[RESOLVED] Some numbers inverted 7-segment display with BCD decoder

Other Hardware Displays
1

Hello,

I have a problem with my LTS-546AP 7-segment display (single digit, common anode) that I use with a CD4543BE BCD decoder. I wired everything correctly (normally). By sending the corresponding bits to the desired digit on pins A, B, C and D of the decoder, I can correctly display 1, 3, 5, 7, 8 and 9, but not 2, 4 and 6. By the way, the display is inverted for these 3 digits: the leds that should be on are off and vice versa (so it "draws" a 4 for example but in leds off). I tested with two displays (same LTS-546AP component), two decoders (CD4543BE) and two Arduino cards (Uno and Mega): same result...

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My (simple) code to display 2 :

const int bit_A = 2;
const int bit_B = 3;
const int bit_C = 4;
const int bit_D = 5;

void setup() {
  pinMode(bit_A, OUTPUT);
  pinMode(bit_B, OUTPUT);
  pinMode(bit_C, OUTPUT);
  pinMode(bit_D, OUTPUT);
  pinMode(ph, OUTPUT);
  
  digitalWrite(bit_A, LOW);
  digitalWrite(bit_B, HIGH);
  digitalWrite(bit_C, LOW);
  digitalWrite(bit_D, LOW);
}

void loop() {}

Do you have a solution to this problem?

Thank you in advance,

Lounès

Datasheet LTS-546AP : https://datasheet.octopart.com/LTS-546AP-Lite-On-datasheet-32599812.pdf
Datasheet CD4543BE : http://www.ti.com/lit/ds/symlink/cd4543b.pdf

2

I wired everything correctly (normally).

It's hard for us to check this part out since you haven't provided a photo but my hunch is that your problem is related to pin 1 (phase) on the CD4543BE.

Don

3

I checked again everything pin by pin and realized that I was using the wrong decoder pin for the Phase (I confused it with the latch). After connecting the ph to the 5V, everything went back to normal. Thank you!