Can I use MOSI and MISO on the header and repurpos D11 and D12 as digital pins?

Using Arduino Installation & Troubleshooting
#1

I am running out of pins, so I attached a simple relay to pins D11 D12. I need MOSI and MISO for wireless communication (RF24). Somehow the relays don´t really woek anymore. Is MOSI and MISO on both the header and D11, D12??

What can I do to still use them? Can I run the relays from A4-A7?

#2

Which Arduino board are you using?

#3

Yes, the Analog ports can be used as digital outputs.

How much current do the relays need? Most relays cannot be driven directly from Arduino pins but instead need some kind of transistor buffer.

#4

I am using this one and it works on its own. It reliably clicks. Is this proof that I don’t need extra power? https://www.exp-tech.de/module/relais/4261/5v-2-channel-relay-shield-fuer-arduino?gclid=EAIaIQobChMI49uMzu2s2gIV7Z3tCh1UyQ1FEAQYASABEgKLX_D_BwE

Any info about MISO?

#5

pert:
Which Arduino board are you using?

#6