I’m relatively new to programming the Arduino but I’m working on a project where I’m looking at using some switches, probably 8, and having a button that while certain switches are high and certain switches are low, when the button is pressed a servo is triggered but only after the switches are returned to low. Is this possible and which statements should I use?
Hello mpboyer3496,
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Start with an Arduino UNO. For each switch or button, pick an I/O pin. Pins 0 and 1 are special (Serial port) so best to start with 2. Set the pin to be an input with the internal pull-up resistor enabled:
// Give each pin number a name so the sketch is easier to understand
const byte ButtonPin = 2;
void setup()
{
pinMode(ButtonPin, INPUT_PULLUP);
pinMode(LED_BUILTIN, OUTPUT); // The LED marked 'L' on the UNO
digitalWrite(LED_BUILTIN, LOW); // Turn the LED off
}
Now the pin will read as HIGH unless you connect it to Ground. Put your button or switch between the pin and Ground.
Now your sketch can use digitalRead(pin) to check if the switch/button is open (HIGH) pr closed (LOW).
// Do something when the button gets pressed
void loop()
{
if (digitalRead(ButtonPin) == LOW)
digitalWrite(LED_BUILTIN, HIGH); // Turn on the LED
}
Now just expand on that. 
Also, this site has tons of tutorials, examples, and basic documentation of all common features. Look under the "documentation" tab.
The example sketches that ship with the IDE are designed to help a beginner get started.
I know my way around the Arduino to a point but what I don’t know is how to accomplish the question that I asked which I thought was pretty specific.
I'm relatively new to programming the Arduino but I'm working on a project where I'm looking at using some switches, probably 8, and having a button that while certain switches are high and certain switches are low, when the button is pressed a servo is triggered but only after the switches are returned to low. Is this possible and which statements should I use?
mpboyer3496:
I know my way around the Arduino to a point but what I don’t know is how to accomplish the question that I asked which I thought was pretty specific.
If you want help with your sketch, show us what you have so far. If you want someone else to do the programming from your specification, try the "Gigs and Collaboration" section of the forum.
I would recommend an array of pin numbers for the switches. I would also recommend a State Machine design for the various steps. For each step where you are waiting for something to happen, have a state. When that is the current state, check to see if the thing you were waiting for happened.
Short answers:
mpboyer3496:
Is this possible
Yes
mpboyer3496:
which statementsshould I use?
if
But just to clarify your ask? Seems you want to read the switches when the button is pressed, and if at that moment the switches are correctly set (say 10101010 for argument's sake), remember that fact and prime the system so to speak, so that later on when the switches are all 00000000, move the servo?
If that was a correct statement of the problem, then you have two states, say IDLE and PRIMED, start in IDLE.
In state IDLE (and remember loop() is looping away like mad) read the button. If the button is not pressed, do nothing. If it's pressed, read the switches. If the switches are wrong, do nothing. If they're correct, move to state PRIMED.
In state PRIMED, read the switches (and remember loop() is looping away like mad). If the switches are not all 0, do nothing. If they're all 0, do the thing with the servo, and (presumably) revert to state IDLE.
(You could actually get away with one [edit: forgot to say boolean] state variable, since it would have two values true and false, so could just have variable "primed". If it's false you're idling, if it's true, you're primed.)
I actually coded it with 3 states, IDLE, PRIMED and ACTIVE. You're welcome to the code if you want it.
You need to specify what happens in PRIMED if the button is pressed again. Should it ignore that press and stay PRIMED regardless of what may have happened to the switches meantime, or re-check the switches and revert to IDLE if they're wrong when that press occurs?
mpboyer3496:
I know my way around the Arduino to a point but what I don’t know is how to accomplish the question that I asked which I thought was pretty specific.
I thought your question was specific and meaningless. It was like 'I am working on a project to write a book in English with characters in the fishing community, is this possible and which words shall I use?'. The answers being 'yes' and 'ones from the English language'. This is precise and useless. The answers to your questions are 'yes' and 'any of the statements valid in C++, according to the needs of your program'
You will I hope realise my response is a standard reply I give to try to encourage better questions, it is therefore generic and not tailored to your particular question. If you have since got useful answers from other people who saw something in your question that I could not see then all well and good. If you are still in need of help then please follow the advice for asking a good question.
Good luck with your project.
To me it is more like I’m trying to write a book in a language that I barely speak and need to communicate something specific to that language but I don’t know if my English translates properly to that language.
mpboyer3496:
To me it is more like I’m trying to write a book in a language that I barely speak and need to communicate something specific to that language but I don’t know if my English translates properly to that language.
That is where the universal language of images, diagrams and code solves the problem! But where are they?...
I have a project that has two switches and several conditions that must be all be in the correct state for the next thing to happen.
I'm using a while loop with a few IF statements in it.
I was and still am a bit of a novice but read through plenty of tutorials on while and if and eventually figured it out.
I suggest just starting with one switch and get that working and then Expand on that. That's what I did and learned a lot by battling through it.
