Questions tagged [measuring]
Use this tag if your question relates to measuring, eg., via a sensor.
55
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reading pulse count using raspberry pi in python [closed]
I have been trying to read the number of pulse inputs from an external device. The pulse generated is from the arduino uno, and the pin I am using has a frequency of 450hz with 5% duty cycle.
Every ...
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1
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2
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2k
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Frequency counter with external reference
I'd want to use the RPi-pico to measure the ratio between two frequencies, one stable F0 = 10MHz, the other F1 about 14MHz, both externally fed to two GPIOs. 20 bit accuracy is fine. That could be e.g....
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0
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2
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149
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Get Measurements from Battery/Solar Setup
I'm planning a setup with an rpi3b+ and the pijuice hat (battery) and pijuice solar module. It is key to my project that I can access the following data digitally i.e. in the pi:
current power ...
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0
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0
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25
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what is the relationship between worst case execution time (WCET) and cpu utilization of a raspberry pi zero
Assuming the task execution in case of single core processor be sequential, how can we possible relate the WCET of any program to CPU utilization of task and/or core frequency at which the task is ...
0
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1
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372
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Software-Based I2C Cannot Control Clock Speed
I'm using a Raspberry Pi 4B to read pressure sensors via I2C, with Python 3.7.3 and the SMBus library. I ran into the Broadcom clock-stretching bug, so I switched to software-based I2C (brief ...
0
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2
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248
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Raspberry Pi 4b- powerbank measure
I want to power my Raspberry Pi 4b with a powerbank. I know that I need a 3A powerbank.
The question is: How can I measure it? I want to get a percentage of it (which will be displayed over a website)....
1
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0
answers
946
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Raspberry Pico RP2040 - Circuitpython ULAB FFT Frequencies
I am trying to properly perform FFT and calculate frequencies on my PICO using CircuitPython's (CP) ULAB library: ULAB FFT
With traditional Python using NUMPY and SCIPY, this is easily achievable, ...
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194
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How to use Rpi SPI MCP3008 ADC to read visual light LED's transmit and receive signals?
EDIT: Firstly I wrote it a bit confusing way. So let me summarize my problem. This is something like answer to comment bellow.
(1) I am trying to make somethin like visible light communication based ...
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-1
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1
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Can I have different frequencies on different pins on Raspberry pi?
I am trying to configure two pins on Raspberry pi 4 with different frequencies (one being half of the other). How can I do that?
Thanks in advance
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How to list all RPI frequencies' settings?
I've been playing with overclocking in the last 2 days. I'm helping myself with this list.
Yesterday I came across a command which lists all of these parameters and the frequencies which are currently ...
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31
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Cannot change individiual core frequency on Raspberry with cpufreq-set
I used to use cpufreq-set to change the cores' frequency individually on my RPi 3B+, but I noticed that recently I cannot do it anymore. The effect of:
sudo cpufreq-set -c 2 -f 1400000
is the change ...
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1
answer
116
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why frequency output is not constant?
[![I uploaded piscope image and same time output image also for better understanding of issues][1]][1]I am using sample code of Pypi from "http://abyz.co.uk/rpi/pigpio/python.html" to detect ...
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0
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335
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DS18B20 does not have a unique adress in /sys/bus/w1/devices
The problem:
I am trying to use a RW1820 (DS18B20), to display the temperature.
yet it does not show up in devices. Only w1_bus_master 1 appears.
Setup:
Raspberry Pi 4
1-Wire Temperature Sensor ...
4
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5
answers
4k
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Voltage monitoring of battery pack (i.e. before voltage regulation)
I am looking to use four 18650 batteries and a step-down DC-DC converter to power my Raspberry Pi 4. The negative terminal of the DC-DC converter is common for the input and the output.
I would like a ...
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2
votes
1
answer
354
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Direct reading from i2c
I am attempting to increase the frequency at which I read samples from the I2C dedicated pins. I have attempted this through the wiringPi library (C code), from which I reached just about 900Hz. As ...
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5
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1
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996
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Reading Frequencies with Python
hello ladies and gents.
your knowledge helped me a lot until now but now i have a question.
i want to read out the frequency of a 3.3V squarewave. (The unit i want to readout is a capacitive ...
