a 1-2 minute shutdown delay so I can soft start/stop a 240V-5V power supply. I am looking for a momentary push latching (on-off) circuit to switch the ...
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1answer
95 views

Can I use an RC network somehow to allow reading of initial values from jumpers into a micro controller?

I completed a microcontroller project but I want to add a feature where when it starts up, it can read a 4-bit value defined by on-board jumpers (jumper closed = logic low, jumper open = logic high ...
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1answer
88 views

Timer0 in PIC18F26J50

I have a PIC18F26J50 and I want timer0 to output a 1Hz signal on RA6. I'm now getting ~800Hz with my current setup. Clock is 48MHz / 4 = 12MHz on RA6 (if INTOSCPLLO is enabled). Compiler is C18. Here ...
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1answer
34 views

MSP430F2272: Timer B Capture giving shorter measures than the real ones

I'm using: CCS V8 MSP430F2272 DSO-x 2024A Agilent oscilloscope Trying to measure elapsed time between pulses with Timer B, Capture Mode. My square wave source is at 50 kHz and my timer_b clock at 1 ...
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1answer
69 views

stm32f407 timer setup stm32duino

I'm trying to understand how timers work in this board. I want to make a simple led blink after X amount of microseconds and then keep the led on for X amount of microseconds ...
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2answers
135 views

Why isn't my 555 cascading timer working?

I've made a 555 cascading timer. First stage is approx 90 seconds, second is 30 seconds. The first two led's light up in sequence as expected, but the 3rd doesn't light. I've checked all connections. ...
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1answer
93 views

Aircraft Starting Mockup Display With Buzzer Question

I am stuck in the middle of building a circuit for an aircraft starting mockup that will train our students to correctly start the aircraft without accidentally re-engaging the starter and thus ...
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1answer
101 views

LM555 timers for control of a secure door

I will explain existing hardware followed by my desired operation thereof. I have a security door the controller of which has failed. The door has four electronic deadbolts. -- A) Two open ...
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0answers
12 views

In PIC18F4550,But CCP1 Compare Interrput using Timer1 is not working in Relaese Mode but works if use debug mode with pause & Start

I am using PIC18f4550. I am using Timer0 for time keeping which alone works fine. I have tested CCP1 interrput using TImer1 for pulse generation. It also works fine. When I mergred Timer0 time ...
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1answer
93 views

Speed limiter - turn off a motor if a fixed speed limit is exceeded

I want the cheapest, most basic method of turning off the motor while an electronically assisted vehicle is moving at over a certain fixed speed. I don't need to measure the speed other than it being ...
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1answer
47 views

Circuit turn on delay question

Check schematic below, On power on, I want to create a delay when the relay turns on of about 20 seconds. Once its on, it stays on until the power is cut. Timing accuracy is not important. Now I could ...
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5answers
102 views

Will this 555 circuit prevent a car from disconnecting power to the radio when starting?

To start with I'm a little rusty with electronics, I haven't done much in 20 years and it was only a hobby back then. In my car I have a head unit with a touch screen which relies on software to run ...
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2answers
54 views

percision timing ratio of multiple lights blinking with different durations and intervals

I'm learning a lot of this as I go, my background is mostly in programming. I'm trying to setup a timing circuit for two sets of lights going into a model, and am trying to determine the best way to ...