Raven Luni
- Oct 15, 2011
- 798
- Joined
- Oct 15, 2011
- Messages
- 798
Greetings,
I'm pulsing the count up (CPU) pin of a 74HC193 using a schmitt trigger (so no bouncing) and it counts fine except that it misses 8 and 0 for some reason - goes straight from 7-9 and 15-1.
I dont have a schematic just at the moment but I'll give as many details as I can:
- Powered from a 7805 with 10uF and 1uF capacitors for extra smoothing
- Q outputs are connected to a bar graph display through 330 ohm resistors
- MR is connected to a reset switch (monostable 555)
- PL is tied high
- CPD is tied high
- CPU is connected to a schmitt trigger which takes its input from the PC sound card (feeding it a square wave)
Everything else is unconnected.
I've tried swapping the chip as well.
I'm pulsing the count up (CPU) pin of a 74HC193 using a schmitt trigger (so no bouncing) and it counts fine except that it misses 8 and 0 for some reason - goes straight from 7-9 and 15-1.
I dont have a schematic just at the moment but I'll give as many details as I can:
- Powered from a 7805 with 10uF and 1uF capacitors for extra smoothing
- Q outputs are connected to a bar graph display through 330 ohm resistors
- MR is connected to a reset switch (monostable 555)
- PL is tied high
- CPD is tied high
- CPU is connected to a schmitt trigger which takes its input from the PC sound card (feeding it a square wave)
Everything else is unconnected.
I've tried swapping the chip as well.