Guest bubleman Posted April 17, 2003 Report Share Posted April 17, 2003 I build mb64 on gregs pcb and connect another 40 d.inputs (5x74165) based on DINX_4_v2 design. When I was testing I found that some buttons is scanned even if I press nothing :o. Than I disconect the buttons and the same effect occured. Actualy just the same note was scaned. When I disconect extension the jittering was smaller but still was there ???. Of course that din is ended by clamp to Vcc. Please help me with solving this problem.B.R. Sodaman Quote Link to comment Share on other sites More sharing options...
TK. Posted April 19, 2003 Report Share Posted April 19, 2003 The random notes could be caused by an "unterminated"DIN chain. So far as I remember greg's layout doesn't come withthe regired 10k pull-up resistor on the input of the last 74HC165(Pin 10). It should help :)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
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