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Member Since: April 19, 2014

Country: Norway

  • Chances are you got the wiring wrong.

  • This can be implemented with a binary counter like 74HC393, so you don’t have to tie up the processor time of a microcontroller. Connect the GRAY wire from the Coin Acceptor to one of the inputs of the 74HC393, then program the Coin Acceptor to use 1, 2 and 4 pulses for the three different coins. This will output 0001, 0010, or 0100 from the binary counter pins. If you have a microcontroller, you can just check the state of these three pins on the 74HC393, and the microcontroller can do other stuff than just check for pulses.

  • In the schematic they are pulled to Vdd with a 100k resistor, so that’s correct.

  • What is the point of the buffered I/O’s, as opposed to using the GPIO’s directly? What does the “buffering” do?

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