Questions tagged [analogread]

A standard Arduino function for detecting the voltage on an analog pin via ADC.

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-2 votes
1 answer
87 views

Using 1.1Vf to read stable battery voltage and sensor voltage

After several tries, i was successful with reading stable battery voltage using internal voltage reference of 1.1v, now the issue i face is that i cannot read stable sensor voltage, could you please ...
-1 votes
1 answer
101 views

Reading constant battery voltage and using the obtained value in sensor formula

there i am working on a project in which my system is connected to 3.7v~4.2V lithium battery, I have to read constant battery voltage irrespective of the current battery voltage and to do that I am ...
-1 votes
1 answer
77 views

Carbon dioxide sensor MG 811

I am using MG811 carbon dioxide sensor with ESP8266 module. CO2 values is being read inside closed room. The value comes around 400 ppm. Using CO2 generator does not make increase in reading. Checked ...
-2 votes
1 answer
60 views

600VDC measurement with Arduino (voltage divider)

I need to detect quick (~200ms) voltage drop, so I am thinking of making an oscilloscope with Arduino. Problem is - can I reliably read 600V DC voltage and what resistor values should I choose for ...
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0 votes
0 answers
55 views

How to work with a pulled high input pin where it needs to read a value from an analog sensor?

I have a small ESP32 module, that has some in-built features, like a TFT, and has few available pins for general use. It has some input only pins (GPIO36 to 39) that are used by buttons soldered in ...
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1 vote
0 answers
29 views

Code not checking for updated sensor values after connecting to firebase?

I am using a project with an MQ138 sensor and want to push the real time sensor reads to firebase. Currently, the wifi/firebase part and sensor part work fine separately. The code connects to wifi and ...
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0 votes
1 answer
50 views

Arduino Mega, 6 push buttons for each analog input (A0-A9) - closing one results in reading by other

On day to day basis I'm more of a high level programmer, with little electronics knowledge, apologies in advance if I lack some nomenclature or basics. I communicate with my Arduino Mega via firmata, ...
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1 vote
1 answer
53 views

IF statement to run even if the requirement isn't met anymore

I have built a flasher for the headlamps on my race car. Whilst it works when I hold the switch down, if I release the switch and the circuit is closed my IF statements requirements are no longer met ...
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0 votes
1 answer
74 views

Arduino Uno Analog pot values are not smooth

I have tired Arduino smoothing example but mine analog value are not staying constant even when I don't rotate the potentiometer. I am mapping the values from 0 -> 1024 to 0-> 100. I have tried ...
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2 votes
1 answer
115 views

Measured voltage higher than AREF

What happen when a voltage measured by analogRead() is higher than AREF voltage? Example: AREF = 2.5V AO = 3.2V What is the maximum voltage ?
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1 vote
2 answers
151 views

Why analogRead's value decreases when I decrease the value of resistor?(I use digitalWrite(high) to positive terminal of resistor)

Basically, my circuit contains only 1 resistor(like the basic LED circuit). I tried to know what is the actual voltage of digitalWrite(High). I don't understand why the value of analogRead does not ...
0 votes
1 answer
89 views

Why do I get different times when using analogRead() inside while loop?

I have the following code which checks the latency of another board. int triggerPin = 13; int dataPin = 9; int ejectorPin = A0; unsigned long t_start = 0; unsigned long t_end = 0; ...
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0 votes
1 answer
117 views

NodeMCU dev board shows 13 for ADC when grounded - why?

I have a NodeMCU 1.0 ESP-12E development board. Trying to hook up a LM35 to measure temperature. For that I need to use the analog pin A0. However it seems my sensor is out by about 4C. I traced ...
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1 vote
0 answers
189 views

Analog UV sensor displaying incorrect values in serial monitor (GUVA-S12SD)

Using Arduino Uno and a GUVA-S12SD sensor (https://www.adafruit.com/product/1918). Here's my circuit. 5V into sensor+, GND into sensor-, A0 to sensor out. Here's my code: void setup() { Serial....
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1 vote
2 answers
88 views

LCD TFT 2.4"" changes the values of analog read of Arduino Mega

I have a Arduino Mega with LCD TFT 2.4"" with reading 5v signal on A8 pin (Arduino mega pin) from a raspberry pi (just to test). They are grounded together. When the Arduino is without the ...
1 vote
0 answers
117 views

