Shift Register not working

Thread Starter

Raul Junc

Joined May 19, 2015
3
Hello I have a problem with the shift register. When I turn on the device sometimes I get random data already(ex QB, QC is high) this is the case when the shift register works as expected, but when I turn on the device and get from start every Q output as low, the shift is not working at all(can't insert 1's). What is even more weird is that when I already have something in it if I shift 0's till all are low, again is not working at all, can't insert other 1's. I connected pin 10(SRCLR) to +

The circuit used is SN74HC595N
Here is a link to the schematics i used: http://html.alldatasheet.com/html-pdf/27939/TI/SN74HC595N/24/1/SN74HC595N.html
 

MrChips

Joined Oct 2, 2009
30,712
If you are creating a PRNG, then a register with all 0's will remain in that state.
You have to ensure that you never have all 0's even on power up.
 

AnalogKid

Joined Aug 1, 2013
10,987
Those are images of the chip. I'm asking about *your* circuit, not the datasheet. The connections to the chip the other parts around it. What is the circuit, and what is its function? What are you trying to achieve?

ak
 

Thread Starter

Raul Junc

Joined May 19, 2015
3
Those are images of the chip. I'm asking about *your* circuit, not the datasheet. The connections to the chip the other parts around it. What is the circuit, and what is its function? What are you trying to achieve?

ak
upload_2015-5-19_19-22-0.png
I just want to make a shift register, see that it works like I expected, I don't have anything connected to it. Here is a picture with what i have so far.
 

dl324

Joined Mar 30, 2015
16,845
Why won't you post a schematic? People want to help you, but asking someone to trace your breadboard to make a schematic is asking for too much...
 
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