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0
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967
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AC Frequency Monitoring
There are multiple hardware solutions to do amp/current monitoring, but I cant seem to find one to do AC Frequency monitoring. Anyone have a pointer to board that can handle line power and return line ...
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2
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1k
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How can Rpi4B python UART talk to XY PWM Signal Generators?
Currently I am trying to automate a coil winding machine using stepper motors. I wrote a Python code to send frequencies to the stepper motors. But for some reason, the frequencies produced by ...
1
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1
answer
131
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Share data between different
I'm building a floor heating control with raspberry pis. Until now I have two Pis working, one which controls the valves via relays and another which works as "central" with a webinterface to adjust ...
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2
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449
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Raspberrypi unable to read 2000 PPR encoder
I am using a DC motor attached with a 2000 PPR incremental encoder.
I am using RPI to count the number of ticks, my code works fine but I am not able to calculate all the 2000 ticks. Any help would be ...
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1
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122
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Not able count Pulses Generated by PLC
I am using the below code to capture the pulses and count pulses for a specified interval but the output not as what i expected. For every pulse it is giving uncertain value.
The pulse i want to ...
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1
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388
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No thermal throttling in Raspberry Pi 3 model B?
I am seeing that the thermal throttling doesn't work while you read the frequency from:
/sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_cur_freq
And thermal information from:
/sys/class/thermal/...
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1
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281
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Fluctuating SCLK voltage with increase in frequency
Raspberry pi newbie here. As part of my academics i was working on Raspberry Pi 3 B+ , Raspbian OS kernel 4.14.98-v7 and i was testing protocols and i am stuck at SPI.
I am running spidev_test.c from ...
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2
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2
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214
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Measure Volt, Amps, Watt and Kwh of an external 12V system
I saw online some cheap hardware ~10$ that can measure Volt, Amps, Watt and Kwh and display the results on an LCD screen.
I could buy and plug these on my 12V solar panel system to monitor it. (5 of ...
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1
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92
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connect 4 measuring devices output to a raspberry and set a Pin high if value exceed a particular value
I have a special measuring system. Each measuring unit gives PWM output (total 4 outputs). Maximum frequency will be 10Khz (for each output). I wanna measure the frequency of each PWM evey second ...
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1
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86
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Raspberry Pi 2 power consumption incorrectly
Before, i'd a problem about changing governor for my Pi (cpu always stays at 600Mhz in every mode), after doing some tweaking, i'd already make it up to 900Mhz.
However, now i'm using a power-meter to ...
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1
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1k
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Saving measured data to text file
Im using an ADC to measuring values and send them over a socket via the RP, yet I also want to save the values to my RP as I'm reading them. For some reason when I open the text file it only has the ...
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2
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2k
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Count time between two pulses in nano seconds
How can i count time between two pulses in nano seconds by using raspberry pi?
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504
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Energy consumption measurement using ACS current sensor [closed]
I want to build an energy consumption meter using my Raspberry Pi. I have done some research, and determined that the ACS712 current sensor could be interfaced with my RPi for this purpose. I do not ...
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0
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3k
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Is there a way to check out the GPU usage (how busy it is) on a RPi3? [duplicate]
I have a Raspberry Pi 3 Model B and would like to know how busy the GPU gets when I run certain tests to determine whether it would be possible for me to do certain things. I see that the GPU is a bit ...
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2
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801
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How do I connect an S beam load cell to a raspberry pi 3 and then to my Laptop?
I am a university masters student who is currently working with a group of mechanical engineers to built a tabletop tensile and fatigue testing machine. To measure the forces being applied to a sample ...
0
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0
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73
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graph time vs frequency
I am in search of a code which can display the real time graph. I am going to display the microphone input signal in frequency vs time domain. The function that I am expecting is same as the vocal ...
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1
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2k
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code to read live mic input audio frequency
My project is to create a kit to play recorded (music chords) audio file automatically changed with respect to frequency of live microphone input with a certain period.This will help the solo singers ...
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1
answer
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Why is my zero SPI clock frequency different than requested?
