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Thank you. I see what you mean. The same applies to the eeprom I used but in its case it did not do anything with the data at its input/output pins until they were selected as such and there was a 'read' signal pulse. I suppose the same applies to the MCP23017. I have not had the time nor inclination to fully understand how the 23017 operates and is used to offer any immediate advice. I remain sceptical though.First off all, congratulation on the movie and showing the full working project. Very fascinating !!!
I still have to try it your way someday, in the future.
-to your question now: - Well, when a pin of the IC is floating , it is not 0V nor 5V. Right? But by having all those leds and resistors to 0V, I efectively put to 0V every IO pin of the chip. THus, not leaving anything really floating. This is important in code, when I am switching from Outputs to Inputs. By switching to Inputs is the programming way of 'floating' the Output. By inversing it. Its a trick learned when I was programming PIC's MCU's. But... having all these pins to 0V ---anyway--- , it doesnt matter if I was switching to Input or to Output in code, because the state was 0V anyway. So the speed was not affected but the entire logic of the code was affected, which is more important and more drastic. I hope is more clear now what I did there.
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