Custom 7 segment driving problem

Hi,

i have a 4 digit common anode custom 7 segment display and it is similar like in the link:7 segment custom display

it has 12 pins. 7 of them are segment pins 4 of them are digit pins and the one left is the common pin for characters.

there are 5 special characters and their pins are mutal with segment pins a to e. i connect common pin of characters and all other pins to arduino and i am trying to make a timer/clock circuit. But when i try to write "8" on display and light just one of special characters, all characters are lighting up because all segments are lighting and characters are mutual with them.

How can i light the special characters up seperately? I know i should be able to do it because i found a circuit made by a chinese guy is working like this.

This is going to be realy hard for us without a datasheet or spec...

part number is ELF-568SURWB/530-A3 but i could not find a datasheet of it on the internet. I bought it from an electronic component shop and there was not any document there also.

Again, it's going to be hard. But not impossible.

Try selecting the digits one-by-one and make a mapping. I like to draw it out as I go.
It's gonna take time but it's the only way (I can think of) without a datasheet.

Make a program, select 1 pin as common anode and 1 as digit. Then, upload another program with another digit and so on.

I already mapped the pins:

pin1: segment a & character "P"
pin2: segment b & character "Auto"
pin3: segment c & character "alarm"
pin4: segment d & character "."
pin5: segment e & character "cooking pot"
pin6: segment f
pin7: segment g
pin8: digit1
pin9: digit2
pin10: digit3
pin11: digit4
pin12: character common pin

I think you need to study the concept of multiplexing.

Then you need to get a MAX7219 and figure out how to connect it.

Do not be put off by the concept that the MAX7219 is better suited for common-cathode displays - it works perfectly well for common-anode.

I don't have any idea about this

miwieland:
I don't have any idea about this

I suppose you don't.

So what is your point?