Excellent video. If only all the professors of whose lectures I’ve sat in could explain things so clearly. I swear that they always think it’s their students fault for being incapable of comprehending it, when in reality they overcomplicate and thereby mystify what are in reality basic concepts which anyone can understand-so long as someone like you explains it.
You have NO IDEA just how much you helped me see the difference. I have a Rasp Pi 4, for about a year and a half now, and awesome fun they are. I have to learn so much more. I watch you guys all the time to help me learn electronics in a later life. I'm in my late fifties and I'm learning this on my own, with help from you guys and internet sources always helped. Superb Thank you....👌👍
Boom! just like that, my switch actually controls my relay! I'm a 4th year Mech Engg student making a conveyor sorting system for school, and I could not for the life of me figure out why in the off position my relays would go nuts. Thank you, Mario. You saved me from a lot of frustration!
I've been working on making a buzzer controlled by a PWM signal for close to a week now. I've been troubleshooting my code since the beginning thinking the mistake was in there. After this video I solved my problem in less that 5 minutes. Great video!
Thank you so much mate. I'm doing a quiet big project for swimming pools, to control the filter pump, booster pump, chlorinator, heater, valve actuators, variable speed pumps etc, my project was working fine on protoboard, I printed the PCB and the button interferences show up on butons inside the MENU screen, now I'm using pullup method using the ESP32 internal resistors, and voilà it's working fine again. Many thanks for your time to make and post this video, I'm really gratefull. Cheers.
As newbie i can say , i've got same mistake(i realized that after whole day of thinking). Im really glad , that im not the only one who did that mistake😅
Wow! Best explanation yet! Perfect mix of theory and circuitry and how they work! Thanks. Still one puzzle. The original problem was due to noise voltage in the open or loose wire going to A0. In your diagram for pull down, that same wire is still there with the OPEN switch. Why isn't that same noise still present? Indeed it is now connected to ground via a resistor making the current flow for this very tiny voltage difficult. So why doesn't the original noise voltage still flow to A0?
Not being very electronic profficient I also had a problem to get my head around it. But in summary. Voltage doesn't from current does. If flows from positive voltage to ground. And through pulldown resistor and the use of voltage divider we set ground at the pin. Arduino detects the voltage value not the flowing current.
Thanks Mario. Excellent explanation. For this button/LED set up, is it necessary to use and Analog pin, or will the set up also work with a digital pin? Thanks
Something about 6:45 to 7:30 I just am not understanding. Why would it read high with a big fat resistor in the circuit? …i mean I get that I need to add a pull up / pull down resistor - but I can’t follow the logic of where/how the electricity is flowing. It’s strictly a ‘me’ problem…
In pull-up configuration, why do we have all 5V when the button is not pressed ? Normally, shouldn't we have much less than that because of the big resistor of 10k ohms that will decrease those 5V ?
@@marios_ideas Actually he was not asking about the voltage divider when the circuit is closed, but why when the circuit is open the 5V goes through a 10k resistor to A0 but still remains 5V instead of decreasing for e.g. to 2V? I didn't understand this too.
A push button is a mechanical switch that consists of two states: pressed and unpressed. When unpressed, the button effectively disconnects the digital pin from ground, so the pull-up resistor is the only component in the circuit connected to the pin. Since the resistor has a high value (10k ohms), it limits the current flow to a very low level, and the voltage at the pin remains close to 5V.@@SebVEVO
Since there is no current-flow when the button is not pressed, just use U=R×I to understand. Without current there is no voltage drop after an resistor.
I guess only if you do not want to have the Pullup logic and want to stick to pulldown. For small project adding a resistor is not a big deal. but for more complex ones if you create custom PCB minimmising number of conponents is super important. A lot of people do not also realise that those pullup resistors are available:)
Why does it not blink when we haven't pushed the button one time yet ? Why does it start to blink only when we do push the button and release it for the first time ? Does it ??
instead of pinMode (9,OUTPUT) is it possible to declare SDA(A4) or SCL(A5) as output to switch on an oled to show time for 5 seconds in a night clock project and a capacitive proximity sensor instead of a button?
