4017 counter reset at 8

[Mikebtb]

Hi can anyone tell me how to reset the 4017 decounter when it gets to ouput 8? I am using a 555 timer to control it of course.

Thanks in advance

 

[audioguru]

Simply connect the output 8 pin to the reset pin.

 

[Mikebtb]

Ok that does work and is very helpful audioguru thanks. Maybe I need something else. I am building 8 stage sequencer so what I really need it to do is when it gets to 9 it goes back to 1 instead. Connecting 8 (my fault for saying end at 8 when I meant nine) works but there is a one step delay.

 

[AnalogKid]

maybe you have the wrong output connected to Reset.

4017 outputs go high, and the reset input requires a high. Remember that a 4017 starts counting at zero. When the counter is reset, the zero output goes high and stays high as long as Reset is high. After Reset goes low, the next clock edge makes the "1" output go high. So if output 8 is tied to Reset, on the 8th clock edge it will go high, reset the counter, and immediately go low. Whatever output is tied to reset makes very short pulse, much less than 1 microsecond, when it forces a reset.

ak

 

[Mikebtb]

Agggh it does work. I didn't realise (which is really silly of me since I am a programmer) that outputs start at 0. I did connect the output of 9 to the reset pin but it wasn't working possibly because I had a ground in there by mistake. Thank you Audio Guru and AK