Questions tagged [analogreference]

23 questions
13
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4 answers

Does ADC conversion to a voltage rely on the actual value of the +5 V pin?

Questions: Does the conversion of the ADC count to voltage depend on the actual voltage of the +5 V pin? If yes, what is the accepted method of getting that voltage from the board? Background/Detail: I have a circuit in which I have an Arduino…
Caribou
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4
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3 answers

Powering the Arduino with a battery and reading the battery voltage

I am trying to display the battery voltage as it is being used to power the Arduino. I have tried powering the Arduino through the USB and the battery voltage is read accurately when compared to the multimeter reading. But when the battery is…
acho
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3
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4 answers

what is arduino adc reference?

I'm using arduino for the first time and don't really understand what am I suppose to plug to the ADC refernce PIN... or if I even have to use it while plugging analog sensor to the arduino, thanks!
Eyal Givon
2
votes
1 answer

Nature of the voltage reference instability of internal 1.1V reference of ATmega328P (Nano)

The ATmega328P data sheet in table 29-11 on page 324 notes that the internal 1.1V reference (VBG) may vary between 1.0V and 1.2V. In this answer this is called "not stable or accurate". Question: Is this "unstable" or "inaccurate" or even both if I…
Harald
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2
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1 answer

Inaccurate and non-precise voltage reading from Arduino Analog pin

float get_volt() { rawVolt = analogRead(voltageSensor); vOUT = (rawVolt * 4.6) / 1024.0; vIN = vOUT / (R2/(R1+R2)); //if(vIN>12.0){vIN=12;} //if(vIN<11.12){vIN=11.12;} //return (vIN - 10.18) * (100 - 0) / (12.0 - 10.18) + 0; return…
2
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1 answer

Vcc measurement with internal 1.1V reference fails on 3.3V powered Atmega328

I need to monitor a battery plugged to an ATmega running on standalone mode. I use the "ATmega on a breadboard (8 MHz internal clock)" bootloader. More info here When the ATmega is powered with 5V the sketch outputs good values : arround 5100…
2
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2 answers

Arduino protecting analog input with internal voltage reference

Usually a common way to protect an analog input consists on reducing voltage and current in the following way: Current limiting components, as Resistors or inductors and voltage limiting components as diodes, zener, tvs. In this case for components…
piertoni
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2 answers

Can i supply the AREF pin with an Analog pin from the same board?

I guess its a dumb question but couldnt find anything about it online. I know its possible to supply the AREF pin with 3.3 V to increase the ADC resolution. For the project i am working on the analog voltage i will be reading will be between 0 and…
1
vote
3 answers

AREF pin on Arduino Uno R3

edit So then, AREF can only output a voltage when used by the ADC, but not when used by the AC. That is what I sense all your answers are pointing at, yet none has it black on white. My questions remains unmodified, below: On the Uno R3, is the…
kellogs
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adc arduino using reference voltage to read stable/constant lithium battery voltage

I want to read my lithium battery voltage. I WANT TO CREATE A FUNCTION TO READ MY 3.7~4.2V,1200mAH BATTERY VOLTAGE THROUGH A MICROCONTROLLER (ARDUINO OR ATTINY44). THEN I WANT TO CALL THE CREATED BATTERY FUNCTION IN THE FORMULA TO READ PRECISE…
1
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1 answer

Arduino , python , pyfirmata , standard firmata

Is there a way to change arduino analog reference to EXTERNAL IN PYTHON using pyfirmata or any other library ? Necessary Links : https://www.arduino.cc/reference/en/language/functions/analog-io/analogreference/ My sensor has a 3.3 volt operating…
1
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1 answer

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 the Nano is connected to the USB everything…
1
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1 answer

How to work with analog readings using RPi and Firmata?

For context: I'm working on a project where I need to use sensors to figure out the current state of the environment. This process is done using an Arduino UNO and a RPi. The easiest way that I found to perform communication between both boards is…
1
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1 answer

Using Li-Poly battery to run UNO + Adafruit data logger

I want to power Arduino UNO+Adafruit data logger (https://www.adafruit.com/product/1141) with a 3.7V 2000mAh Li-Poly battery. I am providing an excitation voltage of 3V, through one of the digital pins and a potential divider arrangement, to a…
NRai
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1 answer

Arduino Uno, does a lower Aref voltage work well for measuring current? without increasing ADC integral non-linearity

I want to measure current using a Arduino Uno and use a very low resistance of 0.1Ohm or lower for the shunt resistor to measure the current(to reduce power waste and heat generation), as a result resolution wouldn't be good at lower currents, while…
TeD van Loon
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