Hi guys,
I have relay issue even though I have used a pull-down/pull-up resistor.
How to make LED completely turn off using relay? Please help.
It is unusual to use simultaneously a pull up and pull down resistor.
Is the arduino pin, to which you have connected the relay module, declared as an OUTPUT pin ?
If that does not help, post:
Schematic?
Code?
Detailed explanation of what you are trying to do?
Those would go a long way in getting some good help.
Ron
6v6gt:
It is unusual to use simultaneously a pull up and pull down resistor.
Is the arduino pin, to which you have connected the relay module, declared as an OUTPUT pin ?
If that does not help, post:
- A schematic.
Ron_Blain:
Schematic?Ron
Surest way to send a noob fleeing in panic. 
JCA34F:
Surest way to send a noob fleeing in panic.
Yes and I am sorry about that but for the beginner learning in the deep end of the pool is not a good idea. The moderation here has been kind enough to provide countless threads on how to get help which it would appear 90% of those with questions neglect to read. This thread is a prime example. I have no clue what the thread starter wants?
Hi guys,
I have relay issue even though I have used a pull-down/pull-up resistor.
- used 10K pull-down resistor
- used 1K pull-up resistor
Both pull-down/pull-up resistor give me the same results = LED is not completely turn off although relay already off (HIGH). LED is not turn off but looked dim.How to make LED completely turn off using relay? Please help.
What do you read into that?
Ron
Well, not knowing how and what those resistors are connected to, it's impossible to say, that's why we need a detailed description or drawing, neither of which the OP is willing (or able) to post.
@wieb, please post a simple pencil and paper drawing showing how your relay is connected to other components.
And WHICH Arduino you are using.
I am very sorry about lack of details on my question.
Here is the schematic:
Both schematics doesn't work. Both unable to completely turn off the led strip.
Although relay is in HIGH state (which the led strip should be completely off), the led strip still on. It is not shining brightly (like when relay is in LOW state), but only dim.
How to to completely turn off the led strip?
Those are not schematics but anyway. With your relay board and only the relay board power it with % VDC and Ground connected. Now apply 5 volts to the Signal pin, now Ground the Signal pin. That should energize and deenergize the relay turning your LED strip On ? Off. Does that much work.
Eventually you will need to post your code also. A "shotgun" technique with Pull Up and Pull Down is not the way to learn.
Ron
What is the specification of the relay board input? Please supply a link to the details of the board. Note that the D1 Mini logic outputs are only 3.3V levels.
Here is my code:
int PIR = 16;
int LED_RELAY = 14;
bool Movement = false;
void setup() {
Serial.begin(115200);
pinMode(PIR, INPUT);
pinMode(LED_RELAY, OUTPUT);
digitalWrite(LED_RELAY, HIGH);
}
void loop() {
Movement = digitalRead(PIR);
if(Movement == true )
{
digitalWrite(LED_RELAY, LOW);
Serial.println("Movement detected, LED ON");
delay(1*60*1000); //1 minute
} else {
digitalWrite(LED_RELAY, HIGH);
Serial.println("LED OFF");
}
johndg:
What is the specification of the relay board input? Please supply a link to the details of the board. Note that the D1 Mini logic outputs are only 3.3V levels.
I am just a newbie on electronic and arduino.
And I just remembered that D1 Mini logic output are only 3.3V. But I am using 5V Relay Board. Maybe this is the source of my issue.
Because D1 Mini logic output only 3.3V, when it send HIGH to relay, it is not high enough to drive 5V relay. But how to make D1 Mini logic output to be 5V?
johndg:
What is the specification of the relay board input? Please supply a link to the details of the board. Note that the D1 Mini logic outputs are only 3.3V levels.
I repeat, what is the specification of the relay board input? Please supply a link to the details of the board.
johndg:
I repeat, what is the specification of the relay board input? Please supply a link to the details of the board.
I am using this relay board: 2-Channel 5V Relay Module | SainSmart – SainSmart.com
If you have a DMM (Digital MultiMeter), it would be a simple matter of measuring the voltage across the relay contacts. If the contacts are closed, then the potential difference would be 0V. Alternately, you can unplug the ac
led strip and measure the resistance across the relay contacts to verify open or closed when it should off or on.
Don't try to measure resistance with the led strip plugged in to the AC outlet !
As a sanity check, I would also measure the dc voltage on the relay input signal pin.
@OP,
Can you post a vendor link for the led string ?
wieb:
I am using this relay board: 2-Channel 5V Relay Module | SainSmart – SainSmart.com
Unfortunately, the documentation from Sainsmart is one of the saddest apologies for a documentation set I've ever met. The signal input current is not specified, and the schematic is little help, as none of the component values nor device type numbers is given.
Blurb claims it can be driven by TTL (IOL = 16mA). Arduino, well, it's a bit doubtful with a 3.3V supply (IOL = 5mA). Blurb also says " It can be controlled directly by ... Arduino", but doesn't say 5V or 3.3V supply.
As @raschemmel suggested, just check with a meter (or a battery and test lamp) whether the relay contacts are closing (and opening, for that matter!).
Also, if you have a DMM, measure the voltage at the board input pin when the Arduino output is LOW. It should be close to 0.5V. If it's much higher you risk damaging the Arduino.
3.3V is NOT enough to fully illuminate the opto coupler LED.
So where does that leave the contacts ?
Is the coil only partially engaged ?
That doesn't make sense because if the contacts are not touching there is no current through them. If they are close enough to arc then they could pass a reduced current. So are you implying that is the case ?
Where is the LED strip power coming from? Maybe the relay is buzzing and putting intermittent power on the LEDs, who knows.
"Maybe the relay is buzzing and putting intermittent power on the LEDs, "
I would hope the OP would not withhold that Intel.
