Questions tagged [resistor]
Passive electronic component which reduces current flow in a circuit, dissipating power as heat.
110 questions
1 vote
1 answer
275 views
LCD display connection without a resistor
Can run a LCD without a potentiometer or a resistor? I don't have any. Here it said to connect both:
1 vote
0 answers
649 views
How to use a DF Mini Player Busy Pin to start an LED Sequence?
I'm using a DF Mini Player with my Arduino Uno project I keep getting stuck on the same point - how to trigger my LED sequence. I discovered, through some google searching, that utilizing the BUSY ...
- 11
2 votes
2 answers
1k views
Push button issues
I have been using https://wokwi.com/ to learn Arduino and I am having a problem that seems to be happening no matter what I do. I am trying to set up a push button and an LED. The end goal here is to ...
- 21
1 vote
0 answers
2k views
Powering up a 16x2 LCD display with only a 9V battery
I'm using an Arduino (Nano 33 IoT) board for a project and apparently this board can only supply with 3.3 volts when a 9V battery is connected to it through Vin and GND pins. In other words, I'm ...
0 votes
1 answer
214 views
Arduino Mega, 6 push buttons for each analog input (A0-A9) - closing one results in reading by other
On day to day basis I'm more of a high level programmer, with little electronics knowledge, apologies in advance if I lack some nomenclature or basics. I communicate with my Arduino Mega via firmata, ...
- 103
1 vote
0 answers
140 views
LED brightness variations
I'm using two different types of code and noticing that in the first set up the last LED is dimmer than the rest. Then in the second set up, the first LED is brighter than the rest. I would like to ...
- 19
1 vote
2 answers
407 views
Why analogRead's value decreases when I decrease the value of resistor?(I use digitalWrite(high) to positive terminal of resistor)
Basically, my circuit contains only 1 resistor(like the basic LED circuit). I tried to know what is the actual voltage of digitalWrite(High). I don't understand why the value of analogRead does not ...
- 13
6 votes
2 answers
289 views
Do you actually NEED external resistors for switch connecting IO pin to ground?
Years ago, I encountered a fairly long debate at AVRfreaks.net about whether or not it's OK to directly connect AVR pins that are configured as inputs with internal pullup enabled directly to ground ...
- 561
0 votes
1 answer
3k 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
2 answers
770 views
How to hook up a HC-06 to Arduino Nano
So I have an arduino nano hooked up to hc-06 however every diagram of the hookup wires shows some kind of resistors (1K and 2K, rather high resistances to ignore), and I completely overlooked them. I ...
-2 votes
1 answer
875 views
Do I use an LED or a pullup resistor for stopping "floating" or "ghosting" for a matrix keypad?
I know this sounds simple, but I have an Arduino Mega 2560 and I am making a matrix keypad for a claw machine. It's a 3*4 matrix keypad. Let's just say, I am making this keypad for the claw machine to ...
- 116
1 vote
1 answer
172 views
LEDs not lighting up even though current is flowing through them, problem with ground?
I'm using a 74HC595N shift register to light up 8 LEDs but for some reason they won't turn on even though current is flowing through all of them. I provided an image of my circuit below, there is a ...
user77534
1 vote
1 answer
449 views
Arduino H-bridge for rc car
I've got an old rc car laying around, of which i would like to swap the insides, but re-use some of the parts that are already in there. The car runs 2 dc motors: one for steering, one for throttle. ...
4 votes
4 answers
3k views
Why am I receiving random input values in my Arduino?
I want to use a switch for my Arduino using digitalRead(), but I keep receiving random inputs. Whenever I connect energy to that pin, it always returns HIGH, but otherwise it goes completely random. I ...
- 57
0 votes
2 answers
99 views
Why does a pull down resistor configuration not destroy the pin it's connected to?
I don't understand why a pull-down resistor connected to ground would prevent a pin connected to 5V through a button would not destroy the pin as the current does not need to go through the resistor ...
- 1