Questions tagged [voltage-level]

Voltage level should be used for questions that are referring to using hardware together that operates on different voltages (the "concentration" of electricity).

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1 answer
322 views

ESP32 struggling to trigger relay module consistently

I'm working with a 4-channel, 5 V relay module and an ESP32 which operates on 3.3 V. The setup seemed to work well initially but I have started experiencing some inconsistencies. One of the four ...
0 votes
1 answer
40 views

Same LED but different brightness on same PIN

I connected a led to pin 7 (with a small resistance to avoid burning it) and tried the code below, with and without pinMode as output void setup() { pinMode(7, OUTPUT); Serial.begin(9600); } void ...
-1 votes
2 answers
8k 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 ...
0 votes
0 answers
204 views

Arduino Uno RFID-RC522 won't scan any card or tag

So I bought a RFID-RC522 module with a blue tag and a white card, and I searched for tutorials and found this library that I used it. and here is my code : #include <MFRC522.h> #include <SPI....
61 votes
4 answers
263k views

What are the 5V and VIN pins for?

I believe I can supply the Arduino with power in three different ways: Use USB. The design trusts the 5V to be regulated, and does not regulate it in any way. Use a regulated power source, trusted ...
1 vote
1 answer
104 views

Inconsistent results when reading input looking for spike patterns

I'm writing a library that will interface with a control unit on a refrigerator compressor pump (QDZH35G). One of the features of the control unit is that it can detect what problems it's encountering ...
-2 votes
1 answer
195 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 ...
3 votes
2 answers
181 views

How to turn LEDs based on voltage readings?

I am trying to turn LEDs in an LED bridge based on the voltage reading from a power source. when the Voltage is zero nothing is ON and then the LEDs gradually turn ON as increase the voltage connected ...
1 vote
1 answer
167 views

ARDUINO DC Motor Control over IR Sensor INPUT

I'm working on a school project where I'm building a small convyeor belt using an ARDUINO, DC motor and IR sensor for moving object detection so my color sensor can read color value. I'm using single ...
0 votes
2 answers
72 views

Pin outping 1V instead of expected 5V, not hardware related

Heyo everyone ! I'm in a project where I need to send a signal if I detect vaccuum. I'm sending the signal on PIN 9 but I soon realized that I was only getting 1V. Tought I was alternating between ...
1 vote
1 answer
54 views

Program work when used Delay() but same program doesn't work with millis()

I'm running a dc motor using esp32 and mosfet by taking readings of IR. Program works fine when used delay() but same program doesn't work when uploaded using millis(). //This uses fixed delay() // ...
0 votes
0 answers
39 views

channels on logic level shifter outputs high

so I have a logic level shifter which is TXS0108E ,I use it to shift the eps32 ouput volatge to 5v to be used with motor driver ,when I test it with multimeter , all the channels on the B side outputs ...
-3 votes
1 answer
176 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 vote
1 answer
334 views

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 ...
-1 votes
1 answer
137 views

Can the Arduino Uno use a negative supply voltage (0V & -5V)

I acquired a bread-making machine. See control board image. I want to use the machine for other purposes and control the buttons, paddle, heater & 7-segment display with an Uno. As it stands, the ...
0 votes
1 answer
248 views

How to trigger a function by detecting voltage change?

#define monitor_pin 14 void setup() { pinMode(monitor_pin , INPUT); } void loop() { unsigned long d1 = pulseIn(14, HIGH); if (d1>0){//trigger function} } I know there is a function ...
2 votes
2 answers
1k views

Connect 5V relay to ESP32 WROVER B board

I need to use a ESP32 WROVER B based MCU board with a standard (cheap) one-channel 5 V relay (e.g. to switch on a mains-power appliance). Attempted removal of excess solder around the headers ...
1 vote
2 answers
3k views

Connect Arduino Uno RX/TX to 3.3v NEO-M8N gps module

I'd like to connect an M8N gps module to an Arduino Uno. From what I understand the Arduino pins 0-RX/1-TX work on 5V the M8N RX/TX work on 3.3v the sensor-TX sending to the Arduino-RX should work (...
7 votes
1 answer
5k views

Two batteries sharing ground?

