Seven segment

Hello I have built my scoreboard using an Arduino uno and some sparkfun shift registers. I will ask my question about the 3 digit board. As the board faces the field of play I have had to add a small duplicate board on the inside of the scorebox so the scorer knows what is on the outside. At the moment I have run wires from each segment on the 3 shift registers down to each segment on the 3 small seven segments. I would like to reduce the amount of wiring. I would like to use a 3 segment unit, is it possible to wire it from just one of the shift registers or could I wire it direct from the Arduino?

Use a 1602 LCD with I2C backpack, and have the Arduino display the score there as well. Then you have space for more messages even, as needed.

I would like to use a 3 segment unit

I think you meant to say 3 digit unit ;)

No, you can't use that. Multi-digit displays have common anodes and common cathodes, so they must be multiplexed. The signal driving your outdoor display is not multiplexed, I think.

But if you use 3x single-digit displays for your duplicate displays, then it should be straight-forward. You will need 3 more shift registers (I assume you mean 74hc595 or similar). Chain your 3 new shift registers and connect the inputs of the first in parallel with the first shift registers driving the outdoor display (data, clock & latch).

Thank you Paul rb That is a simple way and will reduce my wiring down. I take it I can come directly of the Arduino with the wires, as I have fitted it with a screw header platform. I duplicate all the wires ( 12v, 5v,gnd,latch,data,clock.).

If you really want to reduce the wiring, and have like, twenty more bucks to spare, both Sparkfun and Adafruit (and I assume others as well) sell 4 digit displays that communicate via I2C. This will drastically reduce your wiring and component count, and make programming easier.

groundsman: I duplicate all the wires ( 12v, 5v,gnd,latch,data,clock.).

You will not need 12V for your small indoor display. But you will need all the other wires, yes.

You will also need 7 or 8 series resistors for each display. I would recommend 390R or 470R.

Hi Paul RB Not sure why I don’t need a 12v supply as the outside lights have one which powers the led strips. Could you explain this to me please? All these bits of information help me learn more.

The outside strips need 12V because they are strips. Normally, strips have groups 3 LEDs in series (that’s why you have to cut them after a group of 3). To light a group of 3 LEDs, you need a higher voltage such as 12V. But small 7 segment displays contain only one led in each segment. You could power those segments from 12V but it would be a waste. They only need <5V to run.

Hi PaulRB
I have just found this on the sparkfun Webb site (shift register breakout 74HC595.) It looks just what I need. The only thing I’m not sure on.It has 7 inputs from the Arduino ser-in(data) l-clock(latch) clock. GND, VCC (5volt) do I need to connect the OE and Reset pins and if so where do I connect them to. Thanks for your advice and help.

You mean this?

Please learn to post links to products you refer to, don't force people to search for them. The forum guide in the sticky post tells you how, and lots of other useful things.

You can connect OE to ground and Reset to 5V.

Sorry will do it in the future. I’m still learning