Questions tagged [analogread]

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

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43 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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1answer
30 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 ...
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77 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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143 views

Cannot get esp8266 - 12 wifi module to always read analogRead incoming voltage accurately

So I have and arduino uno that is firing an output on pin 8. This code is not in this file just to be clear. From there Im taking that output and using it to fire pin 0 on the wifi module. Im using ...
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2answers
261 views

Binary to decimal using bitwise operators

I am trying to convert some binary data to decimal numbers. I succeeded to convert binary to hex, but now I want to do the same with binary to decimal. I want to use bitwise operators and NO array. ...
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1answer
37 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 ...
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2answers
55 views

Why am I getting erratic Analog.read() readings?

Im trying to make an arduino controlled PWM fan using a potentiometer. Ive connected the circuit as in the diagram below (The transistor is a TIP120 if it's hard to read): Here is my code: int fan = ...
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1answer
151 views

Not getting any output from ECG sensor AD8232

I am trying for the beginning to run a simple Arduino code in order to test the functionality of the ECG sensor. What I am getting on the output are some random values around 600 or around 200. I ...
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1answer
360 views

Analog output gives a close range of values

I try to get a good range of values from VMA309 sound sensor. However, when I connect it properly it gives me a range of values +/-5 like below. The documentation says it should give numbers ...
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1answer
57 views

Playing Audio from SD - Get VU, or audio waveform

I am using the library SimpleSDAudio to play a song from my SD card to an op-amp later in the circuit. I would like to take a sample from the audio pin (possibly with a Analog read) to power some ...
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49 views

how to write freerun analog samples to a file on MacOS

I've only just managed to get the Arduino IDE on MacOS set up with my ESP8266 board. My loop is running and I can see the lovely serial output in the Serial Monitor window in the Arduino IDE. I'm ...
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2answers
152 views

Arduino analogRead fluctuates from sensor unless USB connected

I have an Arduino connected to a 4-20 mA sensor through a current to voltage converter. When connected to the power supply the sensor reading fluctuates, as soon as I also connect it to a USB port it ...
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1answer
47 views

Why does the LEDs affect Analog Input?

So I'm working for a project to control RGB Led Strip using microphone or sound sensor with Arduino Nano. I'm using 5050 RGB Led Strip around 120 LEDs, and I control them using simple transistor ...
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2answers
2k views

Arduino nano getting powered through analog input?

I noticed something today. I am powering the Arduino Nano from a battery and a 5v step up converter. That works just fine and I'm getting a stable 5v output. I have a second cable coming out from the ...
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34 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 ...
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1answer
70 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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2answers
344 views

Regarding PGA bypass in ADS1262

I want to bypass the PGA to change the input signal range from +/-2.5 to 0/5 V range. I have taken the reference of example given in this library. I have interfaced protocentral-ads1262-32-bit-...
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2answers
40 views

Using SDA and SCL with analog inputs at the same time

I'm trying to build a robot arm based on Arduino UNO and PCA9685 controlled by few potentiometers. The easiest way that I figure out and find on internet is using two Arduino's, one as master and ...
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1answer
22 views

Data type explanation regarding analogRead of a photoresistor

This is a fundamental question - very new (1st post) and trying to learn. I have a photocell connected in series with a 10kOhm resistor between 5v & Gnd (to make a voltage divider) and the ...
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1answer
74 views

Using case statement with IR emitter reciever

I am trying to use two "infrared obstacle avoidance modules" to work with the following sketch. From all my research, I believe, a case statement is my best option because, (I understand) the sketch ...
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16 views

How to calibrate Arduino DUE analog readings?

I am having a problem with the analog readings on my Due. On pin A4 and A5 I am measuring voltages: double vcc = 3.288 // taken on pin 75 (ADVREF) ; analogReadResolution(12); result = analogRead(A4) ...
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35 views

Why does setting a digital pin to INPUT make one of my analogue pins into a digital input

I have connected four sensors to four of the analogue inputs and I can read the values they return just fine, it all works. However, I also need a digital input and when I set the mode of one of the ...
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1answer
270 views

DHT11 analog or digital?

I saw some projects with DHT11, some connect it with analog pin, others connect with digital pin. Is there any difference / advantage connecting to the analog?
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2answers
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Substitute multiple potentiometers for push buttons and single potentiometers

this is my first post here. For some time I have been struggling with a problem and would like to know if anyone has a solution to share. I am building a 4 tone sequencer, where I use 4 ...
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1answer
43 views

Is it possible to measure analog output?

I'm using PWM to control LED brightness using MOSFET, using analogWrite(pwmPin,val), while val is a 12 bit bit value. pwmPin is defined as- pinMode(pwmPin, OUTPUT); Since val changes in time due to ...
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1answer
50 views

How to Read ADC value without Common GND ? (Possible or not !)

I want to Read external signal with the microcontroller. But the problem is that ADC does not work because the signal GND and the microcontroller are not Common, My question is, have you ...
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477 views

Using ESP32 to measure vbat

I'm using ESP32 to read an analog value of a liPo battery (3.7v-4.2v). Since ESP32 DAC's is 3.3v I'm using a voltage divider ( 2x10K resistors ), to split bat's voltage into ESP's GPIO36. So far ...
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3answers
132 views

What is the correct way to interpret the built-in Analog-to-Digital Converter output?

When using the built-in analog to digital converter of the Arduino Uno Rev 3's Atmega328P with a reference voltage of 5V, what is the appropriate function to interpret the output? There is conflicting ...
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1answer
203 views

Why does the reading on the ESP32 read max, when the reading on UNO read accurately?

I have a 'Capacitive Soil Moisture Sensor' hooked up to my Uno. Very simple code. AnalogRead(MoistureSensorPin); This will return a differing value that I can work with. When applying the same code ...
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1answer
62 views

When does the ADC take the reading?

I'm experimenting with the "2 pin capacitance meter" and trying to make it more accurate. Currently I've made the Arduino read 62.5 ns intervals but this means the time for the ADC to read is taking ...
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0answers
37 views

Problem with Reading Multiple Analog Values From ESP8266 NodeMCU

I am using ESP8266 nodemcu with ADS1115, but values are totally wrong. Why this happened? Is there any solution to extends the Node MCU 8266 pins with accurate sensor values ?
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Fluctuating readings of LM35 temperature sensor (+- 5°C) with Arduino UNO

I am trying to read a LM35 temperature sensor with Arduino UNO which I got as a gift. The issue is the fact, that my readings of sensor are, well, suspicious at least - they jump with each reading ...
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68 views

Need help in the problem with analog input readings and RTC DS3231

I have 3 analog input(0-1024). I want two outputs based on levels of analog inputs. Eg. inputs have 2 levels. for A0 at 300,digital output pin3 turns ON; and A0 at 500, digital output pin 4 turns ON. ...
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1answer
237 views

Why does analog sensor “hum” when plugged into common ground?

I have the ground for an SD card module, LED, and piezo sensor all plugged into the same ground rail. When doing this I get a low "hum" in the piezo readings where instead of reading ground voltage (0)...
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1answer
110 views

ADC register always returning high

Regardless of whatever voltage at A0, the software is always returning high (1023) volatile unsigned char* ADmux = (unsigned char*) 0x7C; volatile unsigned char* ADCSRa = (unsigned char*) 0x7A; ...
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1answer
162 views

Measuring 12 V via voltage divider: choosing the right resistors

I want to measure a 9 V battery via one of the analog input ports of my Arduino Nano. From all the schemes of this great answer, I choose the simplest one, the voltage divider. Assuming the maximum ...
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1answer
55 views

Variable sets to 32767 - MATLAB Arduino

I am running out of ideas of what may be causing this problem, and I would appreciate some help identifying anything I am overlooking. Quick Problem Summary A variable gets set to 32767 quite often ...
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2answers
224 views

Noise on piezo analog read due to Arduino power supply

I am making a device that measures temperature and vibrations and records the values onto an SD card. It will be a standalone device. The hardware used: - Arduino Uno - PCF8523 RTC clock - MAX3186 + ...
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1answer
222 views

Specific ports on Teensy 3.6 not reading correct bit resolution using ADC library?

I have a basic circuit, where I'm reading analog values from 14 infrared receivers. I set the bit resolution to 16 but specific ports are returning 10 bit values (from 0 - 1024) instead of 16 bit ...
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2answers
423 views

ignoring potentiometer value variations

I've got a 50k potentiometer connected to an Arduino Uno. The user should adjust the hue of an Adafruit NeoPixelStrip. I've got the following code inside the loop function: int hue = analogRead(...
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1answer
38 views

Sound sensor's output stucks to high values when I include a delay in the loop function

I use Waveshare's Sound Sensor module. I use this simple code to test the module: As you can see, the problem is that when I have a delay in the program, once the analogRead is bigger than 10 (by ...
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1answer
81 views

Mapping values from analog input giving unexpected values?

Mega 2560 I am reading in values from 3 pots then mapping them to values between 0 - 255 #define REDPIN 7 #define GREENPIN 8 #define BLUEPIN 9 int red_pot = A0; // analog pin used to connect ...
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79 views

Temperature varations using ADS1115 and voltage divider to read 12v

I have an issue with reading battery voltages of three 12 volt batteries using an ESP-01 and an ADS1115. I have been graphing the measurements and the all of the graphs have a temperature component ...
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1answer
514 views

Noisy analogRead

I'm trying to read voltage using Arduino, here's the code: float r1 = 99700; float r2 = 10004; float adc, voltage; unsigned long analog; void setup() { Serial.begin(9600); analogReference(...
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0answers
34 views

Strange cyclic errors in analogRead on Nano

I am trying to build an emergency shutdown of a gas valve based on the output of a smoke detector. It basically measures the voltage on the buzzer of the smoke detector, and if high enough, changes ...
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1answer
3k views

Read frequency of input in digital pins

This is a somewhat theoretical question: Let's say I have some sensor that sends digital signals to one of Arduino's digital ports. Now, I don't know the frequency it sends those signals in. For ...
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0answers
409 views

Measuring Amplitude/Frequency of sound

I need to read an analog signal at about 500-1000Hz for at least 5 seconds. I've a battery powered microphone wired into an analog and ground pin on my arduino and am trying to measure the frequency ...
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2answers
92 views

Buzzer interfere with thermistor reading

This is how i wired the thermistor and buzzer: simulate this circuit – Schematic created using CircuitLab And the code: #define RT0 10000 #define B 3977 #define R 10000 float RT, VR, ln, TX, ...
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2answers
3k views

Safely enabling voltage divider on a 12V battery

I'm planning to monitor voltage of a 12V battery with an Arduino's ADC pin connected via a voltage divider. Since I don't want the circuit itself to drain the battery when not in use, I want to use a ...
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117 views

ESP32 PH probe analogRead Value Alternating

i got an ESP32 WROOM32-OLED with a PH-Probe hooked up to it (PIN39). When i short the probe interfcace to get a PH07 reading (connecting the middle of the probe interface to ground) i get really ...

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