I sincerely hope that I'm not going to annoy everyone with my noobie questions. I've been looking at getting into the Arduino as a hobby and I'm ready to make the plunge (I think)
I have a few questions though. I haven't purchased all of the hardware yet so if you have suggestions....
What I would like to do is build an alarm clock that will not shut off until a random 6 digit code is entered (I tend to turn alarm clocks off in my sleep) Here are the items that I am looking at
1 LCD Display (to show time etc:)
1 LED Display
1 9 digit keypad (for number entry)
1 keypad for well, setting time and stuff
Now here is where I am confused. How many shields can be used with the Arduino? I would like to add an FM receiver which I seen a shield for and would also like to add speakers, potentiometer for volume and a proximity sensor in order to hit the "snooze" button by simply waving my hand.
In addition to my "how many shields" question. Would the Arduino have enough inputs for all of the above? Also, can the Arduino run two separate displays? (The LCD and LED?)
I sincerely hope that I'm not going to annoy everyone with my noobie questions.
Of course not! "noobie" questions are the most fun to solve, because they're not as complicated as the questions us experienced people ask! ;D
How many shields can be used with the Arduino?
There's no limit, as long as together they don't draw more than ~500mA from the +5V pin, and they don't interfere with each other by using the same pins.
Would the Arduino have enough inputs for all of the above?
Impossible to say, without knowing how many pins the FM receiver shield takes up. I would say it should be possible, but you may end up using Shift Registers and/or Serial-enabled LCDs.
Do what I do, get another cheap alarm clock at walmart and put it on the other side of the room so you will have to get out of bed to shut off the alarm.
Now here is where I am confused. How many shields can be used with the Arduino?
shields are just stacking daughter boards, and the number doesn't matter, it is what pins they use, if two shields use the same pin they cannot be used at the same time.
you could just build a clock + keypad and have it turn on and off a FM radio via a relay, having the audio signals passing through the arduino is kind of wasteful anyway.
I wouldn't even bother using shields, a serial LCD just uses two pins, and using cables gives you more flexibility in design.
shields are just stacking daughter boards, and the number doesn't matter, it is what pins they use, if two shields use the same pin they cannot be used at the same time.
The number does matter; insofar as to the amount of current each shield uses...
you could just build a clock + keypad and have it turn on and off a FM radio via a relay, having the audio signals passing through the arduino is kind of wasteful anyway.
I can see where having an FM receiver chip could be useful; it would allow you to use the same interface to tune the stations, select (and save) presets (each person with an alarm can get their own station!), and you could even have the alarm slowly ramp up the volume of the station when the alarm goes off...among other fun things.
I wouldn't even bother using shields, a serial LCD just uses two pins, and using cables gives you more flexibility in design.
I do agree with this; sheilds can have their uses in prototyping, but when building a "final design", you are likely to put the Arduino in as a "standalone" on the PCB along with other components - no sheilds needed or required. I think shields were one of those things that seemed like a "good idea at the time"; and for prototyping/teaching, probably so - but they make no sense in a final design (nor does the Arduino carrier board, for that matter).
