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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
10 views

Wiring a switch timer [migrated]

I’ve bought this timer: http://www.pdlglobal.com/data/product_documents/784_installation_guide_document.pdf The wiring diagram is in that PDF. I need help understanding how to wire this up. I’m ...
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0answers
8 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 ...
0
votes
1answer
41 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
82 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 ...
1
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1answer
103 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. ...
2
votes
1answer
26 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
57 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 ...
4
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0answers
1k views

Send out a short signal every 10 seconds to an arduino [migrated]

In order to reduce power consumption, I want to resume my Arduino from standby mode every 10 seconds. For this a hardware interrupt is necessary. Is there such a device that can create a quick impulse ...
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2answers
72 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. ...
0
votes
3answers
37 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 ...
0
votes
0answers
19 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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votes
0answers
34 views

LPC1768 Timer Interrupt at 1000hz

I'd like to generate a timer which executes an interrupt handler 1000/sec. How do I calculate the required prescaler value for this frequency? What would it be in this case? As PLL0's CLK is 100Mhz ...
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0answers
51 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
1
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2answers
72 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: ...
0
votes
3answers
84 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. ...
0
votes
1answer
38 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 ...
2
votes
1answer
61 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
53 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
63 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 ...
0
votes
1answer
44 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 ...
0
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0answers
58 views

PIC18F452's timers and interrupts

The PIC18F452 datasheet explains that it has 4 timers: ...
0
votes
1answer
43 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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0answers
42 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
46 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 ...
0
votes
1answer
54 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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0answers
31 views

Can a timer capacitor be overriden?

So, I'm using a LTC1980 as a backup power supply regulator. But instead of using batteries as a power source, I'm using super capacitors. Their voltage tend to fall below under-voltage threshold of ...
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0answers
24 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 ...
1
vote
2answers
69 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 ...
-1
votes
1answer
51 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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0answers
71 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 ...
0
votes
3answers
86 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 ...
0
votes
1answer
31 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 ...
2
votes
0answers
86 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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vote
1answer
212 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 ...
0
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0answers
18 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 ...
1
vote
2answers
97 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 ...
1
vote
1answer
120 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 ...
6
votes
2answers
206 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 ...
0
votes
0answers
27 views

The first interrupt flag of Timer0 takes longer time than it should be - Pic18f

i am new with Pic programming. I am trying to config Timer0 to perform a 5s delay. I had a little success, however the first interrupt always took longer time (approx 8s), after that it works fine. ...
1
vote
2answers
64 views

__HAL_TIM_GetCounter with STM32F103

I found a lot of tutorial to get counter value from an interrupt timer something like: ...
1
vote
2answers
71 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 ...
0
votes
1answer
48 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,...
1
vote
2answers
36 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 ...
0
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0answers
196 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 ...
0
votes
0answers
16 views

Switching timer delay, non accumulative

I am a real noob at this and I haven't been able to find my answer anywhere. I am trying to build a 555-timer that delays the switch of an input signal, both ways. When input goes high there should ...
1
vote
1answer
74 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 ...
0
votes
1answer
57 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 (...
0
votes
2answers
164 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 ...
0
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0answers
74 views

How to create a pulse using 555 when the push button is released (“dead man” switch)?

I want to make a "dead man" switch using 555, basically 555 will generate a pulse only when a push button is released (you push the button and nothing happens until it's released). Two days of ...
0
votes
2answers
65 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 ...