Arduino nano and TPIC6B595 x2

Hi all :slight_smile:

I try to buil Whac-A-Mole with led and arduino :slight_smile:

I have 4x4 12v led (arcad led) that I want to use with a two TPIC6B595.

tpic Arduino nano (v3)
pin 4, 5, 6, 7, 14, 15, 16, 17 to led
pin 10, 11, 19 gnd 12v
pin 9 arduino GND
pin 2, 8 arduino +5v
Pin3 (data) Arduino pin 11
latch (pin12) Arduino pin 10
latch (pin13) Arduino pin 12
tpic 1 pin 18 to tpic2 pin 3 None

For arduino code, I juste try this

#define DATA 11
#define LATCH 10
#define CLOCK 12

int digits[] = {

void setup() {
   pinMode(DATA, OUTPUT);
   pinMode(LATCH, OUTPUT);
   pinMode(CLOCK, OUTPUT);

void loop() {
   int i;
   for (i = 0; i < 16; i++) {
      digitalWrite(LATCH, LOW);
      shiftOut(DATA, CLOCK, LSBFIRST, digits[i]);
      digitalWrite(LATCH, HIGH);

My problem is :

When I swith on all, all led are on :frowning:

Have you any idea of where is my mistake ?

My goal is to make a random led on

5V and 12V grounds not connected?

No bypass caps on shift registers?

It would really help us to help you if you could draw a proper schematic. Fritzing can do that too. Use "Schematic view" instead of "Breadboard view".

Thanks for your quick answer.

You right for all gnd :frowning:

I have refer to this picture :

I have connect 9, 10, 11, 19 to the GND.

I don't know what is a bypass caps on shift registers? (Sorry for my ignorance)

I try to make quicky a proper schematic in Schematic view. For now it is completely illegible.


This is my shcema

If I have make some mistak tell me.

Ah, the tpic chips' pins are not labelled. Does Fritzing not have a component symbol for the tpic chip? If not, will it allow you to add pin labels?

For bypass caps, you should have 0.1uF closely connected to the 5V & ground pins of each chip.

Fritzing Does not have this component (TPIC6B595)

I have add the pins labels :slight_smile:

And I have update my schematic with bypass caps (value is not right). Can you verify if it’s good now ?

The less value I have is 50v 1uF, do you think it’s ok with this value ?

Thanks again

1uF is too large. Bypass caps should be around 0.1uF = 100nF. You need one cap for each chip. They should be physically as close as possible to the 5V and ground pins of each chip (it does not matter where you draw them on the schematic). They are normally the ceramic type. The cap in your schematic is connected between 5V and 12V supplies. That will damage the chips or the Arduino.

Ho, you right my schematic have a mistak sorry. I have send a new one.

I don’t do this in real :slight_smile:

but when I connect all ground without the caps, nothing work.
And when I disconnect the ground to the arduino. It’s work but all completly random :frowning:

I try to found some caps …

thanks again for your help

Please post your pictures and schematics so that we can view them. Until now I am doing this each time for you.