Questions tagged [voltage-divider]

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-2 votes
1 answer
50 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
37 views

Potentiometer problem

Firstly I tried hook the potentiometer to the bread board to see how it works and it did work. Then I wanted to hook it up to LED to see the voltage increase and decrease.. but from then potentiometer ...
-2 votes
1 answer
41 views

SIM800l not turning on [closed]

Just need a little help... I'm trying to turn on the SIM800l, but the device is not working. I'm using a 5V power with a voltage divider (10K - 47K) to the device requirement of 4V Vcc, but the LED ...
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1 vote
2 answers
74 views

Arduino Nano: HUGE voltage drop on VIN

I am building a small automated indoor greenhouse. I want to use an Arduino Nano to control some LEDs und a fan (both through relays) and a water Grove Water Atomization module. Everything works fine, ...
0 votes
1 answer
192 views

What resistor should I use when using a photo-resistor?

So I'm trying to use a photo-resistor and I learned that you should have a "fixed" resistor in the circuit. So my question is, what resistor should I have be the fixed resistor? My photo-...
1 vote
1 answer
426 views

Battery voltage measurement with voltage divider

I am using the following circuit to measure the Li-ion 3.7V battery capacity. Figure 1 – Schematic for 3.7 V batteries. This setup works fine for the 3.7V batteries. To be able to measure 9V ...
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1 vote
1 answer
454 views

esp8266 analogRead of 5.5V soil moisture sensor input using voltage divider

On an ESP8266 I try to analogRead(A0) my soil moisture sensor using a voltage divider but I get unexpected low values. The MT3608 increases the esp's output voltage from 3.3V to 5.5V which is the ...
  • 113
0 votes
2 answers
385 views

Serial Communication between ESP8266 and Arduino ( Sofware and Hardware )

I wish to connect an Arduino ( any of 328P family ) which its 5v, with ESP8266 (ESP-01, or even NodeMCU or Wemos D1 mini ) which is 3v3 logic. My goal is that ESP8266 will be in-charge of MQTT ...
  • 886
1 vote
1 answer
1k views

HC-05 Module not receiving commands and not pairing

I'm working on a project where I'll need to establish a connection between two HC-05 modules, each connected to an Arduino, but for now I'm just trying to get one to work and connect to my phone, but ...
1 vote
1 answer
77 views

How can I measure maximum range of my ohm meter?

Hello everyone I am working on a project that will measure ohm value of a resistor . Schematic / article link https://create.arduino.cc/projecthub/iasonas-christoulakis/how-to-make-an-arduino-ohm-...
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
178 views

esp32 voltage divider readings off

Trying to read from a voltage divider circuit using two 240 Ohm resistors. Getting a reading of 6.0, when it should be 1.65. Circuit is powered by a bench 3.3V and both the Huzzah32 and circuit are ...
2 votes
1 answer
752 views

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 -...
8 votes
3 answers
349 views

Measuring li-ion that arduino is running from

I am using a 5v Arduino pro mini (with regulator and power led removed). I have been reading how to accurately measure Li-ion batteries when powering from the same battery you are trying to measure ...
-1 votes
1 answer
94 views

Dynamically control the output voltage of a 60V DC input

I am hoping to control a 60V DC input source dynamically using my Arduino so that the output voltage could vary between 0v to 60v. At first i was looking into digital potential meter, however I couldn'...
-2 votes
1 answer
827 views

Voltage at AREF pin

I find difficulties to measure correctly the voltage at the AREF pin. I would measure voltages ‭with a resolution not exceeding 1 mV . nda voltage divider In one of my trials, I was using a 9V ...
2 votes
1 answer
72 views

Thermocouple and multimeter

I've put together this script that should allow my Arduino Mega to be show thermocouple readings on the serial monitor, whilst also showing readings of voltage and ohms across a given component. I'd ...
  • 51
0 votes
3 answers
4k views

Voltage divider and NodeMCU inputs

Some sensors give as output a voltage between 0 and 5V. The analog inputs of the NodeMCU require voltages between 0 and 3.3V. I plan to make a voltage divider with two resistors like in this link for ...
3 votes
1 answer
448 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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1 vote
1 answer
5k views

How to read voltage using ADS1115

I'm very new to this. I found this tutorial. But it don't explain how to read voltages higher than Arduino 5V. I have connected a 100K ohm resistor to positive and 10K ohm to negative of my 24V power ...
1 vote
2 answers
2k views

Arduino 10bit ADC is not accurate?

I'm reading the voltage with voltage divider: simulate this circuit – Schematic created using CircuitLab | Arduino is connected to both USB and a 9V adapter. float r1 = 100000; float r2 = ...
0 votes
2 answers
163 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, ...
7 votes
2 answers
1k views

How to read high voltage (40-65v) from a Solar Battery bank

I would like to monitor the battery voltage of a 48v solar battery system. The expected voltage range is 40-65v. I have tried creating a voltage divider with 2 resistors but with all values I have ...
  • 73
0 votes
2 answers
2k views

Value read is not changing while rotating pot in arduino?

I am trying to read voltage using analogRead in Arduino Uno from a voltage divider circuit consisting of 1k resistor and 10k pot. The Pot used is bourns 3296. The values obtained only range from 1011 ...
  • 1
0 votes
2 answers
415 views

Would a 100KΩ resistor connected to ground pull an open analog line down to 0

I have a project that has a photoresistor wired into a voltage divider and connected through a 3.5mm “stereo mini plug”. When nothing is in the mini plug, the analog line is an open circuit, and ...
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