I'm getting really unstable analog values with my B103348 joystick

I'm trying to make my B103348 joystick control a DC motor but I'm getting very unstable values from it specifically when the y axis is at 0. This is what my Serial monitor shows... 0, 21, 21, 21, 0, ...
2 votes
1 answer
121 views

consecutive analogRead()

Has anyone noticed that if calling analogRead() in a consecutive way that the value drops by a bit as opposed to just doing a single read? And is this to be expected? I am using a Seeeduino XIAO.
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2 votes
1 answer
49 views

Arduino Multiplexer Input voltage per pin not decoupled

I am very new to electronics (software engineer background). I want to send an analog signal (5V) to one/many input wires. The input wires are connected to a 16 channel mutiplexer. My arduino then ...
3 votes
1 answer
337 views

How to reduce AnalogRead noise?

Currently trying to read off values from a photodiode through analogread. It's constantly so noisy and I thought it might be something wrong with my low-pass filter, but I decided to just connect a 1....
0 votes
1 answer
1k views

Analog read not working while using WiFi

I have an ESP32, the current program running on it uses WiFi but, if I use WiFi and Analog read at the same time, Analog read does not work. Why does this happen and what's the way around it? Hardware ...
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0 votes
3 answers
554 views

Can I test if something is connected to analog pin?

In my sketch I have a potentiometer connected to A0. The value of the pot is used to adjust the speed of a connected item. I have set the speed to have a default value, but doing analogRead() on a ...
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1 vote
0 answers
287 views

Pyfirmata util.Iterator causes serial communications issues with more than one Arduino

I'm using two Arduino Megas in a project to read data from a bunch of analog sensors and then output PWMs on digital pins according to their value. These analog signals are also being plotted on a ...
1 vote
0 answers
185 views

Problem with floating of AnalogRead

For a university Lab course i have to realize a UPS unit with a internal LiPo battery . The unit uses as battery charger a buck converter I have only a problem with the battery charger (buck converter)...
1 vote
0 answers
35 views

Math on analog read wrong result

I'm trying to execute a math of analog read but I get some weird result.. I searched about int and floats but didn't understand.. My code is : #include <SevSeg.h> SevSeg sevSeg; int bitsChange ...
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0 votes
3 answers
266 views

Inaccurate voltage readings on an esp32 as opposed to multimeter

I am working on detecting the amplitude of a signal coming from a guitar pickup. I am using an esp32 and an LM386 module for amplifying the signal. I get quite stable readings with a multimeter, but ...
0 votes
1 answer
80 views

Check pin capabilities at compile time

Are there board-independent functions to check pin capabilities at compile time? I.e. Can the pin be used as output, as in digitalWrite()? Does the pin support PWM, as in analogWrite()? Does the pin ...
0 votes
2 answers
58 views

Is defining a function improves speed rather computing average for each analog input separately

My Arduino controller reads data coming from four different sensors. After the data is read, I individually compute four input average values. I understood that I am having the same lines of code ...
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2 votes
1 answer
135 views

Why AnalogRead shows value (395) when its on HIGH State ? why not shows 1023 when its high State

I Took a output from ESP8266 and Connected it with Arduino Nano Analog input A0 i use BLYNK app to on/off D0 pin in ESP8266 , and i connected ESP8266 D0 pin with Arduino Nano A0 analogPin. when ...
1 vote
0 answers
45 views

ESP32 reading analog 2.4Ghz

Is there a possibility to analog read on the 2.4Ghz band to just read how much activity is in the presence of your device? Not parsing the messages but just listening to how strong of a signal you are ...
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-1 votes
1 answer
60 views

SEN0114 moisture sensor low max reading?

I am using the following SEN0114 moisture sensor with an ESP32: https://datasheetspdf.com/datasheet/SEN0114.html How come when submerged in water I only get a reading of ~2500? Should this not read ~...
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2 votes
1 answer
255 views

analogRead() doesn't read more than 500Hz

I connected a wave generator to the analog pins to read the frequencies of the waves generated. I used different frequencies of sine waves with a minimum of 0V and maximum of 5V. Whenever the voltage ...
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3 votes
2 answers
407 views

Arduino measuring high-voltage electric fence

I would like to know if someone has experience with measuring high voltages using an Arduino. I know you can use resistors to lower the voltage, however. I want to be able to measure the pulses of an ...
1 vote
1 answer
131 views

Time signal. Determine the presence of pulses and their duration [closed]

I want to detect the exact time signal from an FM radio station. The signal is transmitted in the form of 5 short pulses and one long one. My task is to determine the presence of a pulse in the audio ...
0 votes
1 answer
194 views

Attiny : Is it possible to analog read on PB1?