I need to power my arduino and 2 DC motors requiring 6V each, I want to power the DC motors with a 6V battery through the vM pin on an h-bridge and use a 9V battery to power the Arduino itself. On my ...
1 vote
0 answers
2k views

5V MCP2515 to 3.3V Teensy. How to reduce the MISO voltage

So to try and speed up my project, I have moved from using two UNO's to a UNO on the receive side, and teensy 3.6 on the sender side. However, no dice. The UNO doesn't receive any data or even try to ...
4 votes
1 answer
1k views

Measure lipo voltage while powering arduino

I have a arduino pro micro 5V that I want to power with a 3.7V lipo. I also have a charging module to charge the lipo. (https://www.banggood.com/nl/TP4056-1A-Lipo-Battery-Charging-Board-Charger-...
1 vote
1 answer
46 views

Will the noise from a voltage regulator interfere with IR LEDs and receivers on an Atmega328? (Arduino Uno sketch)

I have a project which uses an IR LED and receiver to communicate with other Arduinos. I am using the Atmega328 out of the Uno, rather than the whole Arduino board and I need it to be battery-powered, ...
0 votes
2 answers
2k views

Choosing Right Power Supply for Arduino - ESP8266 - HC-SR04

If I make connections like you see in picture below, will it work? Will I damage ESP or HC-SR04? As I know; HC-SR04 (VCC) -> 5V ESP8266 (VCC) -> 3.6V ESP8266 (RX/TX) -> has 5V tolerance ? I ...
1 vote
0 answers
69 views

I2C and logic shifter troubleshooting

I'm attempting to use a SparkFun bidirectional level shifter (Link here) to connect up a 3.3v wii nunchuk to a 5v Arduino Uno circuit. For now all I'm trying to do is write the position of the ...
0 votes
1 answer
1k views

M5Stack - confused about I2C bus voltage

I've recently got one of these nice M5-Though devices (basically a water-proof M5-Core2). They have these 4-wire sockets to connect their sensors. The I2C socket has 4 pins for +5V, GND, SDA and SCL. ...
2 votes
1 answer
1k views

powering arduino with a voltage divider to increase lifespan

I have a chinese arduino nano that I'm planning to use to open a door using a numeric keypad. My power source is 12V and I want it running 24/7. I have read that the first thing to fail on an arduino ...
3 votes
2 answers
636 views

5V alternative to Due?

I've designed a circuit controlled by an Arduino Mega 2560 involving a number of external components all running on and sending out 5V signals. I'm now realizing that the 8Kb of SRAM on the Mega 2560 ...
2 votes
1 answer
142 views

So many missed bytes with serial comm

I have a setup with serial comm from Raspberry Pi to Arduino. It's communicating at baud 9600 on both devices, and from Raspberry Pi 3b+ GPIO-14,UART0,TX0 to Arduino Nano RX0. There's a level shifter ...
4 votes
2 answers
800 views

How to protect my arduino, while hotplugging its power supply and other related electronics

The unsolved: when I connect power and signal lines to my Arduino - while power is on - I potentially kill it. I have fried 2 so far. Situation: I have build an DMX-controlled lighting fixture, ...
1 vote
0 answers
108 views

Using a level converter to adjust the voltage levels

we are currently working on a device that needs us to connect an sd card reader to 2 Arduino’s ( Uno and zero) , however, we just found that it is not possible to do so without a level converter , may ...
1 vote
2 answers
85 views

Level shifter with diode - not pulling to zero

I'm interfacing a 3.3 V device (a GPS module with a serial interface) to a 5 V Arduino Nano. The circuit I am using is this: simulate this circuit – Schematic created using CircuitLab I don't ...
0 votes
1 answer
103 views

Arduino 5v pin outputting lower power than expected

I have hooked the pin v5 of an Arduino Nano 33 BLE to the A0 pin and measured the value by doing Serial.println(analogRead(A0));. I would expect to see 1023 however instead I see the value oscillating ...
1 vote
0 answers
102 views

MQ-4 Sensor working fine with Beetle Bluno BLE but not with Arduino Nano 33 BLE

I have an MQ-4 sensor connected to a Beetle Bluno BLE that seems to work fine, however, when I change the board to an Arduino Nano 33 BLE, the sensor doesn't seem to work well (I get an arbitrary ...
2 votes
2 answers
2k views

