Large 7-Segment Display Circuit ULN2803 PIC16F876A

Large-size display prices are expensive, and they have a limit, but if you make a led display yourself, you can get large sizes. In the led diplay control, pic16f876 is used, the leds are driven with uln2803, the operating frequency of the circuit is 20mhz prepared with software ccsc.

This project has 6.7 segments. Except for the dot segment, all segments consist of fourteen 5 mm super bright LEDs, using only 4 LEDs. I designed this project with big 7 segment display, big digital clock, digital timer etc. I designed it for multi-purpose use. Project designed as a single digit module. You can cascade up to 8 modules or 8 digits. There are two options for each rung on the PCB, and you can use or ignore these options for each rung PCB.

– 3 switches on the PCB.
– 1 Opto-isolation input.

ULN2803 PIC16F876A Big 7segment

PIC16F876A will be used to control all tasks in this project. You can replace it with any 28 pin PIC microcontroller. PortB is set as output to drive all segments. PortC is set as output to drive each digit vai ULN2803, octal high voltage, high current darington transistor array.

Jumper 1(J1) on the PCB used to identify the step module (digit1 to digit8).

Solder pad at the bottom of the PCB use to cascade the step. Contains all segments of a,b,c,d,e,f,g,h,dot(p) and digit1-digit 8. To step step, simply solder the PCB pad and then select J1 to designate the step itself. If the digits are far apart for each digit, you can use copper wire or flat wire instead.

The sample firmware included in this project is the 4 digit counter written for the CCS C compiler. You can change the source code if you want more than 4 digits. To use with this example firmware you have to assemble 1 full PCB (all components installed) and the remaining 3 PCBs you only need to solder all the LEDs. being 2, 3 and 4 digits respectively.

Source: goo.gl/RaZIq Large 7-Segment Display Circuit alternative link: