Common Anode Improvised 7 Segment

Hi sir,

I am currently working on a project. I made a improvised 7 segment using LED. The display is working on a 12v supply. But arduino just give around 0.7v to 5.0v. Anyone can help me with this project. Thanks a lot. God Bless Us All.

Charles

Charles,

This post may help: http://forum.arduino.cc/index.php?topic=323585.msg2236098#msg2236098

Archibald: Charles,

This post may help: http://forum.arduino.cc/index.php?topic=323585.msg2236098#msg2236098

Hi sir thank you for the circuit. Can tell me how does it work? Thanks.

Hi, have you made the display as common anode or common cathode, or can you easily adapt it to be either?

If it common anode, or you can make it common anode, the easiest solution could be to use either:

  • 7 npn transistors such as bc337, driven by 7 Arduino pins
  • a ULN2803 chip, driven by 7 Arduino pins
  • a TPIC6C595 or TPIC6B595, driven by 3 Arduino pins

If you want to drive many of these displays, the last solution will be best, because the same 3 Arduino pins can drive many of the TPIC chips and you would need one chip per display.

Paul

PaulRB:
Hi, have you made the display as common anode or common cathode, or can you easily adapt it to be either?

If it common anode, or you can make it common anode, the easiest solution could be to use either:

  • 7 npn transistors such as bc337, driven by 7 Arduino pins
  • a ULN2803 chip, driven by 7 Arduino pins
  • a TPIC6C595 or TPIC6B595, driven by 3 Arduino pins

If you want to drive many of these displays, the last solution will be best, because the same 3 Arduino pins can drive many of the TPIC chips and you would need one chip per display.

Paul

Hi Paul,

I guess this will be helpful. Thank you. But can you show the wiring and a sample program as well? Thanks in advance :))

Charles

Basic setup, see attached.

code for fontArray

byte fontArray[] = {
0b00111111, // 0    DP-g-f-e-d-b-c-a, 1 = segment that is on.
0b00000110, // 1    Writing 1 to TPIC6C595, TPIC6B595, turns output on (drives it low)
0b01011011, // 2
:
:
0b01101111, // 9
};

Can use PWM to drive OE for brightness control. If using LED strips for segments, the segment is typically 3 LEDs in series with a resistor and designed to run from 12V.

CrossRoads: Basic setup, see attached.

Hi sir, how about if im going to use 2 segment? How is the wiring? Because I want the display the value of an analog input into the improvise 7segment.

Thanks,

Charles

Did you mean 2 digit?

You can chain two tpic chips. Data Out from the first chip goes to Data In on the second chip. Clock and Latch pins on the second chip connect to the Clock and Latch pins on the first chip.

In your sketch, you must send two bytes of data before you latch the data. The first byte sent will go to the second tpic chip.