I'm going to be working on a simple project where I need to send and receive basic I/O. The hardware both sends and receives 8v triggers thou we can change that to whatever the board/shield needs. Basicly "in" signals come from buttons and the "out" signals go to motors but we just need to trigger them not really control them. Looking for a total of 20 I/O, 10 in, 10 out. This will be my first project with arduino products but im comfortable with programming and learning the IDE tools.
If it matters it will have an adobe air frontend. I took a look over the current offerings and it seems most are heavy digital I/O. Any product suggestions for a large set of analog I/O (both controller and shield if needed)?
If I am leaving any important details out please let me know.
The Arduino Mega works on a 5V level. Voltages above 3V or so will be considered "high" while those below 0.8V (or so) are considered "low". Voltages should not exceed 5V else the device will be damaged.
For "triggers" (I'm assuming you mean regular pushbuttons?) it is common to just connect a pushbutton to a digital input and the other end of the pushbutton to ground. Enable the built-in pullup resistor on the digital input and the input will naturally read high when the button is not pushed. When the button is pushed the digital input will read low.
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The Gadget Shield: accelerometer, RGB LED, IR transmit/receive, speaker, microphone, light sensor, potentiometer, pushbuttons
Yes thank you, i'm sure im not using the right terms. So to avoid over voltage and isolate it in my head im thinking that the best choice is to slap this in a bomb proof case, use a set of micro relays hooked to 1/2 inch jacks (for our application) that the buttons will connect too. Pushing the button closes the loop that triggers the relay that sends the ground. Does that sounds like the typical solution? I imagine there would be a simple way to y to trip a relay using the board so I could send an "output" as well?
Well i'm talking about giant crosswalk style buttons in an outdoor environment that run at 8 volts. The buttons will be anywhere from 5 to 50 feet away. I'm not sure yet how a common ground is going to work. Am I really that crazy?
Only if you use relays. If ou are worried you just use the switches to drive the base of a transistor into the input pins. You need a common ground so no need to worry how it works.
The mega2560 is nice, but probably oversized for just reading 10 switches and turning on/off 10 devices.
Most 168/328 based boards are more then capable enough. The 20 pins available on those boards may not be enough since you want to use adobe air front end as well, but one can easily add loads of I/O pins with a few cheap components.