7 Segment display with multiple digits

Other Hardware LEDs and Multiplexing
1

Hello,
I am trying to count up on a 4 digit 7 segment display. The display is multiplexed, and I included a link to the below. Unfortunately, I went kind of cheap with the displays. All digits work, but I'm not sure how I should go about displaying multiple digits at once. I was wondering how to parse an integer so that I could get the first(tens) and second(ones) number.
Here's an Example:

If the number was 16, I would want to separate the 1 from the 6, and return them separately. How should I go about this?

I would appreciate all the help I can get.
Thanks.

2

Taking the example you gave (16), the smallest digit is 16 modulo 10 (remainder is 6). Modulo operator is % in C.

This is normally processed 'backwards' in a loop as follows (assuming num is the number you are displaying):

uint8_t digit;

while (num != 0)
{
  digit = num % 10;  // lowest digit isolated - do something with this
  num = num / 10;  // get a new lowest digit
}
3

Thanks. This really helped...

4

You did not mention how you are connecting the display.

The best way is to use a MAX7219 chip which handles all the multiplexing of digits for you, so you only have to set its registers once for each new display value. Driving the digits directly with Arduino outputs is really only an experimental and transitional learning exercise.