chained shift register functions

Projects Programming
1

Hi

I want to use daisy chained shift registers to control display-tubes

Each tube has 10 digits, so i need 1 whole shift register, and 2 pins from next.

There are 6 tubes, so the wiring looks like this:

REG1 [PIN1-8] connected to TUBE1, DIGIT 0-7
REG2 [PIN1-2] connected to TUBE1, DIGIT 8-9
REG2 [PIN3-8] connected to TUBE2, DIGIT 0-5

and so on...

How can i make a function, where i just give the 6 Values for the tube and then the right shif-outs will be calculated?

Like

displayNumbers(1,2,3,4,5,6) {}

thanks for the help

2

You do it the same way as you do with one shift register, except you don't output a latch pulse until all the registers are loaded.

3

Why no multiplexing ? (nixie-tubes? are well suited for that)

4

aarg:
You do it the same way as you do with one shift register, except you don't output a latch pulse until all the registers are loaded.

Yes, i got that, but if ... for example...

Tube1, DIGIT 8, is connected to output 1 on IC2, then i had to send 00 00 00 01 to shift out, to turn on digit8,

If Tube2 Digit 0 is connected to output 2 on IC2, then i had to send 00 00 00 10 to shift out to turn on.

But what if i have to display Tube1, 8 and Tube2, 0.

while x = 08{
shiftout 00 00 00 01
delay(1)
shiftout 00 00 00 10
delay(1)}

because to display both, the shift out should be 00 00 00 11.

Can i merge these two in any way?

knut_ny:
Why no multiplexing ? (nixie-tubes? are well suited for that)

Nixie-Tubes are NOT suitable for multiplexing!

5

I remember them from petrol-pumps back in the old days.. flickering.. multiplexed.

If you need a chain of 8 registers (60+ bits), you prepare the 8 bytes and shift them all out - then latch.
Write the procedure that sets the correct bit in an 8 byte array.

6

For driving nixie tubes, take a look at this: http://switchmodedesign.com/products/smart-nixie-tube

There's code, PCB layouts, and design documents for Arduino controlled nixie drivers there. I have the smart nixie tubes in a chain for my desk clock (with one of the tubes with % and deg C on it, too for showing temp+RH :smiley: )