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).
294 questions
3 votes
1 answer
194 views
Arduino R3 Uno Clone - When barrel plug connected there is 5V on USB. Why?
I have been using Arudino Megas for some projects and never had this problem. Simply enough - I am powering arduino with 12V in via barrel and take power out via VIN to 12V low very low current small ...
- 31
2 votes
1 answer
222 views
Communication between 3.3 V and 5 V system
I am using an ESP8266-01S that only works with 3.3 V power. I want to control a 5 V relay. I gave each component its own power source and got an NPN transistor and wired it like in the diagram, but ...
- 21
0 votes
1 answer
66 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
0 votes
0 answers
433 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....
0 votes
2 answers
1k 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 ...
- 61
3 votes
2 answers
402 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
181 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 ...
- 119
0 votes
2 answers
138 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 ...
- 7
1 vote
1 answer
98 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() // ...
- 11
1 vote
1 answer
359 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 ...
- 19
0 votes
0 answers
73 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 ...
- 39
-2 votes
1 answer
326 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
1 answer
281 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
609 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
187 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 ...
- 9