I purchased this because my girlfriend asked me to include a simple counter in a project i am making. I am VERY new to electronics, this is my first arduino, and i admit, I am struggling. I didn't think a counter would be so rough, but so far, it seems to be the hardest part, I think because maybe its so basic, that most tutorials take basic electronics knowledge for granted. I however lack
I understand ( i think) how a single digit, or even multiple digit 7 segment display works, but this one seems to be missing some pins from every tutorials or info i could find.
abcdefg are segments,dp is the decimal point, DS1 and DS2 select which one
so lets say its common cathode, if you apply ground on DS1 and power to segment A, one segment on the first number with light up, if you change DS1 to DS2 the same segment should light up on the second number
toggle back n fourth fast enough and you will never see it flicker
Its wired as a simple matrix if it helps you pucture it, say 8 rows and two columns
the two columns would be the negative side and the 8 rows the positives
and by "scanning" through the rows and columns providing power when you want that segment on you can make it appear to all be on at once if you do it fast enough
if you want it off keep it the opposite voltage, so say you want the first digit on you would have the arduino apply a digital low(0v) to ds1 and digital high (5v) to ds2, then current will flow from the appropriate segments that provide 5v to ds1 and light up that digit, and since ds2 is high no current will flow and the second will not light up
similar would apply to the individual segements, high when on and low when off
also don't forget current limiting resistors on the segment pins to limit current through the arduino pins and the leds, anywhere between 220 and 1k ohms will work fine
If you control ds1 and ds2 direct from arduino pins then the segment resistors should be 1k or more, since ds1 and ds2 are taking the current for upto 8 segments simultaneously and you must limit Arduino pin current to about 30mA to avoid damage (40mA is the absolute maximum). If you use a transistor to switch ds1 and ds2 then you allow higher segment currents.