Lolin NodeMCU V3 and 5V sensors

I am new to Arduino and electronics so please correct me if I made a mistake. Many sensors and actuators require 5V. The Lolin NodeMCU V3 has outputs of 3.3V. I want to have them working together. ...
1 vote
1 answer
54 views

Pulsing 3v into a capacitor to create custom Voltages

I was wondering if it is possible to create diffrent voltages by just pulsing power into a capacitor, Im using an esp32 which can only output 3v or nothing on its GPIO pins, and i need to make it ...
1 vote
1 answer
801 views

How to connect an Output to a Pullup Input of another arduino

:tldr; Could problems occur if one connects a HIGH Output of one arduino to a PULLUP_INPUT of another while using differed power sources? Hi I'm building some devices for a LARP Dungeon (think Escape ...
2 votes
1 answer
557 views

How to calculate required amperage of multiple motors?

I a very simple question about calculating the amperage I need to run 5 stepper motors from my Arduino Uno. If I have 5 28BYJ-48 stepper motors(which are 5V and are said to require about 240mA each) ...
2 votes
0 answers
712 views

Help needed with driving multiple stepper motors on arduino UNO

I am brand new to Arduino but have good experience with Raspberry Pi's and Microchips. My problem is that I am having trouble driving many stepper motors at once. I am using the AccelStepper library(...
0 votes
2 answers
944 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 ...
1 vote
1 answer
244 views

what voltage level is a digital low for the interrupt mode LOW?

I am learning about interrupts and one of the interrupt modes is LOW which triggers anytime the pin is a digital low. Can someone tell me what voltage that is for an Arduino nano? I did a google ...
4 votes
4 answers
14k views

Can I change VCC pin to 3.3V on a 5V Arduino Pro Micro?

I'm using a 5V Arduino Pro Micro (schematic). For my project, I'm using the VCC pin to output power to an external device. I need VCC to output 3.3V to the external device. Can I open jumper SJ1 to ...
22 votes
10 answers
105k views

How to identify Arduino Mini Pro 5v vs 3.3v

I have many Arduino Mini Pro, every from different seller. Few are 3.3v and most 5v. I had to clean table for Xmas and now I do not have any idea how to identify 3.3v Arduinos. They do not have any ...
21 votes
3 answers
16k views

Arduino Pro Mini (3.3V version) input voltage range / tolerance

I have a few Arduino Pro Mini clones (cheap Chinese stuff) and would like to power them with 12V power supply (same as fan voltage). According to the Arduino Pro Mini spec the RAW pin can take 3.35-...
0 votes
1 answer
994 views

Calculate battery (18650 Li-ion) voltage using ESP8266-12E

i am trying to calculate the battery voltage using ESP-12E module. I am using a voltage divider circuit to calculate the same. Here is how my circuit looks like: And here is how my code looks like: ...
0 votes
2 answers
1k views

I'm working on a NodeMCU project and have a small doubt about LEDs and resistors

In my NodeMCU I want a statement to turn on an LED, which is easy, just use pinnumber, HIGH. But, what I'm trying to do here is connect multiple LEDs to one pin like this: I just wanted to know if ...
1 vote
1 answer
179 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 ...
1 vote
1 answer
2k views

How to implement brown out detector arduino ESP32?

We are using ESP32 with arduino sdk for developing our application. In our application we need to implement BOD to detect with specific voltage level. Basically we want to set specific voltage level ...
0 votes
1 answer
2k views

How much voltage and amps for 2 SG90 servos?

Question is pretty straight forward: How much amps and voltage do I need for 2 SG90 servos? I want to use 4 but you might already know that Arduino Uno only has 2 5V ports.
1 vote
1 answer
84 views

Can I safely connect my A6 GPRS module to this 5V 2A phone adapter

I have an A6 GPRS module, and my Samsung phone power adapter has output of 5V and 2A. But it also says 9V and 1.6A My Phone's Adapter 👆 So would it damage my A6 GPRS Module if I plug this to it via ...
1 vote
1 answer
99 views

Joy-IT RS232 Shield and RS232 voltage levels

First of all, sorry if this is a dumb question, but I'm pretty new to the whole Serial RS232 concepts. I do have an Arduino Board that, from what I read about, is not able to communicate via RS232 ...

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