I'm trying to read an analog input on the Attiny85 physical pin 6 (PB1, PWM), but analogRead(PB1) always returns 1023. Is it even possible to use analogRead on this pin? I'm fairly new to this so ...
1 vote
0 answers
54 views

Phantom reading

my project is to control led diode and dc motor, test shield buttons, and check system run time. Testing buttons and run time i have done. Deal is with led and dc motor control. I'm getting phantom ...
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2 votes
1 answer
1k views

How to read an analog value on ESP32-CAM with the SD card reader enabled?

I use an ESP32-Cam module for a project for which I need both the SD card and the cam. According to this page, the only pins that are not in use by either the camera or the SD card reader are GPIO0, ...
1 vote
1 answer
29 views

always detects same pin as HIGH even when its not connected

Im practicing with an arduino UNO board (I'm a begginer) and I'm trying to turn some LED's on depending on which analog pin is connected to 5V. Here's my code: int statusLed = 11; int out1 = 2; int ...
0 votes
0 answers
40 views

Does anybodyknow how to program Muscle Sensors v3?

#include <Servo.h> const int x = 200 //Naming the servosServo Servo servo1; Servo servo2; Servo servo3; Servo servo4; Servo servo5; Servo servo6; void setup() { Serial.begin(9600); ...
4 votes
6 answers
2k views

What is the most efficient voltage divider for Arduino?

I need to make voltage divider, so I could read a battery voltage up to 14.4 V. Could I use very high resistance resistors for that, so the current would be very low (to not to discharge battery)? On ...
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1 vote
1 answer
57 views

Analog Read dummy file

Can we use just a analog Read without storing it i hear it it a good practice to take two reads for better accuracy example: // Read extra analog inputs for (int i = 0; i < 8; i++) { // ...
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1 vote
1 answer
155 views

Noise in Analog Read Serial from an instrumentation amplifier(ina122p)

I am trying to read the values from a simple EMG circuit (with an INA122P) using the analogRead() and plotting in the plotter using an Arduino nano v3. I am powering the ina1222p from the 5v pin of ...
2 votes
0 answers
76 views

Reliably using analogRead as a compact digitalRead

My goal is to reduce pins being used for micro-controllers with limited pins, or projects requiring a few different digital input values. How I intend to do so is by using ADC pins to gather four ...
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2 votes
1 answer
197 views

The analog read is not giving the correct waveform as that of an oscilloscope

I have code that fetches analog input values from terminals A0, A1 and A2 of an Arduino Mega 2560. When I plot the data, it does not give the desired waveform. The desired waveform is also measured ...
1 vote
0 answers
39 views

Connect k-type termocouple using o-amp

first of all I have to say that this is my first Arduino thing. I'm trying to connect a k-type termocouple to my Arduino using an LM2904 Oamp, Yes I know that this is not the best solution but is the ...
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2 votes
2 answers
177 views

printing the analogRead() functions result crashes Arduino

I have created a curcuit which reads the analog pin 3 auf the arduino nano and does other things dependant on the returned value. However I have problems regarding the analogRead() function. Whenever ...
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1 vote
1 answer
222 views

Extremely unstable analogRead() on Arduino Nano when powered from an external source

I'm doing a really simple project with an Arduino Nano and found a problem. The circuit is a simple temperature sensor and a tension read from an analog pin everything showed on a Nokia 5110 LCD. When ...
1 vote
1 answer
384 views

Nano: All digital pins do not output anything

New user here. Using the examples provided on the Arduino IDE software I could produce melodies with a piezo buzzer, or have a blinking LED. Not anymore. No digital pin is giving anything. I can see ...
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0 votes
1 answer
156 views

How does supply voltage affect `analogRead()` on AVR-based microcontrollers?

I'm using an ATmega328P based Arduino to prototype reading a TMP36 temperature sensor. I will eventually move this to an ATtiny85 based board with a battery supply. Both the TMP36 and ATtiny85 have a ...
0 votes
0 answers
301 views

eps32 bad adc even with external adc (ADS1115)

Im trying to read an analog value with my esp32 and send it over wifi to another esp32. The wifi part works flawless, however when i try to read an analog value form the esp32 its not useable. It ...
1 vote
1 answer
147 views

ADC value changing after changing Timer1 value in program

I'm writing a code where analogRead() reads ADC value from load. After reading ADC value, if it is not in range, I need to manipulate Timer1 value. Which is also getting changed. But, after changing ...

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