You are viewing a single comment's thread from:RE: Custom 28 Relay Controller Board for Raspberry Pi 3View the full contextView the direct parentwhytehorse (51)in #technology • 9 years ago So what's the problem that causes you to only be able to use 25?
When powering on/off the Pi the GPIO pins 2, 3, 14 change state temporary... switching on and off the relays on them.
I didn't understand it!?
OIC, the only solution for that is to invert the signal at the hardware level. Such an inverter can simply be built with a single transistor and two resistors, or you can use a chip with six of them, like a 74HC04 (powered with 3,3V).
ঈত
it is too much costly here in Bangladesh!!