C
Charl
Guest
Hello folks,
I'm working on interfacing one of those small numeric keypads which
are used for laptops. I'm using two 74164 shift registers, of which at
the moment I only have one connected.
It seems to be working properly, I'm getting the lower part of the
byte, parity and stop bit. But whenever I press a key, I see the LEDs
which I have connected to Q0~Q7 flicker quite a lot (the ones that are
on don't flicker; the ones that are off do). I think that this is a
little strange since according to Beyondlogic.org the CLK signal
should be around 20 KHz.
The flicker means that I will only be able to press a key every half a
second (since that's how long the flicker lasts).
Does anyone have a solution for this?
Regards,
Charl
I'm working on interfacing one of those small numeric keypads which
are used for laptops. I'm using two 74164 shift registers, of which at
the moment I only have one connected.
It seems to be working properly, I'm getting the lower part of the
byte, parity and stop bit. But whenever I press a key, I see the LEDs
which I have connected to Q0~Q7 flicker quite a lot (the ones that are
on don't flicker; the ones that are off do). I think that this is a
little strange since according to Beyondlogic.org the CLK signal
should be around 20 KHz.
The flicker means that I will only be able to press a key every half a
second (since that's how long the flicker lasts).
Does anyone have a solution for this?
Regards,
Charl