2020-10-12, 12:01 PM
(2020-10-12, 02:10 AM)CapnKernel Wrote:I believe the resistor Sean suggested was a current limiting resistor to GND avoiding a direct short to ground by the switch.(2020-10-09, 10:03 PM)rastam4n Wrote: Did you need to adjust anything software wise to get this switch array to work? Can you show my how you wired it to the gpio pins?
No, just connected it, like this:
https://forum.openmarine.net/showthread....3#pid11963
(2020-10-10, 01:04 AM)rastam4n Wrote: Thanks Sean, That would work fine, so what value of resistor should I put in series and what side of the switch should the resistor be placed? Between the gpio pin and the switch or between the switch and ground?
In another thread, Sean suggested a resistor between the GPIO and the keypad pin to provide some protection against possible short circuits. I used a 1k resistor array and it works ok:
I've connected the LED to GPIO7, but I don't know if that's the recommended pin, or if the pin has sufficient drive current.
I have a number of these membrane keypads and they all have a resistance from 27-47 Ohm per switch, so no need for the resistor to GND.
My keypad has an LED as well with a separate wire for the power, not using it at the moment.