Questions tagged [measuring]

Use this tag if your question relates to measuring, eg., via a sensor.

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1answer
44 views

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 ...
2
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1answer
37 views

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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0answers
58 views

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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1answer
277 views

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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1answer
36 views

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 ...
0
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1answer
132 views

Raspberrypi unable to read 2000 ppm encoder

I am using a DC motor attached with a 2000 ppm 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 ...
1
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1answer
62 views

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 ...
0
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1answer
54 views

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/...
0
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1answer
108 views

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 ...
2
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2answers
52 views

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 ...
1
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1answer
48 views

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 ...
0
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1answer
46 views

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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1answer
658 views

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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2answers
616 views

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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1answer
317 views

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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0answers
2k views

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 ...
1
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2answers
553 views

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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0answers
68 views

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 ...
0
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1answer
2k views

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 ...
1
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1answer
833 views

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(...
3
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1answer
5k views

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 ...
0
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0answers
787 views

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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2answers
291 views

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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0answers
73 views

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 ...
1
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1answer
646 views

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?
0
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2answers
2k views

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 ...
0
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2answers
700 views

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 ...
16
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2answers
4k views

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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1answer
928 views

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 ...
4
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5answers
3k views

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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0answers
417 views

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 ...
0
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1answer
321 views

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 ...
7
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2answers
24k views

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 ...
2
votes
1answer
10k views

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. ...
2
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2answers
8k views

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 ...
2
votes
1answer
212 views

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 ...
0
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1answer
526 views

How to measure mains frequency safely via GPIO

I would like to measure the mains power (120vac/60hz) to know precisely when the voltage drops to 0, but in a safe manner for the pi - one solution would be to use a high-value resistor bridge that ...
1
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1answer
141 views

Mesure weight using force [closed]

Is it possible to use this force-sensitive resistor to measure weight between 10g-5kg(0,4oz-176oz)?
1
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1answer
9k views

Are my GPIO ports not working?

On my Raspberry Pi, I tried to do some experiments with GPIO, without success. Measuring the voltage between GND and GPIO11, for example, always helds a result of 0. I am using /sys/class/gpio ...
26
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4answers
49k views

How do I measure the current power consumption?

Is it possible to measure (with software, like PowerTOP) the Pi's current power consumption, on my Raspberry Pi?
8
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3answers
8k views

How to detect whether there is voltage between two points via GPIO?

I'd like to detect whether an external device is switched on or off. I found two pins where there should be 5V between in the first case, but the voltage may vary a bit and I don't wont to break the ...