what I want to do is have a output go high or low when 2 inputs are both high or low att the same time
in my head the logic thing would be some sort of a AND command but I cant find anything on the net mainly because I dont know what to look for !
I am using 2 hall effect sensors
one connected to pin 2 and one to pin 4
I have a led on 13 and 12 that lights up when the input for that output is activated
the thing is that I want port 8 that is my relay to go high when both 2 and 4 are activated just like a AND gate
I could use a 74hct08 and make a circuit but i want to code it and use the uno
I know the code is garbage but if i could please get a hint to correct it i vould be soo happy
here is my code
int hl1Pin = 4;
int hl2Pin = 2;
int led1Pin = 13;
int led2Pin = 12;
int relay1Pin = 8;
int hl1State = 0;
int hl2State = 0;
void setup() {
// put your setup code here, to run once:
pinMode(hl1Pin, INPUT);
pinMode(hl2Pin, INPUT);
pinMode(led1Pin, OUTPUT);
pinMode(led2Pin, OUTPUT);
pinMode(relay1Pin, OUTPUT);
}
void loop()
{
hl1State = digitalRead (hl1Pin);
if (hl1State == LOW){
digitalWrite (led1Pin, HIGH);
}
else {
digitalWrite (led1Pin, LOW);
}
hl2State = digitalRead (hl2Pin);
if (hl2State == LOW){
digitalWrite (led2Pin, HIGH);
}
else {
digitalWrite (led2Pin, LOW);
}
hl1State = digitalRead (hl1Pin);
hl2State = digitalRead (hl2Pin);
if (hl1State == LOW)AND(hl2State == LOW){
digitalWrite (relay1Pin, LOW);
}
else {
digitalWrite (relay1Pin, HIGH);
}
}
"in my head the logic thing would be some sort of a AND command but I cant find anything on the net mainly because I dont know what to look for !"
try the tab at the top of the forum
learning-reference
that will show you most of the basic commands
&& = and
p.s when posting please use ctrl+t then copy and paste between code tags its makes it easy for other people to copy the code for assistance and it makes reading it easier
if (hl1State == hl2State) {//are both the same..
//they are both the same
if (hl1State == LOW) {
//is one low..to get to this point they are both the same
//so test either one
digitalWrite (relay1Pin, LOW);
}
else {//not low so must both be high
digitalWrite (relay1Pin, HIGH);
}
}//they are not the same... exit if
//notice how the code is stagered
It seems apparent that you want some logic function simulated. But it is not clear which. Google logic functions, and, or, xor, and let us know which one will work for you.
jack from what im reading he wants to know when both are high do one thing or when both are low do something different
maybe im reading the original post wrong.
"from what im reading he wants to know when both are high do one thing or when both are low do something different"
Well, that would still leave a third option. What if one is high, and the other is low ? What to do then?
Digital logic circuits (and, or, xor, inverter), generally only have a choice of two outputs, either high, or low, (no third option).
BlueScreenTT:
what I want to do is have a output go high or low when 2 inputs are both high or low att the same time
Huh?
Oh - I think he means that if the inputs are not the same, then the output should be left as it is.
Another way to do this kind of thing is by bit-fiddling and using a switch statement. Not really worth it when you have just the two booleans, but for more complicated cases, it can be. The advantage of a switch() statement is that it usually compiled down to a computed goto in machine code, and so can be faster and more compact than a series of nested ifs.
switch( input1 | (input2<<1)) {
case 0: // both inputs low
break;
case 3: // bot inputs high
break;
}
Now, let's say you only wanted to do whatever it is if the output doesn't match the inputs. Easy:
switch( input1 | (input2<<1) | (currentOutput<<2)) {
case 4: // both inputs low, output high
break;
case 3: // bot inputs high, output low
break;
}
You can make the truth table as complex as you like, at the price of possibly obscuring the logic.
what i wanted was to know how to do a "AND" code i couldent find it any where as i wrote i didnt know how to formulate my search!
yes i wanted to do a logic function it dont have to be low it could also be high that all depends how i want to use it !
i could use a NC relay together with the and function to get the door hold magnet to release when i want to enter
but i got a lot of ideas and code exampels on how to get on with my project now
Thank you so much for your help
