Hiya, I have built a very simple 4 step sequence with a 555 and 4017. The lights count up to 4 then there’s a 2 second gap then they count again. The reset is not resetting so there’s not a fluid sequence of lights. I have a wire coming from reset to pin 10 of the 4017(output4) as it should reset there, but it does not? The wires from the outputs to led’s are pin 3, 2, 4 and pin 7. Clock of the 4017 to pin 3 of 555. Any ideas why it’s not resetting will be most appreciated, thanks.
Try a different 4017? Got any spares? I have burnt out my fair share of 4017s with the 555 clocking it when I first experimented around with the simplest setup. It seems that you have a diode to protect for this, however…
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With problems like these the first thing to suspect is the connections. Is pin 10 really connected to pin 15? Check continuity with a multimeter (with module power off, and maybe with the chip removed). While you’re at it check continuity to make sure neither pin is connected to something it shouldn’t be, like ground or a voltage rail.
Are you sure there’s really a pulse at pin 10? You can check by adding a resistor and LED like on the other pins.
You also can try sending the reset from pin 3, 2, 4, or 7 since you know there’s a pulse there. Or you can try sending a pulse from some other source into pin 15. Some gate or trigger or even LFO square wave from a module or synth where you know the signals are sharp and robust. If it’s a slow enough, wide enough pulse you can probably verify it gets to pin 15 with a multimeter measuring voltage. Or you could put a resistor and LED on pin 15 too.
Basically it appears either there’s something wrong with pin 10, or with pin 15, or with the connection between them. You can try to figure out which with various tests — If you can get it to reset with some other signal to pin 15 then pin 15 is working (at least at some level); if you can light an LED with pin 10 then it’s working (at least at some level); with the continuity check you can verify the connection is good. If one of the three fails that tells you where to focus.
Hiya, yeh I read it’s best to put a diode in for protection and a pulldown100k. I did put in another 4017, but the same thing happens with the gap in sequence. I’ll try some of the ideas that 'analogoutput suggested. Thanks for the help.
Hiya,. I’ll have to check if my multimeter is working, if not I’ll try the other ideas you suggested. I’ll get back on my results, thanks.
Hiy again. I did all the tests minus the multi meter. There are pulses on the outputs, the 555 is clocking nice while using a pot high to low. Thing is you can’t upload films, as I could post it here. I’m on the Lunetta facebook group where I posted it there, if you have time to look. So getting back to it: The LEDs count up to 4 nicely but there is still a 2 second gap until it starts counting again! I tried another 4017, but it still happens. Checked I have reset to pin 10 ( there is a pulse at 10), so it should work? Thanks.
Hiya, I have it working now. Must’ve had two components touching. Breadboards can be a pain sometimes. I’m going to eventually put 4 pots. from the 4017 then into the VCO in of a 4046 or IN to 40106. Hopfully that’ll work?
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If you don’t have a working multimeter, get one. The cheapest one in the world is probably adequate as long as it works. It’s really indispensable for this stuff.
It’s a good idea to cut the resistor leads short enough that they’re up against the breadboard, helps prevent that sort of thing.
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Ok, thanks will do. It’ll be better when it’s soldered on the board.