Hello all! I am constructing a project in which I need to read a total of 15 inputs. Obviously I am running into floating pins. I am aware that my Arduino Mega has internal pull up resistors, but that will not work in the scope of my project. I will be setting a pin high, which will trigger an external circuit, thus returning a 5V signal as confirmation that a process has happened.
Three conditions must be checked:
the circuit is off (0V on input of arduino)
the circuit is on from triggering of the arduino (5V on input of arduino)
the circuit is off (0V on input of arduino)
This is to ensure that a relay or other mechanical device has not become stuck in a on or off position.
The problem I am having is finding a clean way to implicate 15 pull-down resistors onto the inputs of the arduino. Does this type of product exist? Thank you very much!
When space is at a premium, you will often see 9 pin SIP resistors used (8 resistors with one end of each resistor all tied to a common pin, with that common pin tied to GND or +5V as needed)
That is too wide. If you want to plug onto the 0.1" x 0.1" pitch headers at the end of the Mega,
then crimping on male pins to resistors, and connecting the other ends together to connect to +5, might be a way to go.
pins http://www.pololu.com/catalog/product/1931
housings