Using the SPIdev, I have setup the SPI clock frequency, but measuring the real signal frequency using oscilloscope shows, it differs extremely to the expectations. How is this possible?
spi_fd = open(...
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1
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Does Raspberry Pi 3.0 support HDMI 2.0 standard?
I am not able to see specific protocol version of HDMI (1.4 or 2.0) supported by RPI 3.0. Basically I want to take HDMI 2.0 output from RPI and provide it to my device.
Also can we measure the rate ...
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0
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892
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Incremental Encoder / Frequency
Can anyone help. I have a raspberrypi3 with a photoelectric sensor and a 600ppr encoder hooked up. Everything is up and running, im using pigpio to capture my pulses from the encoder and using the ...
0
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2
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396
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Pigpio belt speed encoder
I'm trying to read pulses from an encoder to measure belt speed. My encoder is 500 ppr. I have approx 2400 pulses per meter and I need to measure speeds upto 450 meters per minute.
Can anyone help ...
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0
answers
81
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Detect voltage using Raspberry Pi [duplicate]
Background
My cottage has a cellar which is relatively humid, so I purchased a system that keeps the humidity at reasonable levels using a set of fans and a dehumidifier. The system runs two ...
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1
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What sensors do i need to use to measure density? [closed]
I want to measure the density of object and I need to get the volume and weight of the object. What sensors do I use to measure density?
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2
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3k
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Vehicle 12v detection or measurement
I have an idea that involves detecting and possibly measuring a 12v feed from a car but my electrics skills are a little limited and I'm using this idea to learn. My understanding is that the 12v feed ...
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0
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2
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1k
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How can I measure current with RPi at high voltage/high current (100-120V / 0-30A)
How could I measure current with a raspberry pi at voltages and currents that can be found inside a typical home's power outlets?
The goal is to create a device that monitors how much energy is being ...
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3
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5k
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Measure RPi3 power consumption without external hardware
I power my RPi3 using a power bank for smartphones, and I'd like to check how much power the Pi draws from it while my project is running.
I don't have any special equipment for power measurement. Is ...
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how to measure length [closed]
I want to measure the number of meters of running cloth off of a fabric roll. So that when I press a button a motor spins a roll of cloth and the fabric is rolled onto a separate roll. I want to be ...
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5
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5k
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How to read values from an clamp-on ammeter with an raspberry pi?
I want to use a clamp-on ammeter (like this one) to detect whether a table saw (230V) is switched on or not. The clamp-on ammeter is meant to be used with a volt meter and has an 1 mVAC / A output ...
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0
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848
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Measure input voltage of Raspberry Pi B+ running Ubuntu
I just learned that a red flashing LED indicates voltage below 4.63V on a Raspberry Pi Model B+. Thus, the Pi seems to "know" about it's input voltage.
So my question is:
Is there a command to ...
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1
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328
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Does RB URF02 ultra sonic sensor give false readings?
There's only 1 raspberry pi shop in my country and he offers only two ultra sonic sensors HC - SR04 and RB URF02 there's a pdf on the pages I linked to for more information. RB URF02 is so much more ...
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6
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3
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28k
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Count RPM/Frequency/Pulses on GPIO ports (Maximum?)
I'm planning to count the RPM of a RC Car which is controlled with a PI B+.
But while planning the question occurs, how to count the RPM. My Idea is via a Sensor, which gives a Pulse every Round, and ...
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2
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2
answers
14k
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Measuring frequency via GPIO
I'm trying to input the frequency of a 3.3V square wave on a GPIO pin as a program feedback parameter. The input frequency range would be 1000 to 100,000 Hz and data polling would happen at 30 Hz. ...
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2
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9k
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How to measure DC current RPi?
I have recently bought a Raspberry Pi, and I would like to be able to measure the current flowing through the circuit in our Greenpower electric racing car. It would also be useful to record this for ...
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2
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1
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235
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Can GPIO measure 3-10ms input spike?
I want to measure speed with one infra gate. The width of the bypassing object is known therefore I could calculate the speed. However the infrared gate would be interrupted only for 3-10ms. I ...
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