7SEGMENT

April 12, 2025

1. Display Not Lighting Up

Q: No segments are illuminated.
A:

  • Verify SEG_Init() was called first
  • Check common anode/cathode configuration matches SEG_MODE
  • Confirm power supply (2-5V depending on LEDs)
  • Test with SEG_BUFF = {_8,_8,_8,_8,_8,_8} to force all segments on

2. Incorrect Digits Displayed

Q: Wrong numbers appear or segments are missing.
A:

  • Check SEG_LOOKUP[] table matches your display’s segment wiring
  • Verify SEG_PORT pins are correctly mapped
  • For common anode displays, ensure SEG_MODE 1 is set

3. Flickering Display

Q: Digits flicker or appear dim.
A:

  • Adjust SEG_TIMER_TH/TL values for faster refresh rate
  • Add current-limiting resistors (220Ω typical)
  • Check for loose connections

4. Decimal Point Issues

Q: Decimal points don’t work or appear in wrong positions.
A:

  • Format numbers with period: SEG_OutData("12.34")
  • Verify _DP bit is set in your segment definitions
  • Check SEG_PORT includes the decimal point pin

5. Negative Numbers Not Showing

Q: Minus sign doesn’t appear.
A:

  • Format with leading minus: SEG_OutData("-123")
  • Confirm _MINUS is defined in your segment patterns
  • Left-justify numbers when using negative sign

6. Timer Configuration

Q: How to adjust refresh rate?
A:

7. Custom Character Display

Q: How to show letters or symbols?
A:

8. Multiplexing Artifacts

Q: Ghosting or bleeding between digits.
A:

  • Add small delay (1-5μs) when switching digits
  • Use transistors for segment drivers if current is high
  • Verify all digit control pins are properly toggled
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