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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225 views

STM32F407 - how do I run one motor at a time? Why do they ignore delays..?

I'm a newbie. I'm using an STM32F407 discovery board, and I want to control 6 stepper motors using PWM, especially OPM(One Pulse Mode). Till now I've made 3 stepper motors work using Timer 8 (CH1, ...
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3k views

STM32 Logic level high and low thresholds

I am scratching my head to find what are the minimum voltage for registering a low digital signal and maximum voltage for registering a high digital signal when I configure GPIO pins of STM32 (I am ...
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1answer
99 views

How to avoid this voltage when I turn on the circuit?

What I want to do is an Delay ON, but when I press the switch this voltage pass for a brief moment and turns the led on for a moment. How can I avoid this? Should I put the switch somewhere else? ...
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1answer
149 views

Why can't I route the same signal to multiple pins on an STM32F407?

I have a periodic signal which I want to use as a trigger to two timers - TIM8 and TIM2. When the signal goes high, TIM8 should start running and TIM2 will be clocked once. TIM2 will be configured in ...
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2answers
148 views

Hold Pushbutton for soft latch after X seconds

What I'm trying to achieve is have a momentary push button that must be held for say 5 seconds before latching on permanently. But the button must be held for entire duration or else timer will reset....
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49 views

Suggestions for switching 800VDC converter on/off

I'm stress testing(turning them on-off with load every 300 seconds for 1-2 weeks) the components that we are willing to use. have tested several battery chargers with AC input with using a timer relay ...
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40 views

HM-TRP radio module works at 56K data speed but only in delayed chunks

I created the following setup: I created one circuit in which the PC connects to an HM-TRP radio module via a max232 DIP IC. This circuit for the test is the master to all devices and sends a 16 byte ...
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1answer
214 views

Led as an input photodiode [Arduino AVR]

I’m trying to use a LED as a light sensor(input) connected to a Arduino Nano. I connected the led with the Anode at digital pin 8 (PB0) with a resistance of 56 Ohm and the Cathode at an analog pin A0 (...
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2answers
1k views

TPL5110 doesn't work with NodeMCU

I am using a TPL5110 timer to drive my NodeMCU, in order to keep battery consumption low, but I can't let it work. I have setup the standard circuit for this timer, as below: Whenever I apply power ...
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1answer
1k views

TIM2 DMA configuration for stm32h7

My problem: I can't configure DMA to working properly on Input Capture event. Data doesn't transfered and error occurs. ...
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1answer
1k views

Error setting up timer HAL PeriodElapsed Callback STM32F334R8T

I'm trying to create a microsecond delay function using the STMs regular timer. I wanted to set a timer to fire an interrupt every microsecond and then increment a variable in the call back function ...
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1answer
3k 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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2answers
532 views

Changing frequency of 555 timer with varicap or capacitor

I have created a 555 oscillator circuit where the output is set to have flashing LED light. Now I have a problem when I change the voltage of the potentiometer, the output frequency does not change. ...
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3answers
344 views

Delayed, active low, short pulse for reset

I am attempting to create a circuit using a TUSB2036 usb hub IC that automatically starts when it is powered on. The datasheet states for the inverted RESET pin RESET is an active low TTL input ...
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49 views

What keeps a delay-off timer energized when you cut off the power?

I've come to understand the function of the delay off timer as follows: When it is energized, it instantly changes its contacts. And when you "de-energize" it, it delays for a preset time and only ...
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52 views

Led on for one minute eve if the switch is pressed for more than one minute? [duplicate]

how to make a circuit that when press the switch the led is gonna stay on for one minute and than off even if the switch is still pressed for more than one minute
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2answers
2k views

Timer1 on stm32f4

Im giving a try to stm32 after a long time programming on avr, and seems like im struggling with timer. I want to use timer for handling freezes: ...
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3answers
343 views

Can I use a mosfet as a switch to power arduino?

I have a project in which I intend to use a NE555 timer to turn the arduino on/off on specific intervals. I don't want to use the ne555 output directly because of the current limitations of the chip. ...
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1answer
487 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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1answer
162 views

How to set PWM frequency with high granuality

I want to create a PWM at 100kHz that can have 1000 steps. e.g. when I set CCR1 to 0%, the PWM is off an when I set CCR1 to 499 it should be 50% and obviously at CCR1 = 999, it should be full duty ...
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1answer
99 views

5mm RGB Led built in IC [closed]

Is there any standalone IC do the same job this 5mm Led (standalone flasher and builtin control IC) does?
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1answer
117 views

NE555 Circuit stops working after random time

i finished my NE555 circuit and created some pcbs. After a few attempts i could get the circuit working, and tested it successfully. I placed my circuit between a 12V 1.5Hz square wave signal and a ...
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1answer
55 views

Turn off automatically - timer [closed]

I'm creating a simple circuit and I need it to turn on when I press a button and stay on for the time that I choose on the timer (choose the time on a potentiometer, and it needs to go from like a few ...
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1answer
179 views

Output Compare Interrupt does not work avr atmega

Hey I'm trying to do blinking led using interrupts on 16 bit timer. My atmega model is Atmega168A. Chip clock rate is 12Mhz. Here is my code: ...
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203 views

555 Timer Circuit Simulation Generates an Error

I simulated the circuit below: The expected output is a 50% duty cycle 40 kHz square wave but the simulator (MultiSim) generates an error and doesn't compile. The error message is as follows: "A ...
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1answer
68 views

Obtaining data from parallel port without the “phantom power” problem

After making failed circuits in the past, I learned that the cause is that the parallel port was producing "phantom power" (aka powering the circuit). This is because I plugged my circuit into the ...
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1answer
161 views

LED blinking while loop not working AVR timer 0

It is strange and rare. I am trying to blink a LED at PD0 at 2hz, but it doesn't work. Seems to me that while loop doesn't work at all. I have triple checked the code. what is the problem here? ...
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65 views

Serial baud calculation without using serial interrupt - 8051

Here's the situation. I have a project which utilizes multiple sensors and connects to another unit through standard UART (8N1). Because no data needs to be missed from any device, I made the ...
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2answers
141 views

How does this TLC556 work?

I'm having trouble understanding what the upper part of an electronic metronome depicted in the below schematic does. I already asked about the lower op-amp part in another topic, but I also can't ...
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1answer
391 views

How to pulse an LED for a second with just a single switch, resistors and capacitors?

simulate this circuit – Schematic created using CircuitLab I know you can use 555 and other stuff but I'm trying to do this with just these few components. This circuit is the best that I ...
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730 views

STM32F7 + TI ADS127L01: SPI with DMA circular mode + Timer IC for data ready signal + CRC

I've connected a TI ADS127L01 to the SPI2 of a STM32F746 mcu via SPI2 and Timer 2 Channel 4 input capture for the data ready signal. As soon the data ready signal is captured, the SPI TX DMA (which is ...
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3answers
113 views

Timer interrupt (ISR)

I am using a timer interrupt for multiplexing however my question relates more closely to interrupt service routines. If I set the prescaler and turn on a timer, using the below code I can run code ...
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1answer
224 views

A question about timer resolution and frequency range

In a manual of this data-acquisition hardware the timer output is state as: "One timer output channel(32-bit)" If a timer is 32-bit, what else info is needed to calculate the max and min freq. timer ...
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0answers
98 views

Building a device that lights an LED once a minute [closed]

I'm a complete noob in electronics. I want to build a simple battery-operated device that lights an LED for one second, once every minute. What do I need to buy to build it?
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1answer
1k views

Speed measurement of brushless dc motor with hall sensors with STM32

I have difficulties understanding and finding a solution to find the speed of a BLDC motor. Here is the specs: 3 Phase BLDC with 3x Hall sensors in 120 degrees, 2 pole-pair The image below shows the ...
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0answers
80 views

NE555 monostable timer circuit restart timer when trigger grounded in between [duplicate]

I had made an NE555 timer IC based delay circuit (monostable mode) which keeps output HIGH for 10 seconds when trigger pin is connected to ground momentarily. But what I want is if I ground trigger ...
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2answers
313 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 ...
2
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1answer
902 views

How to calculate RPM, given timer frequency and counter on STM32

on my STM32F103, I use a timer to read rotary encoder Prescaler = 71 Period = 20 Clock = 72MHz Rotary encoder: 2000 ppr Given the formula: TIMUpdateFrequency(Hz)=Clock/((PSC−1)∗(Period−1)) I ...
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2answers
397 views

Detecting DMA overflow in arbitrary waveform generation

I'm generating a complex series of pulses on an STM32F103, essentially as described in the ST app note AN4776 General-purpose timer cookbook, section 5.3. As a quick summary, that means I'm using the ...
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3answers
911 views

__HAL_TIM_GetCounter with STM32F103

I found a lot of tutorial to get counter value from an interrupt timer something like: ...
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2answers
313 views

Electronically adjustable PWM with 555 timer

I would like to create a PWM generator with a 555 timer (like suggested here), but I would like to be able to adjust the duty cycle with a microcontroller. I would simply use PWM from the ...
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1answer
140 views

How to put the value of a Timer in a GPIO port?

I am using STM32L432KCU microcontroller to create a sawtooth signal. My idea is use the timer TIM2 and a R-2R network (Digital to analog converter) conected to some pins in the microcontroller (D0, D1,...
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2answers
42 views

Low Power Timer That Becomes Dead Short at Intervals

(Edited based on feedback) There are two parts to this question: 1) Does the thing I describe below exist already in pre-packaged form, IC, etc. 2) Is the thing common enough to have a name that ...
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2k views

STM32F7 Timer and DMA

I'm currently trying to adapt the example project TIM_DMA of the F769I_EVAL to the STM32F746G discovery board. I'm quite new to STM32 and this might be an obvious error. The code creates a timer and ...
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0answers
37 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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1answer
169 views

How can a flip flop alternate between two clocks, turning one off and the other on and repeating?

I am just experimenting with flip flops and am pretty confused about alternating between two clocks. Right, so I want a pulse to be sent to a flip flop first after 18 seconds and then after 2 seconds ...
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1answer
132 views

STM Prescaler - what happens if it's negative or too big?

I'm using an STM32 The osciloscope is showing really weird stuff and resetting all PWM parameters on STM doesn't help (for another board readings are okay). What happens if I set timer prescaler (...
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2answers
181 views

how to get fractional delay in picmicrocontroller

i am using 4MHz clock for pic18f452. therefore, 250ns is 1 instruction cycle. is there any way to get a delay of 375ns? using timers, i cant define count in fractions. using inbuit delay function ...
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3answers
249 views

555 timer not switching at threshold voltage

This is a 555 timer circuit which is supposed to generate two short pulses, back to back, at a regular frequency. The top 555 is configured as astable to control the frequency. It feeds the first 555 ...
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2answers
162 views

555 astable - frequency not linear with discharge resistor for smaller resistor values

I'm trying to use a 555 timer to create a variable frequency from a resistance, the output frequency should be about 1 kHz up to 300 kHz. I'm using a TS555CN CMOS version, which can oscillate up to 2....